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ladybird/Userland/Libraries/LibGL/SoftwareGLContext.cpp
Stephan Unverwerth 220ac5eb02 LibGL: Fix clipping and interpolate vertex attributes 
The previous clipping implementation was problematic especially when
clipping against the near plane. Triangles are now correctly clipped
using homogenous coordinates against all frustum planes.

Texture coordinates and vertex colors are now correctly interpolated.
The earier implementation was just a placeholder.
2021-08-18 20:30:58 +02:00

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/*
* Copyright (c) 2021, Jesse Buhagiar <jooster669@gmail.com>
* Copyright (c) 2021, Stephan Unverwerth <s.unverwerth@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "SoftwareGLContext.h"
#include "GLStruct.h"
#include "SoftwareRasterizer.h"
#include <AK/Assertions.h>
#include <AK/Debug.h>
#include <AK/Format.h>
#include <AK/QuickSort.h>
#include <AK/TemporaryChange.h>
#include <AK/Variant.h>
#include <AK/Vector.h>
#include <LibGfx/Bitmap.h>
#include <LibGfx/Painter.h>
#include <LibGfx/Vector4.h>
using AK::dbgln;
namespace GL {
// FIXME: We should set this up when we create the context!
static constexpr size_t MATRIX_STACK_LIMIT = 1024;
#define APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(name, ...) \
if (should_append_to_listing()) { \
append_to_listing<&SoftwareGLContext::name>(__VA_ARGS__); \
if (!should_execute_after_appending_to_listing()) \
return; \
}
#define RETURN_WITH_ERROR_IF(condition, error) \
if (condition) { \
if (m_error == GL_NO_ERROR) \
m_error = error; \
return; \
}
#define RETURN_VALUE_WITH_ERROR_IF(condition, error, return_value) \
if (condition) { \
if (m_error == GL_NO_ERROR) \
m_error = error; \
return return_value; \
}
SoftwareGLContext::SoftwareGLContext(Gfx::Bitmap& frontbuffer)
: m_frontbuffer(frontbuffer)
, m_rasterizer(frontbuffer.size())
{
}
void SoftwareGLContext::gl_begin(GLenum mode)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_begin, mode);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(mode < GL_TRIANGLES || mode > GL_POLYGON, GL_INVALID_ENUM);
m_current_draw_mode = mode;
m_in_draw_state = true; // Certain commands will now generate an error
}
void SoftwareGLContext::gl_clear(GLbitfield mask)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_clear, mask);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(mask & ~(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT), GL_INVALID_ENUM);
if (mask & GL_COLOR_BUFFER_BIT)
m_rasterizer.clear_color(m_clear_color);
if (mask & GL_DEPTH_BUFFER_BIT)
m_rasterizer.clear_depth(static_cast<float>(m_clear_depth));
}
void SoftwareGLContext::gl_clear_color(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_clear_color, red, green, blue, alpha);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
m_clear_color = { red, green, blue, alpha };
}
void SoftwareGLContext::gl_clear_depth(GLdouble depth)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_clear_depth, depth);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
m_clear_depth = depth;
}
void SoftwareGLContext::gl_color(GLdouble r, GLdouble g, GLdouble b, GLdouble a)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_color, r, g, b, a);
m_current_vertex_color = { (float)r, (float)g, (float)b, (float)a };
}
void SoftwareGLContext::gl_end()
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_end);
// 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 mulitplying 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 vertices are sorted (for the rasteriser, how are we doing this? 3Dfx did this top to bottom in terms of vertex y coordinates)
// 6. The vertices are then sent off to the rasteriser and drawn to the screen
float scr_width = m_frontbuffer->width();
float scr_height = m_frontbuffer->height();
// Make sure we had a `glBegin` before this call...
RETURN_WITH_ERROR_IF(!m_in_draw_state, GL_INVALID_OPERATION);
triangle_list.clear_with_capacity();
processed_triangles.clear_with_capacity();
// Let's construct some triangles
if (m_current_draw_mode == GL_TRIANGLES) {
GLTriangle triangle;
for (size_t i = 0; i < vertex_list.size(); i += 3) {
triangle.vertices[0] = vertex_list.at(i);
triangle.vertices[1] = vertex_list.at(i + 1);
triangle.vertices[2] = vertex_list.at(i + 2);
triangle_list.append(triangle);
}
} else if (m_current_draw_mode == GL_QUADS) {
// We need to construct two triangles to form the quad
GLTriangle triangle;
VERIFY(vertex_list.size() % 4 == 0);
for (size_t i = 0; i < vertex_list.size(); i += 4) {
// Triangle 1
triangle.vertices[0] = vertex_list.at(i);
triangle.vertices[1] = vertex_list.at(i + 1);
triangle.vertices[2] = vertex_list.at(i + 2);
triangle_list.append(triangle);
// Triangle 2
triangle.vertices[0] = vertex_list.at(i + 2);
triangle.vertices[1] = vertex_list.at(i + 3);
triangle.vertices[2] = vertex_list.at(i);
triangle_list.append(triangle);
}
} else if (m_current_draw_mode == GL_TRIANGLE_FAN) {
GLTriangle triangle;
triangle.vertices[0] = vertex_list.at(0); // Root vertex is always the vertex defined first
for (size_t i = 1; i < vertex_list.size() - 1; i++) // This is technically `n-2` triangles. We start at index 1
{
triangle.vertices[1] = vertex_list.at(i);
triangle.vertices[2] = vertex_list.at(i + 1);
triangle_list.append(triangle);
}
} else if (m_current_draw_mode == GL_TRIANGLE_STRIP) {
GLTriangle triangle;
for (size_t i = 0; i < vertex_list.size() - 2; i++) {
triangle.vertices[0] = vertex_list.at(i);
triangle.vertices[1] = vertex_list.at(i + 1);
triangle.vertices[2] = vertex_list.at(i + 2);
triangle_list.append(triangle);
}
} else {
vertex_list.clear_with_capacity();
RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
}
vertex_list.clear_with_capacity();
auto mvp = m_projection_matrix * m_model_view_matrix;
// Now let's transform each triangle and send that to the GPU
for (size_t i = 0; i < triangle_list.size(); i++) {
GLTriangle& triangle = triangle_list.at(i);
// First multiply the vertex by the MODELVIEW matrix and then the PROJECTION matrix
triangle.vertices[0].position = mvp * triangle.vertices[0].position;
triangle.vertices[1].position = mvp * triangle.vertices[1].position;
triangle.vertices[2].position = mvp * triangle.vertices[2].position;
// At this point, we're in clip space
// Here's where we do the clipping. This is a really crude implementation of the
// https://learnopengl.com/Getting-started/Coordinate-Systems
// "Note that if only a part of a primitive e.g. a triangle is outside the clipping volume OpenGL
// will reconstruct the triangle as one or more triangles to fit inside the clipping range. "
//
// ALL VERTICES ARE DEFINED IN A CLOCKWISE ORDER
// Okay, let's do some face culling first
m_clipped_vertices.clear_with_capacity();
m_clipped_vertices.append(triangle.vertices[0]);
m_clipped_vertices.append(triangle.vertices[1]);
m_clipped_vertices.append(triangle.vertices[2]);
m_clipper.clip_triangle_against_frustum(m_clipped_vertices);
if (m_clipped_vertices.size() < 3)
continue;
for (auto& vec : m_clipped_vertices) {
// perspective divide
float w = vec.position.w();
vec.position.set_x(vec.position.x() / w);
vec.position.set_y(vec.position.y() / w);
vec.position.set_z(vec.position.z() / w);
vec.position.set_w(1 / w);
// to screen space
vec.position.set_x(scr_width / 2 + vec.position.x() * scr_width / 2);
vec.position.set_y(scr_height / 2 - vec.position.y() * scr_height / 2);
}
GLTriangle 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];
processed_triangles.append(tri);
}
}
for (size_t i = 0; i < processed_triangles.size(); i++) {
GLTriangle& triangle = processed_triangles.at(i);
// Let's calculate the (signed) area of the triangle
// https://cp-algorithms.com/geometry/oriented-triangle-area.html
float dxAB = triangle.vertices[0].position.x() - triangle.vertices[1].position.x(); // A.x - B.x
float dxBC = triangle.vertices[1].position.x() - triangle.vertices[2].position.x(); // B.X - C.x
float dyAB = triangle.vertices[0].position.y() - triangle.vertices[1].position.y();
float dyBC = triangle.vertices[1].position.y() - triangle.vertices[2].position.y();
float area = (dxAB * dyBC) - (dxBC * dyAB);
if (area == 0.0f)
continue;
if (m_cull_faces) {
bool is_front = (m_front_face == GL_CCW ? area > 0 : area < 0);
if (is_front && (m_culled_sides == GL_FRONT || m_culled_sides == GL_FRONT_AND_BACK))
continue;
if (!is_front && (m_culled_sides == GL_BACK || m_culled_sides == GL_FRONT_AND_BACK))
continue;
}
m_rasterizer.submit_triangle(triangle, m_texture_units);
}
m_in_draw_state = false;
}
void SoftwareGLContext::gl_frustum(GLdouble left, GLdouble right, GLdouble bottom, GLdouble top, GLdouble near_val, GLdouble far_val)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_frustum, left, right, bottom, top, near_val, far_val);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
// Let's do some math!
