From e9c209ccc8ec8800306aa49b9b805f9d502d0a7e Mon Sep 17 00:00:00 2001
From: Yuri Kunde Schlesner <yuriks@yuriks.net>
Date: Mon, 30 Nov 2015 22:33:38 -0800
Subject: [PATCH] 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.
---
src/video_core/rasterizer.cpp | 13 ++++++++-----
.../renderer_opengl/gl_shader_gen.cpp | 18 +++++++++++-------
2 files changed, 19 insertions(+), 12 deletions(-)
diff --git a/src/video_core/rasterizer.cpp b/src/video_core/rasterizer.cpp
index 226fad7834..ecfdbc9e85 100644
--- a/src/video_core/rasterizer.cpp
+++ b/src/video_core/rasterizer.cpp
@@ -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();
}
}
diff --git a/src/video_core/renderer_opengl/gl_shader_gen.cpp b/src/video_core/renderer_opengl/gl_shader_gen.cpp
index 5268340cfc..498c506e7b 100644
--- a/src/video_core/renderer_opengl/gl_shader_gen.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_gen.cpp
@@ -311,11 +311,13 @@ static void WriteTevStage(std::string& out, const PicaShaderConfig& config, unsi
"clamp(alpha_output_" + index_name + " * " + std::to_string(stage.GetAlphaMultiplier()) + ".0, 0.0, 1.0));\n";
}
+ out += "combiner_buffer = next_combiner_buffer;\n";
+
if (config.TevStageUpdatesCombinerBufferColor(index))
- out += "combiner_buffer.rgb = last_tex_env_out.rgb;\n";
+ out += "next_combiner_buffer.rgb = last_tex_env_out.rgb;\n";
if (config.TevStageUpdatesCombinerBufferAlpha(index))
- out += "combiner_buffer.a = last_tex_env_out.a;\n";
+ out += "next_combiner_buffer.a = last_tex_env_out.a;\n";
}
std::string GenerateFragmentShader(const PicaShaderConfig& config) {
@@ -334,12 +336,10 @@ layout (std140) uniform shader_data {
int alphatest_ref;
};
-)";
+uniform sampler2D tex[3];
- out += "uniform sampler2D tex[3];\n";
- out += "void main() {\n";
- out += "vec4 combiner_buffer = tev_combiner_buffer_color;\n";
- out += "vec4 last_tex_env_out = vec4(0.0);\n";
+void main() {
+)";
// Do not do any sort of processing if it's obvious we're not going to pass the alpha test
if (config.alpha_test_func == Regs::CompareFunc::Never) {
@@ -347,6 +347,10 @@ layout (std140) uniform shader_data {
return out;
}
+ out += "vec4 combiner_buffer = vec4(0.0);\n";
+ out += "vec4 next_combiner_buffer = tev_combiner_buffer_color;\n";
+ out += "vec4 last_tex_env_out = vec4(0.0);\n";
+
for (size_t index = 0; index < config.tev_stages.size(); ++index)
WriteTevStage(out, config, (unsigned)index);