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ladybird/Userland/Libraries/LibSoftGPU/Device.cpp
Jelle Raaijmakers aa3a6767f6 LibGL+LibGPU+LibSoftGPU: Implement blend equations 
This implements support for `glBlendEquation` and
`glBlendEquationSeparate`. These functions modify the calculation of the
resulting color in blending mode.
2024-02-19 23:23:40 +01:00

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/*
* Copyright (c) 2021, Stephan Unverwerth <s.unverwerth@serenityos.org>
* Copyright (c) 2021, Jesse Buhagiar <jooster669@gmail.com>
* Copyright (c) 2022-2024, Jelle Raaijmakers <jelle@gmta.nl>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/AnyOf.h>
#include <AK/Error.h>
#include <AK/Math.h>
#include <AK/NumericLimits.h>
#include <AK/SIMDExtras.h>
#include <AK/SIMDMath.h>
#include <AK/String.h>
#include <LibCore/ElapsedTimer.h>
#include <LibGfx/Painter.h>
#include <LibGfx/Vector2.h>
#include <LibGfx/Vector3.h>
#include <LibSoftGPU/Config.h>
#include <LibSoftGPU/Device.h>
#include <LibSoftGPU/Image.h>
#include <LibSoftGPU/PixelConverter.h>
#include <LibSoftGPU/PixelQuad.h>
#include <LibSoftGPU/SIMD.h>
#include <LibSoftGPU/Shader.h>
#include <LibSoftGPU/ShaderCompiler.h>
#include <math.h>
namespace SoftGPU {
static i64 g_num_rasterized_triangles;
static i64 g_num_pixels;
static i64 g_num_pixels_shaded;
static i64 g_num_pixels_blended;
static i64 g_num_sampler_calls;
static i64 g_num_stencil_writes;
static i64 g_num_quads;
using AK::abs;
using AK::SIMD::any;
using AK::SIMD::exp_approximate;
using AK::SIMD::expand4;
using AK::SIMD::f32x4;
using AK::SIMD::i32x4;
using AK::SIMD::load4_masked;
using AK::SIMD::maskbits;
using AK::SIMD::maskcount;
using AK::SIMD::store4_masked;
using AK::SIMD::to_f32x4;
using AK::SIMD::to_u32x4;
using AK::SIMD::u32x4;
static constexpr int subpixel_factor = 1 << SUBPIXEL_BITS;
// Returns positive values for counter-clockwise rotation of vertices. Note that it returns the
// area of a parallelogram with sides {a, b} and {b, c}, so _double_ the area of the triangle {a, b, c}.
constexpr static i32 edge_function(IntVector2 const& a, IntVector2 const& b, IntVector2 const& c)
{
return (c.y() - a.y()) * (b.x() - a.x()) - (c.x() - a.x()) * (b.y() - a.y());
}
constexpr static i32x4 edge_function4(IntVector2 const& a, IntVector2 const& b, Vector2<i32x4> const& c)
{
return (c.y() - a.y()) * (b.x() - a.x()) - (c.x() - a.x()) * (b.y() - a.y());
}
template<typename T, typename U>
constexpr static auto interpolate(T const& v0, T const& v1, T const& v2, Vector3<U> const& barycentric_coords)
{
return v0 * barycentric_coords.x() + v1 * barycentric_coords.y() + v2 * barycentric_coords.z();
}
static GPU::ColorType to_argb32(FloatVector4 const& color)
{
auto clamped = color.clamped(0.0f, 1.0f);
auto r = static_cast<u8>(clamped.x() * 255);
auto g = static_cast<u8>(clamped.y() * 255);
auto b = static_cast<u8>(clamped.z() * 255);
auto a = static_cast<u8>(clamped.w() * 255);
return a << 24 | r << 16 | g << 8 | b;
}
ALWAYS_INLINE static u32x4 to_argb32(Vector4<f32x4> const& color)
{
auto clamped = color.clamped(expand4(0.0f), expand4(1.0f));
auto r = to_u32x4(clamped.x() * 255);
auto g = to_u32x4(clamped.y() * 255);
auto b = to_u32x4(clamped.z() * 255);
auto a = to_u32x4(clamped.w() * 255);
return a << 24 | r << 16 | g << 8 | b;
}
static Vector4<f32x4> to_vec4(u32x4 bgra)
{
auto constexpr one_over_255 = expand4(1.0f / 255);
return {
to_f32x4((bgra >> 16) & 0xff) * one_over_255,
to_f32x4((bgra >> 8) & 0xff) * one_over_255,
to_f32x4(bgra & 0xff) * one_over_255,
to_f32x4((bgra >> 24) & 0xff) * one_over_255,
};
}
ALWAYS_INLINE static void test_alpha(PixelQuad& quad, GPU::AlphaTestFunction alpha_test_function, f32x4 const& reference_value)
{
auto const alpha = quad.get_output_float(SHADER_OUTPUT_FIRST_COLOR + 3);
switch (alpha_test_function) {
case GPU::AlphaTestFunction::Always:
quad.mask &= expand4(~0);
break;
case GPU::AlphaTestFunction::Equal:
quad.mask &= alpha == reference_value;
break;
case GPU::AlphaTestFunction::Greater:
quad.mask &= alpha > reference_value;
break;
case GPU::AlphaTestFunction::GreaterOrEqual:
quad.mask &= alpha >= reference_value;
break;
case GPU::AlphaTestFunction::Less:
quad.mask &= alpha < reference_value;
break;
case GPU::AlphaTestFunction::LessOrEqual:
quad.mask &= alpha <= reference_value;
break;
case GPU::AlphaTestFunction::NotEqual:
quad.mask &= alpha != reference_value;
break;
case GPU::AlphaTestFunction::Never:
default:
VERIFY_NOT_REACHED();
}
}
ALWAYS_INLINE static bool is_blend_factor_constant(GPU::BlendFactor blend_factor)
{
return (blend_factor == GPU::BlendFactor::One || blend_factor == GPU::BlendFactor::Zero);
}
// OpenGL 2.0 § 4.1.8, table 4.2
ALWAYS_INLINE static Vector4<f32x4> get_blend_factor(GPU::BlendFactor blend_factor, Vector4<f32x4> const& source_color, Vector4<f32x4> const& destination_color)
{
switch (blend_factor) {
case GPU::BlendFactor::DstAlpha:
return to_vec4(destination_color.w());
case GPU::BlendFactor::DstColor:
return destination_color;
case GPU::BlendFactor::One:
return to_vec4(expand4(1.f));
case GPU::BlendFactor::OneMinusDstAlpha:
return to_vec4(1.f - destination_color.w());
case GPU::BlendFactor::OneMinusDstColor:
return to_vec4(expand4(1.f)) - destination_color;
case GPU::BlendFactor::OneMinusSrcAlpha:
return to_vec4(1.f - source_color.w());
case GPU::BlendFactor::OneMinusSrcColor:
return to_vec4(expand4(1.f)) - source_color;
case GPU::BlendFactor::SrcAlpha:
return to_vec4(source_color.w());
case GPU::BlendFactor::SrcAlphaSaturate: {
auto saturated = min(source_color.w(), 1.f - destination_color.w());
return { saturated, saturated, saturated, expand4(1.f) };
}
case GPU::BlendFactor::SrcColor:
return source_color;
case GPU::BlendFactor::Zero:
return to_vec4(expand4(0.f));
default:
VERIFY_NOT_REACHED();
}
}
// OpenGL 2.0 § 4.1.8, table 4.1
ALWAYS_INLINE static Vector4<f32x4> blend_colors(
GPU::BlendEquation rgb_mode,
GPU::BlendEquation alpha_mode,
Vector4<f32x4> const& source,
Vector4<f32x4> const& source_weights,
Vector4<f32x4> const& destination,
Vector4<f32x4> const& destination_weights)
{
auto apply_equation = [&](GPU::BlendEquation mode, auto source, auto source_weights, auto destination, auto destination_weights) -> auto {
switch (mode) {
case GPU::BlendEquation::Add:
return source * source_weights + destination * destination_weights;
case GPU::BlendEquation::Subtract:
return source * source_weights - destination * destination_weights;
case GPU::BlendEquation::ReverseSubtract:
return destination * source_weights - source * destination_weights;
case GPU::BlendEquation::Min:
return AK::min(source, destination);
case GPU::BlendEquation::Max:
return AK::max(source, destination);
default:
VERIFY_NOT_REACHED();
}
};
// Single calculation if RGB mode is the same as the alpha mode
if (rgb_mode == alpha_mode)
return apply_equation(rgb_mode, source, source_weights, destination, destination_weights);
// Split RGB/alpha calculation
auto rgb = apply_equation(rgb_mode, source.xyz(), source_weights.xyz(), destination.xyz(), destination_weights.xyz());
auto alpha = apply_equation(alpha_mode, source.w(), source_weights.w(), destination.w(), destination_weights.w());
return { rgb.x(), rgb.y(), rgb.z(), alpha };
}
template<typename CB1, typename CB2, typename CB3>
ALWAYS_INLINE void Device::rasterize(Gfx::IntRect& render_bounds, CB1 set_coverage_mask, CB2 set_quad_depth, CB3 set_quad_attributes)
{
// Return if alpha testing is a no-op
if (m_options.enable_alpha_test && m_options.alpha_test_func == GPU::AlphaTestFunction::Never)
return;
auto const alpha_test_ref_value = expand4(m_options.alpha_test_ref_value);
// Buffers
auto color_buffer = m_frame_buffer->color_buffer();
auto depth_buffer = m_frame_buffer->depth_buffer();
auto stencil_buffer = m_frame_buffer->stencil_buffer();
// Stencil configuration and writing
auto const& stencil_configuration = m_stencil_configuration[GPU::Face::Front];