// FIXME: Are we losing too much precision by doing this?
float a = static_cast<float>((right + left) / (right - left));
float b = static_cast<float>((top + bottom) / (top - bottom));
float c = static_cast<float>(-((far_val + near_val) / (far_val - near_val)));
float d = static_cast<float>(-((2 * (far_val * near_val)) / (far_val - near_val)));
FloatMatrix4x4 frustum {
((2 * (float)near_val) / ((float)right - (float)left)), 0, a, 0,
0, ((2 * (float)near_val) / ((float)top - (float)bottom)), b, 0,
0, 0, c, d,
0, 0, -1, 0
};
if (m_current_matrix_mode == GL_PROJECTION) {
m_projection_matrix = m_projection_matrix * frustum;
} else if (m_current_matrix_mode == GL_MODELVIEW) {
dbgln_if(GL_DEBUG, "glFrustum(): frustum created with curr_matrix_mode == GL_MODELVIEW!!!");
m_projection_matrix = m_model_view_matrix * frustum;
}
}
void SoftwareGLContext::gl_ortho(GLdouble left, GLdouble right, GLdouble bottom, GLdouble top, GLdouble near_val, GLdouble far_val)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_ortho, left, right, bottom, top, near_val, far_val);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(left == right || bottom == top || near_val == far_val, GL_INVALID_VALUE);
auto rl = right - left;
auto tb = top - bottom;
auto fn = far_val - near_val;
auto tx = -(right + left) / rl;
auto ty = -(top + bottom) / tb;
auto tz = -(far_val + near_val) / fn;
FloatMatrix4x4 projection {
static_cast<float>(2 / rl), 0, 0, static_cast<float>(tx),
0, static_cast<float>(2 / tb), 0, static_cast<float>(ty),
0, 0, static_cast<float>(-2 / fn), static_cast<float>(tz),
0, 0, 0, 1
};
if (m_current_matrix_mode == GL_PROJECTION) {
m_projection_matrix = m_projection_matrix * projection;
} else if (m_current_matrix_mode == GL_MODELVIEW) {
m_projection_matrix = m_model_view_matrix * projection;
}
}
GLenum SoftwareGLContext::gl_get_error()
{
if (m_in_draw_state)
return GL_INVALID_OPERATION;
auto last_error = m_error;
m_error = GL_NO_ERROR;
return last_error;
}
GLubyte* SoftwareGLContext::gl_get_string(GLenum name)
{
RETURN_VALUE_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION, nullptr);
switch (name) {
case GL_VENDOR:
return reinterpret_cast<GLubyte*>(const_cast<char*>("The SerenityOS Developers"));
case GL_RENDERER:
return reinterpret_cast<GLubyte*>(const_cast<char*>("SerenityOS OpenGL"));
case GL_VERSION:
return reinterpret_cast<GLubyte*>(const_cast<char*>("1.5"));
case GL_EXTENSIONS:
return reinterpret_cast<GLubyte*>(const_cast<char*>(""));
default:
dbgln_if(GL_DEBUG, "glGetString(): Unknown enum name!");
break;
}
RETURN_VALUE_WITH_ERROR_IF(true, GL_INVALID_ENUM, nullptr);
}
void SoftwareGLContext::gl_load_identity()
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_load_identity);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
if (m_current_matrix_mode == GL_PROJECTION)
m_projection_matrix = FloatMatrix4x4::identity();
else if (m_current_matrix_mode == GL_MODELVIEW)
m_model_view_matrix = FloatMatrix4x4::identity();
else
VERIFY_NOT_REACHED();
}
void SoftwareGLContext::gl_load_matrix(const FloatMatrix4x4& matrix)
{
if (should_append_to_listing()) {
auto ptr = store_in_listing(matrix);
append_to_listing<&SoftwareGLContext::gl_load_matrix>(*ptr);
if (!should_execute_after_appending_to_listing())
return;
}
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
if (m_current_matrix_mode == GL_PROJECTION)
m_projection_matrix = matrix;
else if (m_current_matrix_mode == GL_MODELVIEW)
m_model_view_matrix = matrix;
else
VERIFY_NOT_REACHED();
}
void SoftwareGLContext::gl_matrix_mode(GLenum mode)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_matrix_mode, mode);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(mode < GL_MODELVIEW || mode > GL_PROJECTION, GL_INVALID_ENUM);
m_current_matrix_mode = mode;
}
void SoftwareGLContext::gl_push_matrix()
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_push_matrix);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
dbgln_if(GL_DEBUG, "glPushMatrix(): Pushing matrix to the matrix stack (matrix_mode {})", m_current_matrix_mode);
switch (m_current_matrix_mode) {
case GL_PROJECTION:
RETURN_WITH_ERROR_IF(m_projection_matrix_stack.size() >= MATRIX_STACK_LIMIT, GL_STACK_OVERFLOW);
m_projection_matrix_stack.append(m_projection_matrix);
break;
case GL_MODELVIEW:
RETURN_WITH_ERROR_IF(m_model_view_matrix_stack.size() >= MATRIX_STACK_LIMIT, GL_STACK_OVERFLOW);
m_model_view_matrix_stack.append(m_model_view_matrix);
break;
default:
dbgln_if(GL_DEBUG, "glPushMatrix(): Attempt to push matrix with invalid matrix mode {})", m_current_matrix_mode);
return;
}
}
void SoftwareGLContext::gl_pop_matrix()
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_pop_matrix);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
dbgln_if(GL_DEBUG, "glPopMatrix(): Popping matrix from matrix stack (matrix_mode = {})", m_current_matrix_mode);
// FIXME: Make sure stack::top() doesn't cause any nasty issues if it's empty (that could result in a lockup/hang)
switch (m_current_matrix_mode) {
case GL_PROJECTION:
RETURN_WITH_ERROR_IF(m_projection_matrix_stack.size() == 0, GL_STACK_UNDERFLOW);
m_projection_matrix = m_projection_matrix_stack.take_last();
break;
case GL_MODELVIEW:
RETURN_WITH_ERROR_IF(m_model_view_matrix_stack.size() == 0, GL_STACK_UNDERFLOW);
m_model_view_matrix = m_model_view_matrix_stack.take_last();
break;
default:
dbgln_if(GL_DEBUG, "glPopMatrix(): Attempt to pop matrix with invalid matrix mode, {}", m_current_matrix_mode);
return;
}
}
void SoftwareGLContext::gl_rotate(GLdouble angle, GLdouble x, GLdouble y, GLdouble z)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_rotate, angle, x, y, z);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
FloatVector3 axis = { (float)x, (float)y, (float)z };
axis.normalize();
auto rotation_mat = Gfx::rotation_matrix(axis, static_cast<float>(angle * M_PI * 2 / 360));
if (m_current_matrix_mode == GL_MODELVIEW)
m_model_view_matrix = m_model_view_matrix * rotation_mat;
else if (m_current_matrix_mode == GL_PROJECTION)
