PICA: Properly emulate 1-stage delay in the combiner buffer

This was discovered and verified by @fincs. The tev combiner buffer
actually lags behind by one stage, meaning stage 1 reads the initial
color, stage 2 reads stage 0's output, and so on.

Fixes character portraits in Fire Emblem: Awakening and world textures
in Zelda: ALBW. Closes #1140.
This commit is contained in:
Yuri Kunde Schlesner 2015-11-30 22:33:38 -08:00
parent bec9049597
commit e9c209ccc8
2 changed files with 19 additions and 12 deletions

View file

@ -498,7 +498,8 @@ static void ProcessTriangleInternal(const Shader::OutputVertex& v0,
// with some basic arithmetic. Alpha combiners can be configured separately but work
// analogously.
Math::Vec4<u8> combiner_output;
Math::Vec4<u8> combiner_buffer = {
Math::Vec4<u8> combiner_buffer = {0, 0, 0, 0};
Math::Vec4<u8> next_combiner_buffer = {
regs.tev_combiner_buffer_color.r, regs.tev_combiner_buffer_color.g,
regs.tev_combiner_buffer_color.b, regs.tev_combiner_buffer_color.a
};
@ -747,14 +748,16 @@ static void ProcessTriangleInternal(const Shader::OutputVertex& v0,
combiner_output[2] = std::min((unsigned)255, color_output.b() * tev_stage.GetColorMultiplier());
combiner_output[3] = std::min((unsigned)255, alpha_output * tev_stage.GetAlphaMultiplier());
combiner_buffer = next_combiner_buffer;
if (regs.tev_combiner_buffer_input.TevStageUpdatesCombinerBufferColor(tev_stage_index)) {
combiner_buffer.r() = combiner_output.r();
combiner_buffer.g() = combiner_output.g();
combiner_buffer.b() = combiner_output.b();
next_combiner_buffer.r() = combiner_output.r();
next_combiner_buffer.g() = combiner_output.g();
next_combiner_buffer.b() = combiner_output.b();
}
if (regs.tev_combiner_buffer_input.TevStageUpdatesCombinerBufferAlpha(tev_stage_index)) {
combiner_buffer.a() = combiner_output.a();
next_combiner_buffer.a() = combiner_output.a();
}
}