auto const stencil_reference_value = stencil_configuration.reference_value & stencil_configuration.test_mask;
auto write_to_stencil = [](GPU::StencilType* stencil_ptrs[4], i32x4 stencil_value, GPU::StencilOperation op, GPU::StencilType reference_value, GPU::StencilType write_mask, i32x4 pixel_mask) {
if (write_mask == 0 || op == GPU::StencilOperation::Keep)
return;
switch (op) {
case GPU::StencilOperation::Decrement:
stencil_value = (stencil_value & ~write_mask) | (max(stencil_value - 1, expand4(0)) & write_mask);
break;
case GPU::StencilOperation::DecrementWrap:
stencil_value = (stencil_value & ~write_mask) | (((stencil_value - 1) & 0xFF) & write_mask);
break;
case GPU::StencilOperation::Increment:
stencil_value = (stencil_value & ~write_mask) | (min(stencil_value + 1, expand4(0xFF)) & write_mask);
break;
case GPU::StencilOperation::IncrementWrap:
stencil_value = (stencil_value & ~write_mask) | (((stencil_value + 1) & 0xFF) & write_mask);
break;
case GPU::StencilOperation::Invert:
stencil_value ^= write_mask;
break;
case GPU::StencilOperation::Replace:
stencil_value = (stencil_value & ~write_mask) | (reference_value & write_mask);
break;
case GPU::StencilOperation::Zero:
stencil_value &= ~write_mask;
break;
default:
VERIFY_NOT_REACHED();
}
INCREASE_STATISTICS_COUNTER(g_num_stencil_writes, maskcount(pixel_mask));
store4_masked(stencil_value, stencil_ptrs[0], stencil_ptrs[1], stencil_ptrs[2], stencil_ptrs[3], pixel_mask);
};
// Limit rendering to framebuffer and scissor rects
render_bounds.intersect(m_frame_buffer->rect());
if (m_options.scissor_enabled)
render_bounds.intersect(m_options.scissor_box);
// Quad bounds
auto const render_bounds_left = render_bounds.left();
auto const render_bounds_right = render_bounds.right() - 1;
auto const render_bounds_top = render_bounds.top();
auto const render_bounds_bottom = render_bounds.bottom() - 1;
auto const qx0 = render_bounds_left & ~1;
auto const qx1 = render_bounds_right & ~1;
auto const qy0 = render_bounds_top & ~1;
auto const qy1 = render_bounds_bottom & ~1;
// Blend weights
Vector4<f32x4> source_weights;
Vector4<f32x4> destination_weights;
auto const source_weights_are_constant = is_blend_factor_constant(m_options.blend_source_factor);
auto const destination_weights_are_constant = is_blend_factor_constant(m_options.blend_destination_factor);
if (m_options.enable_blending) {
if (source_weights_are_constant)
source_weights = get_blend_factor(m_options.blend_source_factor, {}, {});
if (destination_weights_are_constant)
destination_weights = get_blend_factor(m_options.blend_destination_factor, {}, {});
}
// Rasterize all quads
// FIXME: this could be embarrassingly parallel
for (int qy = qy0; qy <= qy1; qy += 2) {
for (int qx = qx0; qx <= qx1; qx += 2) {
PixelQuad quad;
quad.screen_coordinates = {
i32x4 { qx, qx + 1, qx, qx + 1 },
i32x4 { qy, qy, qy + 1, qy + 1 },
};
// Set coverage mask and test against render bounds
set_coverage_mask(quad);
quad.mask &= quad.screen_coordinates.x() >= render_bounds_left
&& quad.screen_coordinates.x() <= render_bounds_right
&& quad.screen_coordinates.y() >= render_bounds_top
&& quad.screen_coordinates.y() <= render_bounds_bottom;
auto coverage_bits = maskbits(quad.mask);
if (coverage_bits == 0)
continue;
INCREASE_STATISTICS_COUNTER(g_num_quads, 1);
INCREASE_STATISTICS_COUNTER(g_num_pixels, maskcount(quad.mask));
// Stencil testing
GPU::StencilType* stencil_ptrs[4];
i32x4 stencil_value;
if (m_options.enable_stencil_test) {
stencil_ptrs[0] = coverage_bits & 1 ? &stencil_buffer->scanline(qy)[qx] : nullptr;
stencil_ptrs[1] = coverage_bits & 2 ? &stencil_buffer->scanline(qy)[qx + 1] : nullptr;
stencil_ptrs[2] = coverage_bits & 4 ? &stencil_buffer->scanline(qy + 1)[qx] : nullptr;
stencil_ptrs[3] = coverage_bits & 8 ? &stencil_buffer->scanline(qy + 1)[qx + 1] : nullptr;
stencil_value = load4_masked(stencil_ptrs[0], stencil_ptrs[1], stencil_ptrs[2], stencil_ptrs[3], quad.mask);
stencil_value &= stencil_configuration.test_mask;
i32x4 stencil_test_passed;
switch (stencil_configuration.test_function) {
case GPU::StencilTestFunction::Always:
stencil_test_passed = expand4(~0);
break;
case GPU::StencilTestFunction::Equal:
stencil_test_passed = stencil_value == stencil_reference_value;
break;
case GPU::StencilTestFunction::Greater:
stencil_test_passed = stencil_value > stencil_reference_value;
break;
case GPU::StencilTestFunction::GreaterOrEqual:
stencil_test_passed = stencil_value >= stencil_reference_value;
break;
case GPU::StencilTestFunction::Less:
stencil_test_passed = stencil_value < stencil_reference_value;
break;
case GPU::StencilTestFunction::LessOrEqual:
stencil_test_passed = stencil_value <= stencil_reference_value;
break;
case GPU::StencilTestFunction::Never:
stencil_test_passed = expand4(0);
break;
case GPU::StencilTestFunction::NotEqual:
stencil_test_passed = stencil_value != stencil_reference_value;
break;
default:
VERIFY_NOT_REACHED();
}
// Update stencil buffer for pixels that failed the stencil test
write_to_stencil(
stencil_ptrs,
stencil_value,
stencil_configuration.on_stencil_test_fail,
stencil_reference_value,
stencil_configuration.write_mask,
quad.mask & ~stencil_test_passed);
// Update coverage mask + early quad rejection
quad.mask &= stencil_test_passed;
coverage_bits = maskbits(quad.mask);
if (coverage_bits == 0)
continue;
}
// Depth testing
GPU::DepthType* depth_ptrs[4] = {
coverage_bits & 1 ? &depth_buffer->scanline(qy)[qx] : nullptr,
coverage_bits & 2 ? &depth_buffer->scanline(qy)[qx + 1] : nullptr,
coverage_bits & 4 ? &depth_buffer->scanline(qy + 1)[qx] : nullptr,
coverage_bits & 8 ? &depth_buffer->scanline(qy + 1)[qx + 1] : nullptr,
};
if (m_options.enable_depth_test) {
set_quad_depth(quad);
auto depth = load4_masked(depth_ptrs[0], depth_ptrs[1], depth_ptrs[2], depth_ptrs[3], quad.mask);
i32x4 depth_test_passed;
switch (m_options.depth_func) {
case GPU::DepthTestFunction::Always:
depth_test_passed = expand4(~0);
break;
case GPU::DepthTestFunction::Never:
depth_test_passed = expand4(0);
break;
case GPU::DepthTestFunction::Greater:
depth_test_passed = quad.depth > depth;
break;
case GPU::DepthTestFunction::GreaterOrEqual:
depth_test_passed = quad.depth >= depth;
break;
case GPU::DepthTestFunction::NotEqual:
depth_test_passed = quad.depth != depth;
break;
case GPU::DepthTestFunction::Equal:
depth_test_passed = quad.depth == depth;
break;
case GPU::DepthTestFunction::LessOrEqual:
depth_test_passed = quad.depth <= depth;
break;
case GPU::DepthTestFunction::Less:
depth_test_passed = quad.depth < depth;
break;
default:
VERIFY_NOT_REACHED();
}
// Update stencil buffer for pixels that failed the depth test
if (m_options.enable_stencil_test) {
write_to_stencil(
stencil_ptrs,
stencil_value,
stencil_configuration.on_depth_test_fail,
stencil_reference_value,
stencil_configuration.write_mask,
quad.mask & ~depth_test_passed);
}
// Update coverage mask + early quad rejection
quad.mask &= depth_test_passed;
coverage_bits = maskbits(quad.mask);
if (coverage_bits == 0)
continue;
}
// Update stencil buffer for passed pixels
if (m_options.enable_stencil_test) {
write_to_stencil(
stencil_ptrs,
stencil_value,
stencil_configuration.on_pass,
stencil_reference_value,
stencil_configuration.write_mask,
quad.mask);
}
INCREASE_STATISTICS_COUNTER(g_num_pixels_shaded, maskcount(quad.mask));
set_quad_attributes(quad);
shade_fragments(quad);
// Alpha testing
if (m_options.enable_alpha_test) {
test_alpha(quad, m_options.alpha_test_func, alpha_test_ref_value);
coverage_bits = maskbits(quad.mask);
if (coverage_bits == 0)
continue;
}
// Write to depth buffer
if (m_options.enable_depth_test && m_options.enable_depth_write)
store4_masked(quad.depth, depth_ptrs[0], depth_ptrs[1], depth_ptrs[2], depth_ptrs[3], quad.mask);
// We will not update the color buffer at all
if ((m_options.color_mask == 0) || !m_options.enable_color_write)
continue;
GPU::ColorType* color_ptrs[4] = {