m_projection_matrix = m_projection_matrix * rotation_mat;
}
void SoftwareGLContext::gl_scale(GLdouble x, GLdouble y, GLdouble z)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_scale, x, y, z);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
if (m_current_matrix_mode == GL_MODELVIEW) {
m_model_view_matrix = m_model_view_matrix * Gfx::scale_matrix(FloatVector3 { static_cast<float>(x), static_cast<float>(y), static_cast<float>(z) });
} else if (m_current_matrix_mode == GL_PROJECTION) {
m_projection_matrix = m_projection_matrix * Gfx::scale_matrix(FloatVector3 { static_cast<float>(x), static_cast<float>(y), static_cast<float>(z) });
}
}
void SoftwareGLContext::gl_translate(GLdouble x, GLdouble y, GLdouble z)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_translate, x, y, z);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
if (m_current_matrix_mode == GL_MODELVIEW) {
m_model_view_matrix = m_model_view_matrix * Gfx::translation_matrix(FloatVector3 { (float)x, (float)y, (float)z });
} else if (m_current_matrix_mode == GL_PROJECTION) {
m_projection_matrix = m_projection_matrix * Gfx::translation_matrix(FloatVector3 { (float)x, (float)y, (float)z });
}
}
void SoftwareGLContext::gl_vertex(GLdouble x, GLdouble y, GLdouble z, GLdouble w)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_vertex, x, y, z, w);
GLVertex vertex;
vertex.position = { static_cast<float>(x), static_cast<float>(y), static_cast<float>(z), static_cast<float>(w) };
vertex.color = m_current_vertex_color;
vertex.tex_coord = { m_current_vertex_tex_coord.x(), m_current_vertex_tex_coord.y() };
vertex_list.append(vertex);
}
// FIXME: We need to add `r` and `q` to our GLVertex?!
void SoftwareGLContext::gl_tex_coord(GLfloat s, GLfloat t, GLfloat r, GLfloat q)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_tex_coord, s, t, r, q);
m_current_vertex_tex_coord = { s, t, r, q };
}
void SoftwareGLContext::gl_viewport(GLint x, GLint y, GLsizei width, GLsizei height)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_viewport, x, y, width, height);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
(void)(x);
(void)(y);
(void)(width);
(void)(height);
}
void SoftwareGLContext::gl_enable(GLenum capability)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_enable, capability);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
auto rasterizer_options = m_rasterizer.options();
bool update_rasterizer_options = false;
switch (capability) {
case GL_CULL_FACE:
m_cull_faces = true;
break;
case GL_DEPTH_TEST:
m_depth_test_enabled = true;
rasterizer_options.enable_depth_test = true;
update_rasterizer_options = true;
break;
case GL_BLEND:
m_blend_enabled = true;
rasterizer_options.enable_blending = true;
update_rasterizer_options = true;
break;
case GL_ALPHA_TEST:
m_alpha_test_enabled = true;
rasterizer_options.enable_alpha_test = true;
update_rasterizer_options = true;
break;
default:
RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
}
if (update_rasterizer_options)
m_rasterizer.set_options(rasterizer_options);
}
void SoftwareGLContext::gl_disable(GLenum capability)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_disable, capability);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
auto rasterizer_options = m_rasterizer.options();
bool update_rasterizer_options = false;
switch (capability) {
case GL_CULL_FACE:
m_cull_faces = false;
break;
case GL_DEPTH_TEST:
m_depth_test_enabled = false;
rasterizer_options.enable_depth_test = false;
update_rasterizer_options = true;
break;
case GL_BLEND:
m_blend_enabled = false;
rasterizer_options.enable_blending = false;
update_rasterizer_options = true;
break;
case GL_ALPHA_TEST:
m_alpha_test_enabled = false;
rasterizer_options.enable_alpha_test = false;
update_rasterizer_options = true;
break;
default:
RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
}
if (update_rasterizer_options)
m_rasterizer.set_options(rasterizer_options);
}
void SoftwareGLContext::gl_gen_textures(GLsizei n, GLuint* textures)
{
RETURN_WITH_ERROR_IF(n < 0, GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
m_name_allocator.allocate(n, textures);
// Initialize all texture names with a nullptr
for (auto i = 0; i < n; i++) {
GLuint name = textures[i];
m_allocated_textures.set(name, nullptr);
}
}
void SoftwareGLContext::gl_delete_textures(GLsizei n, const GLuint* textures)
{
RETURN_WITH_ERROR_IF(n < 0, GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
m_name_allocator.free(n, textures);
for (auto i = 0; i < n; i++) {
GLuint name = textures[i];
auto texture_object = m_allocated_textures.find(name);
if (texture_object == m_allocated_textures.end() || texture_object->value.is_null())
continue;
// Check all texture units
for (auto& texture_unit : m_texture_units) {
if (texture_object->value == texture_unit.bound_texture())
texture_unit.unbind_texture(GL_TEXTURE_2D);
}
m_allocated_textures.remove(name);
}
}
void SoftwareGLContext::gl_tex_image_2d(GLenum target, GLint level, GLint internal_format, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const GLvoid* data)
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
// We only support GL_TEXTURE_2D for now
RETURN_WITH_ERROR_IF(target != GL_TEXTURE_2D, GL_INVALID_ENUM);
// Check if there is actually a texture bound
RETURN_WITH_ERROR_IF(target == GL_TEXTURE_2D && m_active_texture_unit->currently_bound_target() != GL_TEXTURE_2D, GL_INVALID_OPERATION);
// We only support symbolic constants for now
RETURN_WITH_ERROR_IF(!(internal_format == GL_RGB || internal_format == GL_RGBA), GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(type != GL_UNSIGNED_BYTE, GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF(level < 0 || level > Texture2D::LOG2_MAX_TEXTURE_SIZE, GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF(width < 0 || height < 0 || width > (2 + Texture2D::MAX_TEXTURE_SIZE) || height > (2 + Texture2D::MAX_TEXTURE_SIZE), GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF((width & 2) != 0 || (height & 2) != 0, GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF(border < 0 || border > 1, GL_INVALID_VALUE);
