ladybird/Userland/Libraries/LibGL/Tex/Texture.cpp
Jesse Buhagiar 4f324ba4d7 LibGL: Implement Texture State Management
Some very primitive Texture State management. Data can now be
uploaded to textures.
2021-05-26 16:36:53 +04:30

135 lines
4.4 KiB
C++

/*
* Copyright (c) 2021, Jesse Buhagiar <jooster669@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Format.h>
#include <LibGL/GL/gl.h>
#include <LibGL/Tex/Texture.h>
#include <string.h>
namespace GL {
void Texture::upload_texture_data(GLenum, GLint lod, GLint internal_format, GLsizei width, GLsizei height, GLint, GLenum format, GLenum, const GLvoid* pixels)
{
// NOTE: Some target, format, and internal formats are currently unsupported.
// Considering we control this library, and `gl.h` itself, we don't need to add any
// checks here to see if we support them; the program will simply fail to compile..
// Somebody passed us in nullptr...
// Apparently this allocates memory on the GPU (according to Khronos docs..)?
if (pixels == nullptr) {
dbgln("LibGL: pixels == nullptr when uploading texture data.");
VERIFY_NOT_REACHED();
}
m_internal_format = internal_format;
// Get reference to the mip
auto& mip = m_mipmaps[lod];
const u8* pixel_byte_array = reinterpret_cast<const u8*>(pixels);
// Copy pixel data to storage
// Pixels are already 32-bits wide
if (format == GL_RGBA || format == GL_BGRA) {
mip.pixel_data().resize(width * height * sizeof(u32));
memcpy(mip.pixel_data().data(), pixels, width * height * sizeof(u32));
} else {
mip.pixel_data().resize(width * height * 3);
// Copy RGB or BGR pixel data
for (auto i = 0; i < width * height * 3; i += 3) {
u32 b0 = pixel_byte_array[i]; // B or R
u32 b1 = pixel_byte_array[i + 1]; // G
u32 b2 = pixel_byte_array[i + 2]; // R or B
u32 pixel = ((0xffu << 24) | (b0 << 16) | (b1 << 8) | b2);
mip.pixel_data().append(pixel);
}
}
// Now we need to swizzle the texture data from `format` to `internal_format`
switch (format) {
case GL_BGR: {
if (internal_format == GL_RGB) {
swizzle(mip.pixel_data(), [](u32 pixel) -> u32 {
u8 r = pixel & 0xff;
u8 g = (pixel >> 8) & 0xff;
u8 b = (pixel >> 16) & 0xff;
return (0xff << 24) | (r << 16) | (g << 8) | b;
});
} else if (internal_format == GL_RGBA) {
swizzle(mip.pixel_data(), [](u32 pixel) -> u32 {
u8 r = pixel & 0xff;
u8 g = (pixel >> 8) & 0xff;
u8 b = (pixel >> 16) & 0xff;
return (r << 24) | (g << 16) | (b << 8) | 0xff;
});
}
} break;
case GL_BGRA: {
if (internal_format == GL_RGB) {
swizzle(mip.pixel_data(), [](u32 pixel) -> u32 {
u8 r = (pixel >> 8) & 0xff;
u8 g = (pixel >> 16) & 0xff;
u8 b = (pixel >> 24) & 0xff;
return (0xff << 24) | (r << 16) | (g << 8) | b;
});
} else if (internal_format == GL_RGBA) {
swizzle(mip.pixel_data(), [](u32 pixel) -> u32 {
u8 a = pixel & 0xff;
u8 r = (pixel >> 8) & 0xff;
u8 g = (pixel >> 16) & 0xff;
u8 b = (pixel >> 24) & 0xff;
return (r << 24) | (g << 16) | (b << 8) | a;
});
}
} break;
case GL_RGB: {
if (internal_format == GL_RGBA) {
swizzle(mip.pixel_data(), [](u32 pixel) -> u32 {
u8 r = pixel & 0xff;
u8 g = (pixel >> 8) & 0xff;
u8 b = (pixel >> 16) & 0xff;
return (r << 24) | (g << 16) | (b << 8) | 0xff;
});
}
} break;
case GL_RGBA:
break;
default:
// Let's crash for now so we can implement format by format
VERIFY_NOT_REACHED();
}
mip.set_width(width);
mip.set_height(height);
}
FloatVector4 Texture::sample_texel(const FloatVector2& uv) const
{
auto& mip = m_mipmaps.at(0);
// FIXME: Remove this to prevent a crash when we have proper texture binding
if (mip.width() == 0 || mip.height() == 0)
return { 1.0f, 1.0f, 1.0f, 1.0f };
u32 u = static_cast<u32>(uv.x() * mip.width());
u32 v = static_cast<u32>(uv.y() * mip.height());
u32 pixel = mip.pixel_data().at(v * mip.width() + u);
float b0 = ((pixel)&0xff) / 255.0f;
float b1 = ((pixel >> 8) & 0xff) / 255.0f;
float b2 = ((pixel >> 16) & 0xff) / 255.0f;
return { b0, b1, b2, 1.0f };
}
}