coverage_bits & 1 ? &color_buffer->scanline(qy)[qx] : nullptr,
coverage_bits & 2 ? &color_buffer->scanline(qy)[qx + 1] : nullptr,
coverage_bits & 4 ? &color_buffer->scanline(qy + 1)[qx] : nullptr,
coverage_bits & 8 ? &color_buffer->scanline(qy + 1)[qx + 1] : nullptr,
};
u32x4 dst_u32;
if (m_options.enable_blending || m_options.color_mask != 0xffffffff)
dst_u32 = load4_masked(color_ptrs[0], color_ptrs[1], color_ptrs[2], color_ptrs[3], quad.mask);
auto out_color = quad.get_output_vector4(SHADER_OUTPUT_FIRST_COLOR);
// Blend color values from pixel_staging into color_buffer
if (m_options.enable_blending) {
INCREASE_STATISTICS_COUNTER(g_num_pixels_blended, maskcount(quad.mask));
auto const& source_color = out_color;
auto const destination_color = to_vec4(dst_u32);
if (!source_weights_are_constant)
source_weights = get_blend_factor(m_options.blend_source_factor, source_color, destination_color);
if (!destination_weights_are_constant)
destination_weights = get_blend_factor(m_options.blend_destination_factor, source_color, destination_color);
out_color = blend_colors(m_options.blend_equation_rgb, m_options.blend_equation_alpha, source_color, source_weights, destination_color, destination_weights);
}
auto const argb32_color = to_argb32(out_color);
if (m_options.color_mask == 0xffffffff)
store4_masked(argb32_color, color_ptrs[0], color_ptrs[1], color_ptrs[2], color_ptrs[3], quad.mask);
else
store4_masked((argb32_color & m_options.color_mask) | (dst_u32 & ~m_options.color_mask), color_ptrs[0], color_ptrs[1], color_ptrs[2], color_ptrs[3], quad.mask);
}
}
}
void Device::rasterize_line_aliased(GPU::Vertex& from, GPU::Vertex& to)
{
// FIXME: implement aliased lines; for now we fall back to anti-aliased logic
rasterize_line_antialiased(from, to);
}
void Device::rasterize_line_antialiased(GPU::Vertex& from, GPU::Vertex& to)
{
auto const from_coords = from.window_coordinates.xy();
auto const to_coords = to.window_coordinates.xy();
auto const line_width = ceilf(m_options.line_width);
auto const line_radius = line_width / 2;
auto render_bounds = Gfx::IntRect {
min(from_coords.x(), to_coords.x()),
min(from_coords.y(), to_coords.y()),
abs(from_coords.x() - to_coords.x()) + 1,
abs(from_coords.y() - to_coords.y()) + 1,
};
render_bounds.inflate(line_width, line_width);
auto const from_coords4 = expand4(from_coords);
auto const line_vector = to_coords - from_coords;
auto const line_vector4 = expand4(line_vector);
auto const line_dot4 = expand4(line_vector.dot(line_vector));
auto const from_depth4 = expand4(from.window_coordinates.z());
auto const to_depth4 = expand4(to.window_coordinates.z());
auto const from_color4 = expand4(from.color);
auto const from_fog_depth4 = expand4(abs(from.eye_coordinates.z()));
// Rasterize using a 2D signed distance field for a line segment
// FIXME: performance-wise, this might be the absolute worst way to draw an anti-aliased line
f32x4 distance_along_line;
rasterize(
render_bounds,
[&from_coords4, &distance_along_line, &line_vector4, &line_dot4, &line_radius](auto& quad) {
auto const screen_coordinates4 = to_vec2_f32x4(quad.screen_coordinates);
auto const pixel_vector = screen_coordinates4 - from_coords4;
distance_along_line = AK::SIMD::clamp(pixel_vector.dot(line_vector4) / line_dot4, 0.f, 1.f);
auto distance_to_line = length(pixel_vector - line_vector4 * distance_along_line) - line_radius;
// Add .5f to the distance so coverage transitions half a pixel before the actual border
quad.coverage = 1.f - AK::SIMD::clamp(distance_to_line + 0.5f, 0.f, 1.f);
quad.mask = quad.coverage > 0.f;
},
[&from_depth4, &to_depth4, &distance_along_line](auto& quad) {
quad.depth = mix(from_depth4, to_depth4, distance_along_line);
},
[&from_color4, &from, &from_fog_depth4](auto& quad) {
// FIXME: interpolate color, tex coords and fog depth along the distance of the line
// in clip space (i.e. NOT distance_from_line)
quad.set_input(SHADER_INPUT_VERTEX_COLOR, from_color4);
for (size_t i = 0; i < GPU::NUM_TEXTURE_UNITS; ++i)
quad.set_input(SHADER_INPUT_FIRST_TEXCOORD + i * 4, expand4(from.tex_coords[i]));
quad.fog_depth = from_fog_depth4;
});
}
void Device::rasterize_line(GPU::Vertex& from, GPU::Vertex& to)
{
if (m_options.line_smooth)
rasterize_line_antialiased(from, to);
else
rasterize_line_aliased(from, to);
}
void Device::rasterize_point_aliased(GPU::Vertex& point)
{
// Determine aliased point width
constexpr size_t maximum_aliased_point_size = 64;
auto point_width = clamp(round_to<int>(m_options.point_size), 1, maximum_aliased_point_size);
// Determine aliased center coordinates
IntVector2 point_center;
if (point_width % 2 == 1)
point_center = point.window_coordinates.xy().to_type<int>();
else
point_center = (point.window_coordinates.xy() + FloatVector2 { .5f, .5f }).to_type<int>();
// Aliased points are rects; calculate boundaries around center
auto point_rect = Gfx::IntRect {
point_center.x() - point_width / 2,
point_center.y() - point_width / 2,
point_width,
point_width,
};
// Rasterize the point as a rect
rasterize(
point_rect,
[](auto& quad) {
// We already passed in point_rect, so this doesn't matter
quad.mask = expand4(~0);
},
[&point](auto& quad) {
quad.depth = expand4(point.window_coordinates.z());
},
[&point](auto& quad) {
quad.set_input(SHADER_INPUT_VERTEX_COLOR, expand4(point.color));
for (size_t i = 0; i < GPU::NUM_TEXTURE_UNITS; ++i)
quad.set_input(SHADER_INPUT_FIRST_TEXCOORD + i * 4, expand4(point.tex_coords[i]));
quad.fog_depth = expand4(abs(point.eye_coordinates.z()));
});
}
void Device::rasterize_point_antialiased(GPU::Vertex& point)
{
auto const center = point.window_coordinates.xy();
auto const center4 = expand4(center);
auto const radius = m_options.point_size / 2;
auto render_bounds = Gfx::IntRect {
center.x() - radius,
center.y() - radius,
radius * 2 + 1,
radius * 2 + 1,
};
// Rasterize using a 2D signed distance field for a circle
rasterize(
render_bounds,
[&center4, &radius](auto& quad) {
auto screen_coords = to_vec2_f32x4(quad.screen_coordinates);
auto distance_to_point = length(center4 - screen_coords) - radius;
// Add .5f to the distance so coverage transitions half a pixel before the actual border
quad.coverage = 1.f - AK::SIMD::clamp(distance_to_point + .5f, 0.f, 1.f);
quad.mask = quad.coverage > 0.f;
},
[&point](auto& quad) {
quad.depth = expand4(point.window_coordinates.z());
},
[&point](auto& quad) {
quad.set_input(SHADER_INPUT_VERTEX_COLOR, expand4(point.color));
for (size_t i = 0; i < GPU::NUM_TEXTURE_UNITS; ++i)
quad.set_input(SHADER_INPUT_FIRST_TEXCOORD + i * 4, expand4(point.tex_coords[i]));
quad.fog_depth = expand4(abs(point.eye_coordinates.z()));
});
}
void Device::rasterize_point(GPU::Vertex& point)
{
if (m_options.point_smooth)
rasterize_point_antialiased(point);
else
rasterize_point_aliased(point);
}
void Device::rasterize_triangle(Triangle& triangle)
{
INCREASE_STATISTICS_COUNTER(g_num_rasterized_triangles, 1);
auto v0 = (triangle.vertices[0].window_coordinates.xy() * subpixel_factor).to_rounded<int>();
auto v1 = (triangle.vertices[1].window_coordinates.xy() * subpixel_factor).to_rounded<int>();
auto v2 = (triangle.vertices[2].window_coordinates.xy() * subpixel_factor).to_rounded<int>();
auto triangle_area = edge_function(v0, v1, v2);
if (triangle_area == 0)
return;
// Perform face culling
if (m_options.enable_culling) {
bool is_front = (m_options.front_face == GPU::WindingOrder::CounterClockwise ? triangle_area > 0 : triangle_area < 0);
if (!is_front && m_options.cull_back)
return;
if (is_front && m_options.cull_front)
return;
}
// Force counter-clockwise ordering of vertices
if (triangle_area < 0) {
swap(triangle.vertices[0], triangle.vertices[1]);
swap(v0, v1);
triangle_area *= -1;
}
auto const& vertex0 = triangle.vertices[0];
auto const& vertex1 = triangle.vertices[1];
auto const& vertex2 = triangle.vertices[2];
auto const one_over_area = 1.0f / triangle_area;
// This function calculates the 3 edge values for the pixel relative to the triangle.