m_active_texture_unit->bound_texture_2d()->upload_texture_data(target, level, internal_format, width, height, border, format, type, data);
}
void SoftwareGLContext::gl_tex_parameter(GLenum target, GLenum pname, GLfloat param)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_tex_parameter, target, pname, param);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
// FIXME: We currently only support GL_TETXURE_2D targets. 1D, 3D and CUBE should also be supported (https://docs.gl/gl2/glTexParameter)
RETURN_WITH_ERROR_IF(target != GL_TEXTURE_2D, GL_INVALID_ENUM);
// FIXME: implement the remaining parameters. (https://docs.gl/gl2/glTexParameter)
RETURN_WITH_ERROR_IF(!(pname == GL_TEXTURE_MIN_FILTER
|| pname == GL_TEXTURE_MAG_FILTER
|| pname == GL_TEXTURE_WRAP_S
|| pname == GL_TEXTURE_WRAP_T),
GL_INVALID_ENUM);
if (target == GL_TEXTURE_2D) {
auto texture2d = m_active_texture_unit->bound_texture_2d();
if (texture2d.is_null())
return;
switch (pname) {
case GL_TEXTURE_MIN_FILTER:
RETURN_WITH_ERROR_IF(!(param == GL_NEAREST
|| param == GL_LINEAR
|| param == GL_NEAREST_MIPMAP_NEAREST
|| param == GL_LINEAR_MIPMAP_NEAREST
|| param == GL_NEAREST_MIPMAP_LINEAR
|| param == GL_LINEAR_MIPMAP_LINEAR),
GL_INVALID_ENUM);
texture2d->sampler().set_min_filter(param);
break;
case GL_TEXTURE_MAG_FILTER:
RETURN_WITH_ERROR_IF(!(param == GL_NEAREST
|| param == GL_LINEAR),
GL_INVALID_ENUM);
texture2d->sampler().set_mag_filter(param);
break;
case GL_TEXTURE_WRAP_S:
RETURN_WITH_ERROR_IF(!(param == GL_CLAMP
|| param == GL_CLAMP_TO_BORDER
|| param == GL_CLAMP_TO_EDGE
|| param == GL_MIRRORED_REPEAT
|| param == GL_REPEAT),
GL_INVALID_ENUM);
texture2d->sampler().set_wrap_s_mode(param);
break;
case GL_TEXTURE_WRAP_T:
RETURN_WITH_ERROR_IF(!(param == GL_CLAMP
|| param == GL_CLAMP_TO_BORDER
|| param == GL_CLAMP_TO_EDGE
|| param == GL_MIRRORED_REPEAT
|| param == GL_REPEAT),
GL_INVALID_ENUM);
texture2d->sampler().set_wrap_t_mode(param);
break;
default:
VERIFY_NOT_REACHED();
}
}
}
void SoftwareGLContext::gl_front_face(GLenum face)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_front_face, face);
RETURN_WITH_ERROR_IF(face < GL_CW || face > GL_CCW, GL_INVALID_ENUM);
m_front_face = face;
}
void SoftwareGLContext::gl_cull_face(GLenum cull_mode)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_cull_face, cull_mode);
RETURN_WITH_ERROR_IF(cull_mode < GL_FRONT || cull_mode > GL_FRONT_AND_BACK, GL_INVALID_ENUM);
m_culled_sides = cull_mode;
}
GLuint SoftwareGLContext::gl_gen_lists(GLsizei range)
{
RETURN_VALUE_WITH_ERROR_IF(range <= 0, GL_INVALID_VALUE, 0);
RETURN_VALUE_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION, 0);
auto initial_entry = m_listings.size();
m_listings.resize(range + initial_entry);
return initial_entry + 1;
}
void SoftwareGLContext::gl_call_list(GLuint list)
{
if (m_gl_call_depth > max_allowed_gl_call_depth)
return;
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_call_list, list);
if (m_listings.size() < list)
return;
TemporaryChange change { m_gl_call_depth, m_gl_call_depth + 1 };
auto& listing = m_listings[list - 1];
for (auto& entry : listing.entries) {
entry.function.visit([&](auto& function) {
entry.arguments.visit([&](auto& arguments) {
auto apply = [&]<typename... Args>(Args && ... args)
{
if constexpr (requires { (this->*function)(forward<Args>(args)...); })
(this->*function)(forward<Args>(args)...);
};
arguments.apply_as_args(apply);
});
});
}
}
void SoftwareGLContext::gl_delete_lists(GLuint list, GLsizei range)
{
if (m_listings.size() < list || m_listings.size() <= list + range)
return;
for (auto& entry : m_listings.span().slice(list - 1, range))
entry.entries.clear_with_capacity();
}
void SoftwareGLContext::gl_end_list()
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(!m_current_listing_index.has_value(), GL_INVALID_OPERATION);
m_listings[m_current_listing_index->index] = move(m_current_listing_index->listing);
m_current_listing_index.clear();
}
void SoftwareGLContext::gl_new_list(GLuint list, GLenum mode)
{
RETURN_WITH_ERROR_IF(list == 0, GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF(mode != GL_COMPILE && mode != GL_COMPILE_AND_EXECUTE, GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(m_current_listing_index.has_value(), GL_INVALID_OPERATION);
if (m_listings.size() < list)
return;
m_current_listing_index = CurrentListing { {}, static_cast<size_t>(list - 1), mode };
}
void SoftwareGLContext::gl_flush()
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
// No-op since SoftwareGLContext is completely synchronous at the moment
}
void SoftwareGLContext::gl_finish()
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
// No-op since SoftwareGLContext is completely synchronous at the moment
}
void SoftwareGLContext::gl_blend_func(GLenum src_factor, GLenum dst_factor)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_blend_func, src_factor, dst_factor);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
// FIXME: The list of allowed enums differs between API versions
// This was taken from the 2.0 spec on https://docs.gl/gl2/glBlendFunc
RETURN_WITH_ERROR_IF(!(src_factor == GL_ZERO
|| src_factor == GL_ONE
|| src_factor == GL_SRC_COLOR
|| src_factor == GL_ONE_MINUS_SRC_COLOR
|| src_factor == GL_DST_COLOR
|| src_factor == GL_ONE_MINUS_DST_COLOR
|| src_factor == GL_SRC_ALPHA
|| src_factor == GL_ONE_MINUS_SRC_ALPHA
|| src_factor == GL_DST_ALPHA
|| src_factor == GL_ONE_MINUS_DST_ALPHA
|| src_factor == GL_CONSTANT_COLOR
|| src_factor == GL_ONE_MINUS_CONSTANT_COLOR
|| src_factor == GL_CONSTANT_ALPHA
|| src_factor == GL_ONE_MINUS_CONSTANT_ALPHA
|| src_factor == GL_SRC_ALPHA_SATURATE),
GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(!(dst_factor == GL_ZERO
|| dst_factor == GL_ONE
|| dst_factor == GL_SRC_COLOR
|| dst_factor == GL_ONE_MINUS_SRC_COLOR
|| dst_factor == GL_DST_COLOR
|| dst_factor == GL_ONE_MINUS_DST_COLOR
