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Pica/Rasterizer: Implement alpha blending.

This commit is contained in:
Tony Wasserka 2014-12-21 03:00:25 +01:00
parent e229ff8c83
commit a7ae0330b1

View file

@ -25,6 +25,18 @@ static void DrawPixel(int x, int y, const Math::Vec4<u8>& color) {
*(color_buffer + x + y * registers.framebuffer.GetWidth()) = value;
}
static const Math::Vec4<u8> GetPixel(int x, int y) {
u32* color_buffer_u32 = reinterpret_cast<u32*>(Memory::GetPointer(PAddrToVAddr(registers.framebuffer.GetColorBufferPhysicalAddress())));
u32 value = *(color_buffer_u32 + x + y * registers.framebuffer.GetWidth());
Math::Vec4<u8> ret;
ret.a() = value >> 24;
ret.r() = (value >> 16) & 0xFF;
ret.g() = (value >> 8) & 0xFF;
ret.b() = value & 0xFF;
return ret;
}
static u32 GetDepth(int x, int y) {
u16* depth_buffer = reinterpret_cast<u16*>(Memory::GetPointer(PAddrToVAddr(registers.framebuffer.GetDepthBufferPhysicalAddress())));
@ -430,6 +442,78 @@ void ProcessTriangle(const VertexShader::OutputVertex& v0,
SetDepth(x >> 4, y >> 4, z);
}
auto dest = GetPixel(x >> 4, y >> 4);
if (registers.output_merger.alphablend_enable) {
auto params = registers.output_merger.alpha_blending;
auto LookupFactorRGB = [&](decltype(params)::BlendFactor factor) -> Math::Vec3<u8> {
switch(factor) {
case params.Zero:
return Math::Vec3<u8>(0, 0, 0);
case params.One:
return Math::Vec3<u8>(255, 255, 255);
case params.SourceAlpha:
return Math::MakeVec(combiner_output.a(), combiner_output.a(), combiner_output.a());
case params.OneMinusSourceAlpha:
return Math::Vec3<u8>(255-combiner_output.a(), 255-combiner_output.a(), 255-combiner_output.a());
default:
LOG_CRITICAL(HW_GPU, "Unknown color blend factor %x", factor);
exit(0);
break;
}
};
auto LookupFactorA = [&](decltype(params)::BlendFactor factor) -> u8 {
switch(factor) {
case params.Zero:
return 0;
case params.One:
return 255;
case params.SourceAlpha:
return combiner_output.a();
case params.OneMinusSourceAlpha:
return 255 - combiner_output.a();
default:
LOG_CRITICAL(HW_GPU, "Unknown alpha blend factor %x", factor);
exit(0);
break;
}
};
auto srcfactor = Math::MakeVec(LookupFactorRGB(params.factor_source_rgb),
LookupFactorA(params.factor_source_a));
auto dstfactor = Math::MakeVec(LookupFactorRGB(params.factor_dest_rgb),
LookupFactorA(params.factor_dest_a));
switch (params.blend_equation_rgb) {
case params.Add:
{
auto result = (combiner_output * srcfactor + dest * dstfactor) / 255;
result.r() = std::min(255, result.r());
result.g() = std::min(255, result.g());
result.b() = std::min(255, result.b());
combiner_output = result.Cast<u8>();
break;
}
default:
LOG_CRITICAL(HW_GPU, "Unknown RGB blend equation %x", params.blend_equation_rgb.Value());
exit(0);
}
} else {
LOG_CRITICAL(HW_GPU, "logic op: %x", registers.output_merger.logic_op);
exit(0);
}
DrawPixel(x >> 4, y >> 4, combiner_output);
}
}