auto calculate_edge_values4 = [v0, v1, v2](Vector2<i32x4> const& p) -> Vector3<i32x4> {
return {
edge_function4(v1, v2, p),
edge_function4(v2, v0, p),
edge_function4(v0, v1, p),
};
};
// Zero is used in testing against edge values below, applying the "top-left rule". If a pixel
// lies exactly on an edge shared by two triangles, we only render that pixel if the edge in
// question is a "top" or "left" edge. By setting either a 1 or 0, we effectively change the
// comparisons against the edge values below from "> 0" into ">= 0".
IntVector3 const zero {
(v2.y() < v1.y() || (v2.y() == v1.y() && v2.x() < v1.x())) ? 0 : 1,
(v0.y() < v2.y() || (v0.y() == v2.y() && v0.x() < v2.x())) ? 0 : 1,
(v1.y() < v0.y() || (v1.y() == v0.y() && v1.x() < v0.x())) ? 0 : 1,
};
// This function tests whether a point as identified by its 3 edge values lies within the triangle
auto test_point4 = [zero](Vector3<i32x4> const& edges) -> i32x4 {
return edges.x() >= zero.x()
&& edges.y() >= zero.y()
&& edges.z() >= zero.z();
};
// Calculate render bounds based on the triangle's vertices
Gfx::IntRect render_bounds;
render_bounds.set_left(min(min(v0.x(), v1.x()), v2.x()) / subpixel_factor);
render_bounds.set_right(max(max(v0.x(), v1.x()), v2.x()) / subpixel_factor + 1);
render_bounds.set_top(min(min(v0.y(), v1.y()), v2.y()) / subpixel_factor);
render_bounds.set_bottom(max(max(v0.y(), v1.y()), v2.y()) / subpixel_factor + 1);
// Calculate depth of fragment for fog;
// OpenGL 1.5 chapter 3.10: "An implementation may choose to approximate the
// eye-coordinate distance from the eye to each fragment center by |Ze|."
Vector3<f32x4> fog_depth;
if (m_options.fog_enabled) {
fog_depth = {
expand4(abs(vertex0.eye_coordinates.z())),
expand4(abs(vertex1.eye_coordinates.z())),
expand4(abs(vertex2.eye_coordinates.z())),
};
}
auto const half_pixel_offset = Vector2<i32x4> { expand4(subpixel_factor / 2), expand4(subpixel_factor / 2) };
auto const window_w_coordinates = Vector3<f32x4> {
expand4(vertex0.window_coordinates.w()),
expand4(vertex1.window_coordinates.w()),
expand4(vertex2.window_coordinates.w()),
};
// Calculate depth offset to apply
float depth_offset = 0.f;
if (m_options.depth_offset_enabled) {
// OpenGL 2.0 § 3.5.5 allows us to approximate the maximum slope
auto delta_z = max(
max(
abs(vertex0.window_coordinates.z() - vertex1.window_coordinates.z()),
abs(vertex1.window_coordinates.z() - vertex2.window_coordinates.z())),
abs(vertex2.window_coordinates.z() - vertex0.window_coordinates.z()));
auto depth_max_slope = max(delta_z / render_bounds.width(), delta_z / render_bounds.height());
// Calculate total depth offset
depth_offset = depth_max_slope * m_options.depth_offset_factor + NumericLimits<float>::epsilon() * m_options.depth_offset_constant;
}
auto const window_z_coordinates = Vector3<f32x4> {
expand4(vertex0.window_coordinates.z() + depth_offset),
expand4(vertex1.window_coordinates.z() + depth_offset),
expand4(vertex2.window_coordinates.z() + depth_offset),
};
rasterize(
render_bounds,
[&](auto& quad) {
auto edge_values = calculate_edge_values4(quad.screen_coordinates * subpixel_factor + half_pixel_offset);
quad.mask = test_point4(edge_values);
quad.barycentrics = {
to_f32x4(edge_values.x()),
to_f32x4(edge_values.y()),
to_f32x4(edge_values.z()),
};
},
[&](auto& quad) {
// Determine each edge's ratio to the total area
quad.barycentrics = quad.barycentrics * one_over_area;
// Because the Z coordinates were divided by W, we can interpolate between them
quad.depth = AK::SIMD::clamp(window_z_coordinates.dot(quad.barycentrics), 0.f, 1.f);
},
[&](auto& quad) {
auto const interpolated_reciprocal_w = window_w_coordinates.dot(quad.barycentrics);
quad.barycentrics = quad.barycentrics * window_w_coordinates / interpolated_reciprocal_w;
// FIXME: make this more generic. We want to interpolate more than just color and uv
if (m_options.shade_smooth)
quad.set_input(SHADER_INPUT_VERTEX_COLOR, interpolate(expand4(vertex0.color), expand4(vertex1.color), expand4(vertex2.color), quad.barycentrics));
else
quad.set_input(SHADER_INPUT_VERTEX_COLOR, expand4(vertex0.color));
for (GPU::TextureUnitIndex i = 0; i < GPU::NUM_TEXTURE_UNITS; ++i)
quad.set_input(SHADER_INPUT_FIRST_TEXCOORD + i * 4, interpolate(expand4(vertex0.tex_coords[i]), expand4(vertex1.tex_coords[i]), expand4(vertex2.tex_coords[i]), quad.barycentrics));
if (m_options.fog_enabled)
quad.fog_depth = fog_depth.dot(quad.barycentrics);
});
}
Device::Device(Gfx::IntSize size)
: m_frame_buffer(FrameBuffer<GPU::ColorType, GPU::DepthType, GPU::StencilType>::try_create(size).release_value_but_fixme_should_propagate_errors())
, m_shader_processor(m_samplers)
{
m_options.scissor_box = m_frame_buffer->rect();
m_options.viewport = m_frame_buffer->rect();
// Ensure we can always append 3 vertices unchecked
m_clipped_vertices.ensure_capacity(3);
}
GPU::DeviceInfo Device::info() const
{
return {
.vendor_name = "SerenityOS",
.device_name = "SoftGPU",
.num_texture_units = GPU::NUM_TEXTURE_UNITS,
.num_lights = NUM_LIGHTS,
.max_clip_planes = MAX_CLIP_PLANES,
.max_texture_size = MAX_TEXTURE_SIZE,
.max_texture_lod_bias = MAX_TEXTURE_LOD_BIAS,
.stencil_bits = sizeof(GPU::StencilType) * 8,
.supports_npot_textures = true,
.supports_texture_clamp_to_edge = true,
.supports_texture_env_add = true,
};
}
static void generate_texture_coordinates(GPU::Vertex const& vertex, FloatVector4& tex_coord, GPU::TextureUnitConfiguration const& texture_unit_configuration)
{
auto generate_coordinate = [&](size_t config_index) -> float {
auto const& tex_coord_generation = texture_unit_configuration.tex_coord_generation[config_index];
switch (tex_coord_generation.mode) {
case GPU::TexCoordGenerationMode::ObjectLinear: {
auto coefficients = tex_coord_generation.coefficients;
return coefficients.dot(vertex.position);
}
case GPU::TexCoordGenerationMode::EyeLinear: {
auto coefficients = tex_coord_generation.coefficients;
return coefficients.dot(vertex.eye_coordinates);
}
case GPU::TexCoordGenerationMode::SphereMap: {
auto const eye_unit = vertex.eye_coordinates.normalized();
FloatVector3 const eye_unit_xyz = eye_unit.xyz();
auto const normal = vertex.normal;
auto reflection = eye_unit_xyz - normal * 2 * normal.dot(eye_unit_xyz);
reflection.set_z(reflection.z() + 1);
auto const reflection_value = reflection[config_index];
return reflection_value / (2 * reflection.length()) + 0.5f;
}
case GPU::TexCoordGenerationMode::ReflectionMap: {
auto const eye_unit = vertex.eye_coordinates.normalized();
FloatVector3 const eye_unit_xyz = eye_unit.xyz();
auto const normal = vertex.normal;
auto reflection = eye_unit_xyz - normal * 2 * normal.dot(eye_unit_xyz);
return reflection[config_index];
}
case GPU::TexCoordGenerationMode::NormalMap: {
return vertex.normal[config_index];
}
}
VERIFY_NOT_REACHED();
};
auto const enabled_coords = texture_unit_configuration.tex_coord_generation_enabled;
if (enabled_coords == GPU::TexCoordGenerationCoordinate::None)
return;
tex_coord = {
((enabled_coords & GPU::TexCoordGenerationCoordinate::S) > 0) ? generate_coordinate(0) : tex_coord.x(),
((enabled_coords & GPU::TexCoordGenerationCoordinate::T) > 0) ? generate_coordinate(1) : tex_coord.y(),
((enabled_coords & GPU::TexCoordGenerationCoordinate::R) > 0) ? generate_coordinate(2) : tex_coord.z(),
((enabled_coords & GPU::TexCoordGenerationCoordinate::Q) > 0) ? generate_coordinate(3) : tex_coord.w(),
};
}
void Device::calculate_vertex_lighting(GPU::Vertex& vertex) const
{
if (!m_options.lighting_enabled)
return;
auto const& material = m_materials.at(0);
auto ambient = material.ambient;
auto diffuse = material.diffuse;
auto emissive = material.emissive;
auto specular = material.specular;
if (m_options.color_material_enabled
&& (m_options.color_material_face == GPU::ColorMaterialFace::Front || m_options.color_material_face == GPU::ColorMaterialFace::FrontAndBack)) {
switch (m_options.color_material_mode) {
case GPU::ColorMaterialMode::Ambient:
ambient = vertex.color;
break;
case GPU::ColorMaterialMode::AmbientAndDiffuse:
ambient = vertex.color;
diffuse = vertex.color;
break;
case GPU::ColorMaterialMode::Diffuse:
diffuse = vertex.color;
break;
case GPU::ColorMaterialMode::Emissive:
emissive = vertex.color;
break;
case GPU::ColorMaterialMode::Specular:
specular = vertex.color;
break;
}
}
FloatVector4 result_color = emissive + ambient * m_lighting_model.scene_ambient_color;
for (auto const& light : m_lights) {
if (!light.is_enabled)
continue;
// We need to save the length here because the attenuation factor requires a non-normalized vector!