|| dst_factor == GL_SRC_ALPHA
|| dst_factor == GL_ONE_MINUS_SRC_ALPHA
|| dst_factor == GL_DST_ALPHA
|| dst_factor == GL_ONE_MINUS_DST_ALPHA
|| dst_factor == GL_CONSTANT_COLOR
|| dst_factor == GL_ONE_MINUS_CONSTANT_COLOR
|| dst_factor == GL_CONSTANT_ALPHA
|| dst_factor == GL_ONE_MINUS_CONSTANT_ALPHA),
GL_INVALID_ENUM);
m_blend_source_factor = src_factor;
m_blend_destination_factor = dst_factor;
auto options = m_rasterizer.options();
options.blend_source_factor = m_blend_source_factor;
options.blend_destination_factor = m_blend_destination_factor;
m_rasterizer.set_options(options);
}
void SoftwareGLContext::gl_shade_model(GLenum mode)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_shade_model, mode);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(mode != GL_FLAT && mode != GL_SMOOTH, GL_INVALID_ENUM);
auto options = m_rasterizer.options();
options.shade_smooth = (mode == GL_SMOOTH);
m_rasterizer.set_options(options);
}
void SoftwareGLContext::gl_alpha_func(GLenum func, GLclampf ref)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_alpha_func, func, ref);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(func < GL_NEVER || func > GL_ALWAYS, GL_INVALID_ENUM);
m_alpha_test_func = func;
m_alpha_test_ref_value = ref;
auto options = m_rasterizer.options();
options.alpha_test_func = m_alpha_test_func;
options.alpha_test_ref_value = m_alpha_test_ref_value;
m_rasterizer.set_options(options);
}
void SoftwareGLContext::gl_hint(GLenum target, GLenum mode)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_hint, target, mode);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(target != GL_PERSPECTIVE_CORRECTION_HINT
&& target != GL_POINT_SMOOTH_HINT
&& target != GL_LINE_SMOOTH_HINT
&& target != GL_POLYGON_SMOOTH_HINT
&& target != GL_FOG_HINT
&& target != GL_GENERATE_MIPMAP_HINT
&& target != GL_TEXTURE_COMPRESSION_HINT,
GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(mode != GL_DONT_CARE
&& mode != GL_FASTEST
&& mode != GL_NICEST,
GL_INVALID_ENUM);
// According to the spec implementors are free to ignore glHint. So we do.
}
void SoftwareGLContext::gl_read_buffer(GLenum mode)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_read_buffer, mode);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
// FIXME: Also allow aux buffers GL_AUX0 through GL_AUX3 here
// plus any aux buffer between 0 and GL_AUX_BUFFERS
RETURN_WITH_ERROR_IF(mode != GL_FRONT_LEFT
&& mode != GL_FRONT_RIGHT
&& mode != GL_BACK_LEFT
&& mode != GL_BACK_RIGHT
&& mode != GL_FRONT
&& mode != GL_BACK
&& mode != GL_LEFT
&& mode != GL_RIGHT,
GL_INVALID_ENUM);
// FIXME: We do not currently have aux buffers, so make it an invalid
// operation to select anything but front or back buffers. Also we do
// not allow selecting the stereoscopic RIGHT buffers since we do not
// have them configured.
RETURN_WITH_ERROR_IF(mode != GL_FRONT_LEFT
&& mode != GL_FRONT
&& mode != GL_BACK_LEFT
&& mode != GL_BACK
&& mode != GL_FRONT
&& mode != GL_BACK
&& mode != GL_LEFT,
GL_INVALID_OPERATION);
m_current_read_buffer = mode;
}
void SoftwareGLContext::gl_read_pixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLvoid* pixels)
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(width < 0 || height < 0, GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF(format != GL_COLOR_INDEX
&& format != GL_STENCIL_INDEX
&& format != GL_DEPTH_COMPONENT
&& format != GL_RED
&& format != GL_GREEN
&& format != GL_BLUE
&& format != GL_ALPHA
&& format != GL_RGB
&& format != GL_RGBA
&& format != GL_LUMINANCE
&& format != GL_LUMINANCE_ALPHA,
GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(type != GL_UNSIGNED_BYTE
&& type != GL_BYTE
&& type != GL_BITMAP
&& type != GL_UNSIGNED_SHORT
&& type != GL_SHORT
&& type != GL_BLUE
&& type != GL_UNSIGNED_INT
&& type != GL_INT
&& type != GL_FLOAT,
GL_INVALID_ENUM);
// FIXME: We only support RGBA buffers for now.
// Once we add support for indexed color modes do the correct check here
RETURN_WITH_ERROR_IF(format == GL_COLOR_INDEX, GL_INVALID_OPERATION);
// FIXME: We do not have stencil buffers yet
// Once we add support for stencil buffers do the correct check here
RETURN_WITH_ERROR_IF(format == GL_STENCIL_INDEX, GL_INVALID_OPERATION);
if (format == GL_DEPTH_COMPONENT) {
// FIXME: This check needs to be a bit more sophisticated. Currently the buffers
// are hardcoded. Once we add proper structures for them we need to correct this check
// Error because only back buffer has a depth buffer
RETURN_WITH_ERROR_IF(m_current_read_buffer == GL_FRONT
|| m_current_read_buffer == GL_FRONT_LEFT
|| m_current_read_buffer == GL_FRONT_RIGHT,
GL_INVALID_OPERATION);
}
// Some helper functions for converting float values to integer types
auto float_to_i8 = [](float f) -> GLchar {
return static_cast<GLchar>((0x7f * min(max(f, 0.0f), 1.0f) - 1) / 2);
};
auto float_to_i16 = [](float f) -> GLshort {
return static_cast<GLshort>((0x7fff * min(max(f, 0.0f), 1.0f) - 1) / 2);
};
auto float_to_i32 = [](float f) -> GLint {
return static_cast<GLint>((0x7fffffff * min(max(f, 0.0f), 1.0f) - 1) / 2);
};
auto float_to_u8 = [](float f) -> GLubyte {
return static_cast<GLubyte>(0xff * min(max(f, 0.0f), 1.0f));
};
auto float_to_u16 = [](float f) -> GLushort {
return static_cast<GLushort>(0xffff * min(max(f, 0.0f), 1.0f));
};
auto float_to_u32 = [](float f) -> GLuint {
return static_cast<GLuint>(0xffffffff * min(max(f, 0.0f), 1.0f));
};
if (format == GL_DEPTH_COMPONENT) {
// Read from depth buffer
for (GLsizei i = 0; i < height; ++i) {
for (GLsizei j = 0; j < width; ++j) {
float depth = m_rasterizer.get_depthbuffer_value(x + j, y + i);
switch (type) {
case GL_BYTE:
reinterpret_cast<GLchar*>(pixels)[i * width + j] = float_to_i8(depth);
break;
case GL_SHORT:
reinterpret_cast<GLshort*>(pixels)[i * width + j] = float_to_i16(depth);
break;
case GL_INT:
reinterpret_cast<GLint*>(pixels)[i * width + j] = float_to_i32(depth);
break;
case GL_UNSIGNED_BYTE:
reinterpret_cast<GLubyte*>(pixels)[i * width + j] = float_to_u8(depth);
break;