auto sgi_arrow_operator = [](FloatVector4 const& p1, FloatVector4 const& p2, float& output_length) {
FloatVector3 light_vector;
if ((p1.w() != 0.f) && (p2.w() == 0.f))
light_vector = p2.xyz();
else if ((p1.w() == 0.f) && (p2.w() != 0.f))
light_vector = -p1.xyz();
else
light_vector = p2.xyz() - p1.xyz();
output_length = light_vector.length();
if (output_length == 0.f)
return light_vector;
return light_vector / output_length;
};
auto sgi_dot_operator = [](FloatVector3 const& d1, FloatVector3 const& d2) {
return AK::max(d1.dot(d2), 0.0f);
};
float vertex_to_light_length = 0.f;
FloatVector3 vertex_to_light = sgi_arrow_operator(vertex.eye_coordinates, light.position, vertex_to_light_length);
// Light attenuation value.
float light_attenuation_factor = 1.0f;
if (light.position.w() != 0.0f)
light_attenuation_factor = 1.0f / (light.constant_attenuation + (light.linear_attenuation * vertex_to_light_length) + (light.quadratic_attenuation * vertex_to_light_length * vertex_to_light_length));
// Spotlight factor
float spotlight_factor = 1.0f;
if (light.spotlight_cutoff_angle != 180.0f) {
auto const vertex_to_light_dot_spotlight_direction = sgi_dot_operator(vertex_to_light, light.spotlight_direction.normalized());
auto const cos_spotlight_cutoff = AK::cos<float>(AK::to_radians(light.spotlight_cutoff_angle));
if (vertex_to_light_dot_spotlight_direction >= cos_spotlight_cutoff)
spotlight_factor = AK::pow<float>(vertex_to_light_dot_spotlight_direction, light.spotlight_exponent);
else
spotlight_factor = 0.0f;
}
// FIXME: The spec allows for splitting the colors calculated here into multiple different colors (primary/secondary color). Investigate what this means.
(void)m_lighting_model.color_control;
// FIXME: Two sided lighting should be implemented eventually (I believe this is where the normals are -ve and then lighting is calculated with the BACK material)
(void)m_lighting_model.two_sided_lighting;
// Ambient
auto const ambient_component = ambient * light.ambient_intensity;
// Diffuse
auto const normal_dot_vertex_to_light = sgi_dot_operator(vertex.normal, vertex_to_light);
auto const diffuse_component = diffuse * light.diffuse_intensity * normal_dot_vertex_to_light;
// Specular
FloatVector4 specular_component = { 0.0f, 0.0f, 0.0f, 0.0f };
if (normal_dot_vertex_to_light > 0.0f) {
FloatVector3 half_vector_normalized;
if (!m_lighting_model.viewer_at_infinity) {
half_vector_normalized = vertex_to_light + FloatVector3(0.0f, 0.0f, 1.0f);
} else {
auto const vertex_to_eye_point = sgi_arrow_operator(vertex.eye_coordinates, { 0.f, 0.f, 0.f, 1.f }, vertex_to_light_length);
half_vector_normalized = vertex_to_light + vertex_to_eye_point;
}
half_vector_normalized.normalize();
auto const normal_dot_half_vector = sgi_dot_operator(vertex.normal, half_vector_normalized);
auto const specular_coefficient = AK::pow(normal_dot_half_vector, material.shininess);
specular_component = specular * light.specular_intensity * specular_coefficient;
}
auto color = ambient_component + diffuse_component + specular_component;
color = color * light_attenuation_factor * spotlight_factor;
result_color += color;
}
vertex.color = result_color;
vertex.color.set_w(diffuse.w()); // OpenGL 1.5 spec, page 59: "The A produced by lighting is the alpha value associated with diffuse color material"
vertex.color.clamp(0.0f, 1.0f);
}
void Device::draw_primitives(GPU::PrimitiveType primitive_type, Vector<GPU::Vertex>& vertices)
{
// At this point, the user has effectively specified that they are done with defining the geometry
// of what they want to draw. We now need to do a few things (https://www.khronos.org/opengl/wiki/Rendering_Pipeline_Overview):
//
// 1. Transform all of the vertices in the current vertex list into eye space by multiplying the model-view matrix
// 2. Transform all of the vertices from eye space into clip space by multiplying by the projection matrix
// 3. If culling is enabled, we cull the desired faces (https://learnopengl.com/Advanced-OpenGL/Face-culling)
// 4. Each element of the vertex is then divided by w to bring the positions into NDC (Normalized Device Coordinates)
// 5. The triangle's vertices are sorted in a counter-clockwise orientation
// 6. The triangles are then sent off to the rasterizer and drawn to the screen
if (vertices.is_empty())
return;
// First, transform all vertices
for (auto& vertex : vertices) {
vertex.eye_coordinates = m_model_view_transform * vertex.position;
vertex.normal = m_normal_transform * vertex.normal;
if (m_options.normalization_enabled)
vertex.normal.normalize();
calculate_vertex_lighting(vertex);
vertex.clip_coordinates = m_projection_transform * vertex.eye_coordinates;
for (GPU::TextureUnitIndex i = 0; i < GPU::NUM_TEXTURE_UNITS; ++i) {
auto const& texture_unit_configuration = m_texture_unit_configuration[i];
if (!texture_unit_configuration.enabled)
continue;
generate_texture_coordinates(vertex, vertex.tex_coords[i], texture_unit_configuration);
vertex.tex_coords[i] = texture_unit_configuration.transformation_matrix * vertex.tex_coords[i];
}
}
// Window coordinate calculation
auto const viewport = m_options.viewport;
auto const viewport_half_width = viewport.width() / 2.f;
auto const viewport_half_height = viewport.height() / 2.f;
auto const viewport_center_x = viewport.x() + viewport_half_width;
auto const viewport_center_y = viewport.y() + viewport_half_height;
auto const depth_half_range = (m_options.depth_max - m_options.depth_min) / 2;
auto const depth_halfway = (m_options.depth_min + m_options.depth_max) / 2;
auto calculate_vertex_window_coordinates = [&](GPU::Vertex& vertex) {
auto const one_over_w = 1 / vertex.clip_coordinates.w();
auto const ndc_coordinates = vertex.clip_coordinates.xyz() * one_over_w;
vertex.window_coordinates = {
viewport_center_x + ndc_coordinates.x() * viewport_half_width,
viewport_center_y + ndc_coordinates.y() * viewport_half_height,
depth_halfway + ndc_coordinates.z() * depth_half_range,
one_over_w,
};
};
// Process points
if (primitive_type == GPU::PrimitiveType::Points) {
m_clipper.clip_points_against_frustum(vertices);
for (auto& vertex : vertices) {
calculate_vertex_window_coordinates(vertex);
rasterize_point(vertex);
}
return;
}
// Process lines, line loop and line strips
auto rasterize_line_segment = [&](GPU::Vertex& from, GPU::Vertex& to) {
if (!m_clipper.clip_line_against_frustum(from, to))
return;
calculate_vertex_window_coordinates(from);
calculate_vertex_window_coordinates(to);
rasterize_line(from, to);
};
if (primitive_type == GPU::PrimitiveType::Lines) {
if (vertices.size() < 2)
return;
for (size_t i = 0; i < vertices.size() - 1; i += 2)
rasterize_line_segment(vertices[i], vertices[i + 1]);
return;
} else if (primitive_type == GPU::PrimitiveType::LineLoop) {
if (vertices.size() < 2)
return;
for (size_t i = 0; i < vertices.size(); ++i)
rasterize_line_segment(vertices[i], vertices[(i + 1) % vertices.size()]);
return;
} else if (primitive_type == GPU::PrimitiveType::LineStrip) {
if (vertices.size() < 2)
return;
for (size_t i = 0; i < vertices.size() - 1; ++i)
rasterize_line_segment(vertices[i], vertices[i + 1]);
return;
}
// Let's construct some triangles
m_triangle_list.clear_with_capacity();
m_processed_triangles.clear_with_capacity();
if (primitive_type == GPU::PrimitiveType::Triangles) {
Triangle triangle;
if (vertices.size() < 3)
return;
for (size_t i = 0; i < vertices.size() - 2; i += 3) {
triangle.vertices[0] = vertices.at(i);
triangle.vertices[1] = vertices.at(i + 1);
triangle.vertices[2] = vertices.at(i + 2);
m_triangle_list.append(triangle);
}
} else if (primitive_type == GPU::PrimitiveType::Quads) {
// We need to construct two triangles to form the quad
Triangle triangle;
if (vertices.size() < 4)
return;
for (size_t i = 0; i < vertices.size() - 3; i += 4) {
// Triangle 1
triangle.vertices[0] = vertices.at(i);
triangle.vertices[1] = vertices.at(i + 1);
triangle.vertices[2] = vertices.at(i + 2);
m_triangle_list.append(triangle);
// Triangle 2
triangle.vertices[0] = vertices.at(i + 2);
triangle.vertices[1] = vertices.at(i + 3);
triangle.vertices[2] = vertices.at(i);
m_triangle_list.append(triangle);
}
} else if (primitive_type == GPU::PrimitiveType::TriangleFan) {
Triangle triangle;
triangle.vertices[0] = vertices.at(0); // Root vertex is always the vertex defined first
// This is technically `n-2` triangles. We start at index 1
for (size_t i = 1; i < vertices.size() - 1; i++) {
triangle.vertices[1] = vertices.at(i);
triangle.vertices[2] = vertices.at(i + 1);
m_triangle_list.append(triangle);
}
} else if (primitive_type == GPU::PrimitiveType::TriangleStrip) {
Triangle triangle;
if (vertices.size() < 3)
return;
for (size_t i = 0; i < vertices.size() - 2; i++) {
if (i % 2 == 0) {
triangle.vertices[0] = vertices.at(i);
triangle.vertices[1] = vertices.at(i + 1);
triangle.vertices[2] = vertices.at(i + 2);
} else {
triangle.vertices[0] = vertices.at(i + 1);
triangle.vertices[1] = vertices.at(i);
triangle.vertices[2] = vertices.at(i + 2);
}
m_triangle_list.append(triangle);
}
}
// Clip triangles
for (auto& triangle : m_triangle_list) {
m_clipped_vertices.clear_with_capacity();
m_clipped_vertices.unchecked_append(triangle.vertices[0]);
m_clipped_vertices.unchecked_append(triangle.vertices[1]);
m_clipped_vertices.unchecked_append(triangle.vertices[2]);
m_clipper.clip_triangle_against_frustum(m_clipped_vertices);
if (m_clip_planes.size() > 0)
m_clipper.clip_triangle_against_user_defined(m_clipped_vertices, m_clip_planes);
if (m_clipped_vertices.size() < 3)
continue;
for (auto& vertex : m_clipped_vertices)
calculate_vertex_window_coordinates(vertex);
Triangle tri;
tri.vertices[0] = m_clipped_vertices[0];
for (size_t i = 1; i < m_clipped_vertices.size() - 1; i++) {
tri.vertices[1] = m_clipped_vertices[i];
tri.vertices[2] = m_clipped_vertices[i + 1];
m_processed_triangles.append(tri);
}
}
for (auto& triangle : m_processed_triangles)
rasterize_triangle(triangle);
}
ALWAYS_INLINE void Device::shade_fragments(PixelQuad& quad)
{
if (m_current_fragment_shader) {
m_shader_processor.execute(quad, *m_current_fragment_shader);
return;
}
Array<Vector4<f32x4>, GPU::NUM_TEXTURE_UNITS> texture_stage_texel;
auto current_color = quad.get_input_vector4(SHADER_INPUT_VERTEX_COLOR);
for (GPU::TextureUnitIndex i = 0; i < GPU::NUM_TEXTURE_UNITS; ++i) {
if (!m_texture_unit_configuration[i].enabled)
continue;
auto const& sampler = m_samplers[i];
// OpenGL 2.0 ¶ 3.5.1 states (in a roundabout way) that texture coordinates must be divided by Q
auto homogeneous_texture_coordinate = quad.get_input_vector4(SHADER_INPUT_FIRST_TEXCOORD + i * 4);
auto texel = sampler.sample_2d(homogeneous_texture_coordinate.xy() / homogeneous_texture_coordinate.w());
INCREASE_STATISTICS_COUNTER(g_num_sampler_calls, 1);
if (m_samplers_need_texture_staging)
texture_stage_texel[i] = texel;
// FIXME: implement support for GL_ALPHA, GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_INTENSITY and GL_RGB internal formats
auto& fixed_function_env = sampler.config().fixed_function_texture_environment;
switch (fixed_function_env.env_mode) {
case GPU::TextureEnvMode::Add:
current_color.set_x(current_color.x() + texel.x());
current_color.set_y(current_color.y() + texel.y());
current_color.set_z(current_color.z() + texel.z());
current_color.set_w(current_color.w() * texel.w());
break;
case GPU::TextureEnvMode::Blend: {
auto blend_color = expand4(fixed_function_env.color);
current_color.set_x(mix(current_color.x(), blend_color.x(), texel.x()));
current_color.set_y(mix(current_color.y(), blend_color.y(), texel.y()));
current_color.set_z(mix(current_color.z(), blend_color.z(), texel.z()));
current_color.set_w(current_color.w() * texel.w());
break;
}
case GPU::TextureEnvMode::Combine: {
auto get_source_color = [&](GPU::TextureSource source, u8 texture_stage) {
switch (source) {
case GPU::TextureSource::Constant:
return expand4(fixed_function_env.color);
case GPU::TextureSource::Previous:
return current_color;
case GPU::TextureSource::PrimaryColor:
return quad.get_input_vector4(SHADER_INPUT_VERTEX_COLOR);
case GPU::TextureSource::Texture:
return texel;
case GPU::TextureSource::TextureStage:
return texture_stage_texel[texture_stage];
}
VERIFY_NOT_REACHED();
};
auto get_argument_value = [](GPU::TextureOperand operand, auto value) {
switch (operand) {
case GPU::TextureOperand::OneMinusSourceAlpha:
case GPU::TextureOperand::OneMinusSourceColor:
return expand4(FloatVector4 { 1.f, 1.f, 1.f, 1.f }) - value;
case GPU::TextureOperand::SourceAlpha:
case GPU::TextureOperand::SourceColor:
return value;
}
VERIFY_NOT_REACHED();
};
auto calculate_combinator = [](GPU::TextureCombinator combinator, auto arg0, auto arg1, auto arg2) {
switch (combinator) {
case GPU::TextureCombinator::Add:
return arg0 + arg1;
case GPU::TextureCombinator::AddSigned:
return arg0 + arg1 - expand4(FloatVector4 { .5f, .5f, .5f, .5f });
case GPU::TextureCombinator::Dot3RGB:
case GPU::TextureCombinator::Dot3RGBA: {
auto scalar = 4.f * ((arg0.x() - .5f) * (arg1.x() - .5f) + (arg0.y() - 0.5f) * (arg1.y() - 0.5f) + (arg0.z() - 0.5f) * (arg1.z() - 0.5f));
return Vector4<f32x4> { scalar, scalar, scalar, scalar };
}
case GPU::TextureCombinator::Interpolate:
return mix(arg0, arg1, arg2);
case GPU::TextureCombinator::Modulate:
return arg0 * arg1;
case GPU::TextureCombinator::Replace:
return arg0;
case GPU::TextureCombinator::Subtract:
return arg0 - arg1;
}
VERIFY_NOT_REACHED();
};
auto calculate_color = [&](GPU::TextureCombinator combinator, auto& operands, auto& sources, u8 texture_stage) {
auto arg0 = get_argument_value(operands[0], get_source_color(sources[0], texture_stage));
auto arg1 = get_argument_value(operands[1], get_source_color(sources[1], texture_stage));
auto arg2 = get_argument_value(operands[2], get_source_color(sources[2], texture_stage));
return calculate_combinator(combinator, arg0, arg1, arg2);
};
auto rgb_color = calculate_color(
fixed_function_env.rgb_combinator,
fixed_function_env.rgb_operand,
fixed_function_env.rgb_source,
fixed_function_env.rgb_source_texture_stage);
auto alpha_color = calculate_color(
fixed_function_env.alpha_combinator,
fixed_function_env.alpha_operand,
fixed_function_env.alpha_source,
fixed_function_env.alpha_source_texture_stage);
current_color.set_x(rgb_color.x() * fixed_function_env.rgb_scale);
current_color.set_y(rgb_color.y() * fixed_function_env.rgb_scale);
current_color.set_z(rgb_color.z() * fixed_function_env.rgb_scale);
current_color.set_w(alpha_color.w() * fixed_function_env.alpha_scale);
current_color.clamp(expand4(0.f), expand4(1.f));
break;
}
case GPU::TextureEnvMode::Decal: {
auto dst_alpha = texel.w();
current_color.set_x(mix(current_color.x(), texel.x(), dst_alpha));
current_color.set_y(mix(current_color.y(), texel.y(), dst_alpha));
current_color.set_z(mix(current_color.z(), texel.z(), dst_alpha));
break;
}
case GPU::TextureEnvMode::Modulate:
current_color = current_color * texel;
break;
case GPU::TextureEnvMode::Replace:
current_color = texel;
break;
}
}
// Calculate fog
// Math from here: https://opengl-notes.readthedocs.io/en/latest/topics/texturing/aliasing.html