case GL_UNSIGNED_SHORT:
reinterpret_cast<GLushort*>(pixels)[i * width + j] = float_to_u16(depth);
break;
case GL_UNSIGNED_INT:
reinterpret_cast<GLuint*>(pixels)[i * width + j] = float_to_u32(depth);
break;
case GL_FLOAT:
reinterpret_cast<GLfloat*>(pixels)[i * width + j] = min(max(depth, 0.0f), 1.0f);
break;
}
}
}
return;
}
bool write_red = false;
bool write_green = false;
bool write_blue = false;
bool write_alpha = false;
size_t component_count = 0;
size_t component_size = 0;
size_t red_offset = 0;
size_t green_offset = 0;
size_t blue_offset = 0;
size_t alpha_offset = 0;
char* red_ptr = nullptr;
char* green_ptr = nullptr;
char* blue_ptr = nullptr;
char* alpha_ptr = nullptr;
switch (format) {
case GL_RGB:
write_red = true;
write_green = true;
write_blue = true;
component_count = 3;
red_offset = 2;
green_offset = 1;
blue_offset = 0;
break;
case GL_RGBA:
write_red = true;
write_green = true;
write_blue = true;
write_alpha = true;
component_count = 4;
red_offset = 3;
green_offset = 2;
blue_offset = 1;
alpha_offset = 0;
break;
case GL_RED:
write_red = true;
component_count = 1;
red_offset = 0;
break;
case GL_GREEN:
write_green = true;
component_count = 1;
green_offset = 0;
break;
case GL_BLUE:
write_blue = true;
component_count = 1;
blue_offset = 0;
break;
case GL_ALPHA:
write_alpha = true;
component_count = 1;
alpha_offset = 0;
break;
}
switch (type) {
case GL_BYTE:
case GL_UNSIGNED_BYTE:
component_size = 1;
break;
case GL_SHORT:
case GL_UNSIGNED_SHORT:
component_size = 2;
break;
case GL_INT:
case GL_UNSIGNED_INT:
case GL_FLOAT:
component_size = 4;
break;
}
char* out_ptr = reinterpret_cast<char*>(pixels);
for (int i = 0; i < (int)height; ++i) {
for (int j = 0; j < (int)width; ++j) {
Gfx::RGBA32 color {};
if (m_current_read_buffer == GL_FRONT || m_current_read_buffer == GL_LEFT || m_current_read_buffer == GL_FRONT_LEFT) {
if (y + i >= m_frontbuffer->width() || x + j >= m_frontbuffer->height())
color = 0;
else
color = m_frontbuffer->scanline(y + i)[x + j];
} else {
color = m_rasterizer.get_backbuffer_pixel(x + j, y + i);
}
float red = ((color >> 24) & 0xff) / 255.0f;
float green = ((color >> 16) & 0xff) / 255.0f;
float blue = ((color >> 8) & 0xff) / 255.0f;
float alpha = (color & 0xff) / 255.0f;
// FIXME: Set up write pointers based on selected endianness (glPixelStore)
red_ptr = out_ptr + (component_size * red_offset);
green_ptr = out_ptr + (component_size * green_offset);
blue_ptr = out_ptr + (component_size * blue_offset);
alpha_ptr = out_ptr + (component_size * alpha_offset);
switch (type) {
case GL_BYTE:
if (write_red)
*reinterpret_cast<GLchar*>(red_ptr) = float_to_i8(red);
if (write_green)
*reinterpret_cast<GLchar*>(green_ptr) = float_to_i8(green);
if (write_blue)
*reinterpret_cast<GLchar*>(blue_ptr) = float_to_i8(blue);
if (write_alpha)
*reinterpret_cast<GLchar*>(alpha_ptr) = float_to_i8(alpha);
break;
case GL_UNSIGNED_BYTE:
if (write_red)
*reinterpret_cast<GLubyte*>(red_ptr) = float_to_u8(red);
if (write_green)
*reinterpret_cast<GLubyte*>(green_ptr) = float_to_u8(green);
if (write_blue)
*reinterpret_cast<GLubyte*>(blue_ptr) = float_to_u8(blue);
if (write_alpha)
*reinterpret_cast<GLubyte*>(alpha_ptr) = float_to_u8(alpha);
break;
case GL_SHORT:
if (write_red)
*reinterpret_cast<GLshort*>(red_ptr) = float_to_i16(red);
if (write_green)
*reinterpret_cast<GLshort*>(green_ptr) = float_to_i16(green);
if (write_blue)
*reinterpret_cast<GLshort*>(blue_ptr) = float_to_i16(blue);
if (write_alpha)
*reinterpret_cast<GLshort*>(alpha_ptr) = float_to_i16(alpha);
break;
case GL_UNSIGNED_SHORT:
if (write_red)
*reinterpret_cast<GLushort*>(red_ptr) = float_to_u16(red);
if (write_green)
*reinterpret_cast<GLushort*>(green_ptr) = float_to_u16(green);
if (write_blue)
*reinterpret_cast<GLushort*>(blue_ptr) = float_to_u16(blue);
if (write_alpha)
*reinterpret_cast<GLushort*>(alpha_ptr) = float_to_u16(alpha);
break;
case GL_INT:
if (write_red)
*reinterpret_cast<GLint*>(red_ptr) = float_to_i32(red);
if (write_green)
*reinterpret_cast<GLint*>(green_ptr) = float_to_i32(green);
if (write_blue)
*reinterpret_cast<GLint*>(blue_ptr) = float_to_i32(blue);
if (write_alpha)
*reinterpret_cast<GLint*>(alpha_ptr) = float_to_i32(alpha);
break;
case GL_UNSIGNED_INT:
if (write_red)
*reinterpret_cast<GLuint*>(red_ptr) = float_to_u32(red);
if (write_green)
*reinterpret_cast<GLuint*>(green_ptr) = float_to_u32(green);
if (write_blue)
*reinterpret_cast<GLuint*>(blue_ptr) = float_to_u32(blue);
if (write_alpha)
*reinterpret_cast<GLuint*>(alpha_ptr) = float_to_u32(alpha);
break;
case GL_FLOAT:
if (write_red)
*reinterpret_cast<GLfloat*>(red_ptr) = min(max(red, 0.0f), 1.0f);
if (write_green)
*reinterpret_cast<GLfloat*>(green_ptr) = min(max(green, 0.0f), 1.0f);
if (write_blue)
*reinterpret_cast<GLfloat*>(blue_ptr) = min(max(blue, 0.0f), 1.0f);
if (write_alpha)
*reinterpret_cast<GLfloat*>(alpha_ptr) = min(max(alpha, 0.0f), 1.0f);
break;
}
out_ptr += component_size * component_count;
}
}
}
void SoftwareGLContext::gl_bind_texture(GLenum target, GLuint texture)
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
// FIXME: We only support GL_TEXTURE_2D for now
RETURN_WITH_ERROR_IF(target != GL_TEXTURE_2D, GL_INVALID_ENUM);
if (texture == 0) {
switch (target) {
case GL_TEXTURE_2D:
m_active_texture_unit->unbind_texture(target);
return;
default:
VERIFY_NOT_REACHED();
return;
}
}
auto it = m_allocated_textures.find(texture);
// The texture name does not exist
RETURN_WITH_ERROR_IF(it == m_allocated_textures.end(), GL_INVALID_VALUE);
auto texture_object = it->value;
// Binding a texture to a different target than it was first bound is an invalid operation
// FIXME: We only support GL_TEXTURE_2D for now
RETURN_WITH_ERROR_IF(target == GL_TEXTURE_2D && !texture_object.is_null() && !texture_object->is_texture_2d(), GL_INVALID_OPERATION);
if (!texture_object) {
// This is the first time the texture is bound. Allocate an actual texture object
switch (target) {
case GL_TEXTURE_2D:
texture_object = adopt_ref(*new Texture2D());
break;
default:
VERIFY_NOT_REACHED();
break;
}
m_allocated_textures.set(texture, texture_object);
}
switch (target) {
case GL_TEXTURE_2D:
m_active_texture_unit->bind_texture_to_target(target, texture_object);
break;
}
}
void SoftwareGLContext::gl_active_texture(GLenum texture)
{
RETURN_WITH_ERROR_IF(texture < GL_TEXTURE0 || texture > GL_TEXTURE31, GL_INVALID_ENUM);
m_active_texture_unit = &m_texture_units.at(texture - GL_TEXTURE0);
}
void SoftwareGLContext::gl_get_floatv(GLenum pname, GLfloat* params)
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
auto flatten_and_assign_matrix = [&params](const FloatMatrix4x4& matrix) {
auto elements = matrix.elements();
for (size_t i = 0; i < 4; ++i) {
for (size_t j = 0; j < 4; ++j) {
params[i * 4 + j] = elements[i][j];
}
}
};
switch (pname) {
case GL_MODELVIEW_MATRIX:
if (m_current_matrix_mode == GL_MODELVIEW)
flatten_and_assign_matrix(m_model_view_matrix);
else {
if (m_model_view_matrix_stack.is_empty())
flatten_and_assign_matrix(FloatMatrix4x4::identity());
else
flatten_and_assign_matrix(m_model_view_matrix_stack.last());
}
break;
default:
// FIXME: Because glQuake only requires GL_MODELVIEW_MATRIX, that is the only parameter
// that we currently support. More parameters should be supported.
TODO();
}
}
void SoftwareGLContext::gl_get_booleanv(GLenum pname, GLboolean* data)
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
switch (pname) {
case GL_BLEND:
*data = m_blend_enabled ? GL_TRUE : GL_FALSE;
break;
case GL_ALPHA_TEST:
*data = m_alpha_test_func ? GL_TRUE : GL_FALSE;
break;
case GL_DEPTH_TEST:
*data = m_depth_test_enabled ? GL_TRUE : GL_FALSE;
break;
case GL_CULL_FACE:
*data = m_cull_faces ? GL_TRUE : GL_FALSE;
break;
default:
// According to the Khronos docs, we always return GL_INVALID_ENUM if we encounter a non-accepted value
// for `pname`
RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
}
}
void SoftwareGLContext::gl_get_integerv(GLenum pname, GLint* data)
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
switch (pname) {
case GL_BLEND_SRC_ALPHA:
*data = m_blend_source_factor;
break;
case GL_BLEND_DST_ALPHA:
*data = m_blend_destination_factor;
break;
default:
// According to the Khronos docs, we always return GL_INVALID_ENUM if we encounter a non-accepted value
// for `pname`
RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
}
}
void SoftwareGLContext::gl_depth_mask(GLboolean flag)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_depth_mask, flag);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
auto options = m_rasterizer.options();
options.enable_depth_write = (flag != GL_FALSE);
m_rasterizer.set_options(options);
}
void SoftwareGLContext::gl_enable_client_state(GLenum cap)
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
switch (cap) {
case GL_VERTEX_ARRAY:
m_client_side_vertex_array_enabled = true;
break;
case GL_COLOR_ARRAY:
m_client_side_color_array_enabled = true;
break;
case GL_TEXTURE_COORD_ARRAY:
m_client_side_texture_coord_array_enabled = true;
break;
default:
RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
}
}
void SoftwareGLContext::gl_disable_client_state(GLenum cap)
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
switch (cap) {
case GL_VERTEX_ARRAY:
m_client_side_vertex_array_enabled = false;
break;
case GL_COLOR_ARRAY:
m_client_side_color_array_enabled = false;
break;
case GL_TEXTURE_COORD_ARRAY:
m_client_side_texture_coord_array_enabled = false;
break;
default:
RETURN_WITH_ERROR_IF(true, GL_INVALID_ENUM);
}
}
void SoftwareGLContext::gl_vertex_pointer(GLint size, GLenum type, GLsizei stride, const void* pointer)
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(!(size == 2 || size == 3 || size == 4), GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF(!(type == GL_SHORT || type == GL_INT || type == GL_FLOAT || type == GL_DOUBLE), GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(stride < 0, GL_INVALID_VALUE);
m_client_vertex_pointer.size = size;
m_client_vertex_pointer.type = type;
m_client_vertex_pointer.stride = stride;
m_client_vertex_pointer.pointer = pointer;
}
void SoftwareGLContext::gl_color_pointer(GLint size, GLenum type, GLsizei stride, const void* pointer)
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(!(size == 3 || size == 4), GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF(!(type == GL_BYTE
|| type == GL_UNSIGNED_BYTE
|| type == GL_SHORT
|| type == GL_UNSIGNED_SHORT
|| type == GL_INT
|| type == GL_UNSIGNED_INT
|| type == GL_FLOAT
|| type == GL_DOUBLE),
GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(stride < 0, GL_INVALID_VALUE);
m_client_color_pointer.size = size;
m_client_color_pointer.type = type;
m_client_color_pointer.stride = stride;
m_client_color_pointer.pointer = pointer;
}
void SoftwareGLContext::gl_tex_coord_pointer(GLint size, GLenum type, GLsizei stride, const void* pointer)
{
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(!(size == 1 || size == 2 || size == 3 || size == 4), GL_INVALID_VALUE);
RETURN_WITH_ERROR_IF(!(type == GL_SHORT || type == GL_INT || type == GL_FLOAT || type == GL_DOUBLE), GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(stride < 0, GL_INVALID_VALUE);
m_client_tex_coord_pointer.size = size;
m_client_tex_coord_pointer.type = type;
m_client_tex_coord_pointer.stride = stride;
m_client_tex_coord_pointer.pointer = pointer;
}
void SoftwareGLContext::gl_draw_arrays(GLenum mode, GLint first, GLsizei count)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_draw_arrays, mode, first, count);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
// FIXME: Some modes are still missing (GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES,GL_QUAD_STRIP)
RETURN_WITH_ERROR_IF(!(mode == GL_TRIANGLE_STRIP
|| mode == GL_TRIANGLE_FAN
|| mode == GL_TRIANGLES
|| mode == GL_QUADS
|| mode == GL_POLYGON),
GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(count < 0, GL_INVALID_VALUE);
// At least the vertex array needs to be enabled
if (!m_client_side_vertex_array_enabled)
return;