if (m_options.fog_enabled) {
f32x4 factor;
switch (m_options.fog_mode) {
case GPU::FogMode::Linear:
factor = (m_options.fog_end - quad.fog_depth) * m_one_over_fog_depth;
break;
case GPU::FogMode::Exp: {
auto argument = -m_options.fog_density * quad.fog_depth;
factor = exp_approximate(argument);
} break;
case GPU::FogMode::Exp2: {
auto argument = m_options.fog_density * quad.fog_depth;
argument *= -argument;
factor = exp_approximate(argument);
} break;
default:
VERIFY_NOT_REACHED();
}
// Mix texel's RGB with fog's RBG - leave alpha alone
auto fog_color = expand4(m_options.fog_color);
current_color.set_x(mix(fog_color.x(), current_color.x(), factor));
current_color.set_y(mix(fog_color.y(), current_color.y(), factor));
current_color.set_z(mix(fog_color.z(), current_color.z(), factor));
}
quad.set_output(SHADER_OUTPUT_FIRST_COLOR, current_color.x());
quad.set_output(SHADER_OUTPUT_FIRST_COLOR + 1, current_color.y());
quad.set_output(SHADER_OUTPUT_FIRST_COLOR + 2, current_color.z());
// Multiply coverage with the fragment's alpha to obtain the final alpha value
quad.set_output(SHADER_OUTPUT_FIRST_COLOR + 3, current_color.w() * quad.coverage);
}
void Device::resize(Gfx::IntSize size)
{
auto frame_buffer_or_error = FrameBuffer<GPU::ColorType, GPU::DepthType, GPU::StencilType>::try_create(size);
m_frame_buffer = MUST(frame_buffer_or_error);
}
void Device::clear_color(FloatVector4 const& color)
{
auto const fill_color = to_argb32(color);
auto clear_rect = m_frame_buffer->rect();
if (m_options.scissor_enabled)
clear_rect.intersect(m_options.scissor_box);
m_frame_buffer->color_buffer()->fill(fill_color, clear_rect);
}
void Device::clear_depth(GPU::DepthType depth)
{
auto clear_rect = m_frame_buffer->rect();
if (m_options.scissor_enabled)
clear_rect.intersect(m_options.scissor_box);
m_frame_buffer->depth_buffer()->fill(depth, clear_rect);
}
void Device::clear_stencil(GPU::StencilType value)
{
auto clear_rect = m_frame_buffer->rect();
if (m_options.scissor_enabled)
clear_rect.intersect(m_options.scissor_box);
m_frame_buffer->stencil_buffer()->fill(value, clear_rect);
}
GPU::ImageDataLayout Device::color_buffer_data_layout(Vector2<u32> size, Vector2<i32> offset)
{
return {
.pixel_type = {
.format = GPU::PixelFormat::BGRA,
.bits = GPU::PixelComponentBits::B8_8_8_8,
.data_type = GPU::PixelDataType::UnsignedInt,
.components_order = GPU::ComponentsOrder::Reversed,
},
.dimensions = {
.width = static_cast<u32>(m_frame_buffer->rect().width()),
.height = static_cast<u32>(m_frame_buffer->rect().height()),
.depth = 1,
},
.selection = {
.offset_x = offset.x(),
.offset_y = offset.y(),
.offset_z = 0,
.width = size.x(),
.height = size.y(),
.depth = 1,
},
};
}
GPU::ImageDataLayout Device::depth_buffer_data_layout(Vector2<u32> size, Vector2<i32> offset)
{
return {
.pixel_type = {
.format = GPU::PixelFormat::DepthComponent,
.bits = GPU::PixelComponentBits::AllBits,
.data_type = GPU::PixelDataType::Float,
},
.dimensions = {
.width = static_cast<u32>(m_frame_buffer->rect().width()),
.height = static_cast<u32>(m_frame_buffer->rect().height()),
.depth = 1,
},
.selection = {
.offset_x = offset.x(),
.offset_y = offset.y(),
.offset_z = 0,
.width = size.x(),
.height = size.y(),
.depth = 1,
},
};
}
void Device::blit_from_color_buffer(Gfx::Bitmap& target)
{
m_frame_buffer->color_buffer()->blit_flipped_to_bitmap(target, m_frame_buffer->rect());
if constexpr (ENABLE_STATISTICS_OVERLAY)
draw_statistics_overlay(target);
}
void Device::blit_from_color_buffer(NonnullRefPtr<GPU::Image> image, u32 level, Vector2<u32> input_size, Vector2<i32> input_offset, Vector3<i32> output_offset)
{
auto input_layout = color_buffer_data_layout(input_size, input_offset);
auto const* input_data = m_frame_buffer->color_buffer()->scanline(0);
auto const& softgpu_image = reinterpret_cast<Image*>(image.ptr());
auto output_layout = softgpu_image->image_data_layout(level, output_offset);
auto* output_data = softgpu_image->texel_pointer(level, 0, 0, 0);
PixelConverter converter { input_layout, output_layout };
auto conversion_result = converter.convert(input_data, output_data, {});
if (conversion_result.is_error())
dbgln("Pixel conversion failed: {}", conversion_result.error().string_literal());
}
void Device::blit_from_color_buffer(void* output_data, Vector2<i32> input_offset, GPU::ImageDataLayout const& output_layout)
{
auto const& output_selection = output_layout.selection;
auto input_layout = color_buffer_data_layout({ output_selection.width, output_selection.height }, input_offset);
PixelConverter converter { input_layout, output_layout };
auto const* input_data = m_frame_buffer->color_buffer()->scanline(0);
auto conversion_result = converter.convert(input_data, output_data, {});
if (conversion_result.is_error())
dbgln("Pixel conversion failed: {}", conversion_result.error().string_literal());
}
void Device::blit_from_depth_buffer(void* output_data, Vector2<i32> input_offset, GPU::ImageDataLayout const& output_layout)
{
auto const& output_selection = output_layout.selection;
auto input_layout = depth_buffer_data_layout({ output_selection.width, output_selection.height }, input_offset);
PixelConverter converter { input_layout, output_layout };
auto const* input_data = m_frame_buffer->depth_buffer()->scanline(0);
auto conversion_result = converter.convert(input_data, output_data, {});
if (conversion_result.is_error())
dbgln("Pixel conversion failed: {}", conversion_result.error().string_literal());
}
void Device::blit_from_depth_buffer(NonnullRefPtr<GPU::Image> image, u32 level, Vector2<u32> input_size, Vector2<i32> input_offset, Vector3<i32> output_offset)
{
auto input_layout = depth_buffer_data_layout(input_size, input_offset);
auto const* input_data = m_frame_buffer->depth_buffer()->scanline(0);
auto const& softgpu_image = reinterpret_cast<Image*>(image.ptr());
auto output_layout = softgpu_image->image_data_layout(level, output_offset);
auto* output_data = softgpu_image->texel_pointer(level, 0, 0, 0);
PixelConverter converter { input_layout, output_layout };
auto conversion_result = converter.convert(input_data, output_data, {});
if (conversion_result.is_error())
dbgln("Pixel conversion failed: {}", conversion_result.error().string_literal());
}
void Device::blit_to_color_buffer_at_raster_position(void const* input_data, GPU::ImageDataLayout const& input_layout)
{
if (!m_raster_position.valid)
return;
auto input_selection = input_layout.selection;
INCREASE_STATISTICS_COUNTER(g_num_pixels, input_selection.width * input_selection.height);
INCREASE_STATISTICS_COUNTER(g_num_pixels_shaded, input_selection.width * input_selection.height);
auto const rasterization_rect = get_rasterization_rect_of_size({ input_selection.width, input_selection.height });
auto output_layout = color_buffer_data_layout(
{ static_cast<u32>(rasterization_rect.width()), static_cast<u32>(rasterization_rect.height()) },
{ rasterization_rect.x(), rasterization_rect.y() });
PixelConverter converter { input_layout, output_layout };
auto* output_data = m_frame_buffer->color_buffer()->scanline(0);
auto conversion_result = converter.convert(input_data, output_data, {});
if (conversion_result.is_error())
dbgln("Pixel conversion failed: {}", conversion_result.error().string_literal());
}
void Device::blit_to_depth_buffer_at_raster_position(void const* input_data, GPU::ImageDataLayout const& input_layout)
{
if (!m_raster_position.valid)
return;
auto input_selection = input_layout.selection;
auto const rasterization_rect = get_rasterization_rect_of_size({ input_selection.width, input_selection.height });
auto output_layout = depth_buffer_data_layout(
{ static_cast<u32>(rasterization_rect.width()), static_cast<u32>(rasterization_rect.height()) },
{ rasterization_rect.x(), rasterization_rect.y() });
PixelConverter converter { input_layout, output_layout };
auto* output_data = m_frame_buffer->depth_buffer()->scanline(0);
auto conversion_result = converter.convert(input_data, output_data, {});
if (conversion_result.is_error())
dbgln("Pixel conversion failed: {}", conversion_result.error().string_literal());
}
void Device::draw_statistics_overlay(Gfx::Bitmap& target)
{
static Core::ElapsedTimer timer;
static String debug_string;
static int frame_counter;
frame_counter++;
i64 milliseconds = 0;
if (timer.is_valid())
milliseconds = timer.elapsed();
else
timer.start();
Gfx::Painter painter { target };
if (milliseconds > MILLISECONDS_PER_STATISTICS_PERIOD) {
int num_rendertarget_pixels = m_frame_buffer->rect().size().area();
StringBuilder builder;
builder.appendff("Timings : {:.1}ms {:.1}FPS\n",
static_cast<double>(milliseconds) / frame_counter,
(milliseconds > 0) ? 1000.0 * frame_counter / milliseconds : 9999.0);
builder.appendff("Triangles : {}\n", g_num_rasterized_triangles);
builder.appendff("SIMD usage : {}%\n", g_num_quads > 0 ? g_num_pixels_shaded * 25 / g_num_quads : 0);
builder.appendff("Pixels : {}, Stencil: {}%, Shaded: {}%, Blended: {}%, Overdraw: {}%\n",
g_num_pixels,
g_num_pixels > 0 ? g_num_stencil_writes * 100 / g_num_pixels : 0,
g_num_pixels > 0 ? g_num_pixels_shaded * 100 / g_num_pixels : 0,
g_num_pixels_shaded > 0 ? g_num_pixels_blended * 100 / g_num_pixels_shaded : 0,
num_rendertarget_pixels > 0 ? g_num_pixels_shaded * 100 / num_rendertarget_pixels - 100 : 0);
builder.appendff("Sampler calls: {}\n", g_num_sampler_calls);
debug_string = builder.to_string().release_value_but_fixme_should_propagate_errors();
frame_counter = 0;
timer.start();
}
g_num_rasterized_triangles = 0;
g_num_pixels = 0;
g_num_pixels_shaded = 0;
g_num_pixels_blended = 0;
g_num_sampler_calls = 0;
g_num_stencil_writes = 0;
g_num_quads = 0;
auto& font = Gfx::FontDatabase::default_fixed_width_font();
for (int y = -1; y < 2; y++)
for (int x = -1; x < 2; x++)
if (x != 0 && y != 0)
painter.draw_text(target.rect().translated(x + 2, y + 2), debug_string, font, Gfx::TextAlignment::TopLeft, Gfx::Color::Black);
painter.draw_text(target.rect().translated(2, 2), debug_string, font, Gfx::TextAlignment::TopLeft, Gfx::Color::White);
}
void Device::set_options(GPU::RasterizerOptions const& options)
{
m_options = options;
if (m_options.fog_enabled)
m_one_over_fog_depth = 1.f / (m_options.fog_end - m_options.fog_start);
}
void Device::set_light_model_params(GPU::LightModelParameters const& lighting_model)
{
m_lighting_model = lighting_model;
}
NonnullRefPtr<GPU::Image> Device::create_image(GPU::PixelFormat const& pixel_format, u32 width, u32 height, u32 depth, u32 max_levels)
{
VERIFY(width > 0);
VERIFY(height > 0);
VERIFY(depth > 0);
VERIFY(max_levels > 0);
return adopt_ref(*new Image(this, pixel_format, width, height, depth, max_levels));
}
ErrorOr<NonnullRefPtr<GPU::Shader>> Device::create_shader(GPU::IR::Shader const& intermediate_representation)
{
ShaderCompiler compiler;
auto shader = TRY(compiler.compile(this, intermediate_representation));
return shader;
}
void Device::set_model_view_transform(Gfx::FloatMatrix4x4 const& model_view_transform)
{
m_model_view_transform = model_view_transform;
// Set up normals transform by taking the upper left 3x3 elements from the model view matrix
// See section 2.11.3 of the OpenGL 1.5 spec
m_normal_transform = model_view_transform.submatrix_from_topleft<3>().transpose().inverse();
}
void Device::set_projection_transform(Gfx::FloatMatrix4x4 const& projection_transform)
{
m_projection_transform = projection_transform;
}
void Device::set_sampler_config(unsigned sampler, GPU::SamplerConfig const& config)
{
VERIFY(config.bound_image.is_null() || config.bound_image->ownership_token() == this);
m_samplers[sampler].set_config(config);
m_samplers_need_texture_staging = any_of(m_samplers, [](auto const& sampler) {
auto const& fixed_function_env = sampler.config().fixed_function_texture_environment;
if (fixed_function_env.env_mode != GPU::TextureEnvMode::Combine)
return false;
return any_of(fixed_function_env.alpha_source, [](auto texture_source) { return texture_source == GPU::TextureSource::TextureStage; })
|| any_of(fixed_function_env.rgb_source, [](auto texture_source) { return texture_source == GPU::TextureSource::TextureStage; });
});
}
void Device::set_light_state(unsigned int light_id, GPU::Light const& light)
{
m_lights.at(light_id) = light;
}
void Device::set_material_state(GPU::Face face, GPU::Material const& material)
{
m_materials[face] = material;
}
void Device::set_stencil_configuration(GPU::Face face, GPU::StencilConfiguration const& stencil_configuration)
{
m_stencil_configuration[face] = stencil_configuration;
}
void Device::set_texture_unit_configuration(GPU::TextureUnitIndex index, GPU::TextureUnitConfiguration const& configuration)
{
m_texture_unit_configuration[index] = configuration;
}
void Device::set_raster_position(GPU::RasterPosition const& raster_position)
{
m_raster_position = raster_position;
}
void Device::set_clip_planes(Vector<FloatVector4> const& clip_planes)
{
m_clip_planes = clip_planes;
}
void Device::set_raster_position(FloatVector4 const& position)
{
auto const eye_coordinates = m_model_view_transform * position;
auto const clip_coordinates = m_projection_transform * eye_coordinates;
// FIXME: implement clipping
m_raster_position.valid = true;
auto ndc_coordinates = clip_coordinates / clip_coordinates.w();
ndc_coordinates.set_w(clip_coordinates.w());
auto const viewport = m_options.viewport;
auto const viewport_half_width = viewport.width() / 2.0f;
auto const viewport_half_height = viewport.height() / 2.0f;
auto const viewport_center_x = viewport.x() + viewport_half_width;
auto const viewport_center_y = viewport.y() + viewport_half_height;
auto const depth_half_range = (m_options.depth_max - m_options.depth_min) / 2;
auto const depth_halfway = (m_options.depth_min + m_options.depth_max) / 2;
// FIXME: implement other raster position properties such as color and texcoords
m_raster_position.window_coordinates = {
viewport_center_x + ndc_coordinates.x() * viewport_half_width,
viewport_center_y + ndc_coordinates.y() * viewport_half_height,
depth_halfway + ndc_coordinates.z() * depth_half_range,
ndc_coordinates.w(),
};
m_raster_position.eye_coordinate_distance = eye_coordinates.length();
}
void Device::bind_fragment_shader(RefPtr<GPU::Shader> shader)
{
VERIFY(shader.is_null() || shader->ownership_token() == this);
if (shader.is_null()) {
m_current_fragment_shader = nullptr;
return;
}
auto softgpu_shader = static_ptr_cast<Shader>(shader);
m_current_fragment_shader = softgpu_shader;
}
Gfx::IntRect Device::get_rasterization_rect_of_size(Gfx::IntSize size) const
{
// Round the X and Y floating point coordinates to the nearest integer; OpenGL 1.5 spec:
// "Any fragments whose centers lie inside of this rectangle (or on its bottom or left
// boundaries) are produced in correspondence with this particular group of elements."
return {
round_to<int>(m_raster_position.window_coordinates.x()),
round_to<int>(m_raster_position.window_coordinates.y()),
size.width(),
size.height(),
};
}
}
extern "C" {
GPU::Device* serenity_gpu_create_device(Gfx::IntSize size)
{
return make<SoftGPU::Device>(size).leak_ptr();
}
}
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