auto last = first + count;
glBegin(mode);
for (int i = first; i < last; i++) {
if (m_client_side_texture_coord_array_enabled) {
float tex_coords[4] { 0, 0, 0, 0 };
read_from_vertex_attribute_pointer(m_client_tex_coord_pointer, i, tex_coords, false);
glTexCoord4fv(tex_coords);
}
if (m_client_side_color_array_enabled) {
float color[4] { 0, 0, 0, 1 };
read_from_vertex_attribute_pointer(m_client_color_pointer, i, color, true);
glColor4fv(color);
}
float vertex[4] { 0, 0, 0, 1 };
read_from_vertex_attribute_pointer(m_client_vertex_pointer, i, vertex, false);
glVertex4fv(vertex);
}
glEnd();
}
void SoftwareGLContext::gl_draw_elements(GLenum mode, GLsizei count, GLenum type, const void* indices)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_draw_elements, mode, count, type, indices);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
// FIXME: Some modes are still missing (GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES,GL_QUAD_STRIP)
RETURN_WITH_ERROR_IF(!(mode == GL_TRIANGLE_STRIP
|| mode == GL_TRIANGLE_FAN
|| mode == GL_TRIANGLES
|| mode == GL_QUADS
|| mode == GL_POLYGON),
GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(!(type == GL_UNSIGNED_BYTE
|| type == GL_UNSIGNED_SHORT
|| type == GL_UNSIGNED_INT),
GL_INVALID_ENUM);
RETURN_WITH_ERROR_IF(count < 0, GL_INVALID_VALUE);
// At least the vertex array needs to be enabled
if (!m_client_side_vertex_array_enabled)
return;
glBegin(mode);
for (int index = 0; index < count; index++) {
int i = 0;
switch (type) {
case GL_UNSIGNED_BYTE:
i = reinterpret_cast<const GLubyte*>(indices)[index];
break;
case GL_UNSIGNED_SHORT:
i = reinterpret_cast<const GLushort*>(indices)[index];
break;
case GL_UNSIGNED_INT:
i = reinterpret_cast<const GLuint*>(indices)[index];
break;
}
if (m_client_side_texture_coord_array_enabled) {
float tex_coords[4] { 0, 0, 0, 0 };
read_from_vertex_attribute_pointer(m_client_tex_coord_pointer, i, tex_coords, false);
glTexCoord4fv(tex_coords);
}
if (m_client_side_color_array_enabled) {
float color[4] { 0, 0, 0, 1 };
read_from_vertex_attribute_pointer(m_client_color_pointer, i, color, true);
glColor4fv(color);
}
float vertex[4] { 0, 0, 0, 1 };
read_from_vertex_attribute_pointer(m_client_vertex_pointer, i, vertex, false);
glVertex4fv(vertex);
}
glEnd();
}
void SoftwareGLContext::gl_depth_range(GLdouble min, GLdouble max)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_depth_range, min, max);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
auto options = m_rasterizer.options();
options.depth_min = clamp(min, 0.f, 1.f);
options.depth_max = clamp(max, 0.f, 1.f);
m_rasterizer.set_options(options);
}
void SoftwareGLContext::gl_depth_func(GLenum func)
{
APPEND_TO_CALL_LIST_AND_RETURN_IF_NEEDED(gl_depth_func, func);
RETURN_WITH_ERROR_IF(m_in_draw_state, GL_INVALID_OPERATION);
RETURN_WITH_ERROR_IF(!(func == GL_NEVER
|| func == GL_LESS
|| func == GL_EQUAL
|| func == GL_LEQUAL
|| func == GL_GREATER
|| func == GL_NOTEQUAL
|| func == GL_GEQUAL
|| func == GL_ALWAYS),
GL_INVALID_ENUM);
auto options = m_rasterizer.options();
options.depth_func = func;
m_rasterizer.set_options(options);
}
// General helper function to read arbitrary vertex attribute data into a float array
void SoftwareGLContext::read_from_vertex_attribute_pointer(VertexAttribPointer const& attrib, int index, float* elements, bool normalize)
{
auto byte_ptr = reinterpret_cast<const char*>(attrib.pointer);
size_t stride = attrib.stride;
switch (attrib.type) {
case GL_BYTE: {
if (stride == 0)
stride = sizeof(GLbyte) * attrib.size;
for (int i = 0; i < attrib.size; i++) {
elements[i] = *(reinterpret_cast<const GLbyte*>(byte_ptr + stride * index) + i);
if (normalize)
elements[i] /= 0x80;
}
break;
}
case GL_UNSIGNED_BYTE: {
if (stride == 0)
stride = sizeof(GLubyte) * attrib.size;
for (int i = 0; i < attrib.size; i++) {
elements[i] = *(reinterpret_cast<const GLubyte*>(byte_ptr + stride * index) + i);
if (normalize)
elements[i] /= 0xff;
}
break;
}
case GL_SHORT: {
if (stride == 0)
stride = sizeof(GLshort) * attrib.size;
for (int i = 0; i < attrib.size; i++) {
elements[i] = *(reinterpret_cast<const GLshort*>(byte_ptr + stride * index) + i);
if (normalize)
elements[i] /= 0x8000;
}
break;
}
case GL_UNSIGNED_SHORT: {
if (stride == 0)
stride = sizeof(GLushort) * attrib.size;
for (int i = 0; i < attrib.size; i++) {
elements[i] = *(reinterpret_cast<const GLushort*>(byte_ptr + stride * index) + i);
if (normalize)
elements[i] /= 0xffff;
}
break;
}
case GL_INT: {
if (stride == 0)
stride = sizeof(GLint) * attrib.size;
for (int i = 0; i < attrib.size; i++) {
elements[i] = *(reinterpret_cast<const GLint*>(byte_ptr + stride * index) + i);
if (normalize)
elements[i] /= 0x80000000;
}
break;
}
case GL_UNSIGNED_INT: {
if (stride == 0)
stride = sizeof(GLuint) * attrib.size;
for (int i = 0; i < attrib.size; i++) {
elements[i] = *(reinterpret_cast<const GLuint*>(byte_ptr + stride * index) + i);
if (normalize)
elements[i] /= 0xffffffff;
}
break;
}
case GL_FLOAT: {
if (stride == 0)
stride = sizeof(GLfloat) * attrib.size;
for (int i = 0; i < attrib.size; i++) {
elements[i] = *(reinterpret_cast<const GLfloat*>(byte_ptr + stride * index) + i);
}
break;
}
case GL_DOUBLE: {
if (stride == 0)
stride = sizeof(GLdouble) * attrib.size;
for (int i = 0; i < attrib.size; i++) {
elements[i] = static_cast<float>(*(reinterpret_cast<const GLdouble*>(byte_ptr + stride * index) + i));
}
break;
}
}
}
void SoftwareGLContext::gl_color_mask(GLboolean red, GLboolean green, GLboolean blue, GLboolean alpha)
{
auto options = m_rasterizer.options();
auto mask = options.color_mask;
if (!red)
mask &= ~0x000000ff;
else
mask |= 0x000000ff;
if (!green)
mask &= ~0x0000ff00;
else
mask |= 0x0000ff00;
if (!blue)
mask &= ~0x00ff0000;
else
mask |= 0x00ff0000;
if (!alpha)
mask &= ~0xff000000;
else
mask |= 0xff000000;
options.color_mask = mask;
m_rasterizer.set_options(options);
}
void SoftwareGLContext::present()
{
m_rasterizer.blit_to(*m_frontbuffer);
}
}
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