Pica: Use zero for the SecondaryFragmentColor source.

- This is a workaround until we support fragment lighting.

src/video_core/pica.h

@@ -240,6 +240,7 @@ struct Regs {
         enum class Source : u32 {
             PrimaryColor           = 0x0,
             PrimaryFragmentColor   = 0x1,
+            SecondaryFragmentColor = 0x2,
 
             Texture0               = 0x3,
             Texture1               = 0x4,

src/video_core/rasterizer.cpp

@@ -402,11 +402,16 @@ static void ProcessTriangleInternal(const VertexShader::OutputVertex& v0,
 
                 auto GetSource = [&](Source source) -> Math::Vec4<u8> {
                     switch (source) {
-                    // TODO: What's the difference between these two?
                     case Source::PrimaryColor:
+
+                    // HACK: Until we implement fragment lighting, use primary_color
                     case Source::PrimaryFragmentColor:
                         return primary_color;
 
+                    // HACK: Until we implement fragment lighting, use zero
+                    case Source::SecondaryFragmentColor:
+                        return {0, 0, 0, 0};
+
                     case Source::Texture0:
                         return texture_color[0];
 

src/video_core/renderer_opengl/gl_shaders.h

@@ -71,6 +71,7 @@ const char g_fragment_shader_hw[] = R"(
 
 #define SOURCE_PRIMARYCOLOR           0x0
 #define SOURCE_PRIMARYFRAGMENTCOLOR   0x1
+#define SOURCE_SECONDARYFRAGMENTCOLOR 0x2
 #define SOURCE_TEXTURE0               0x3
 #define SOURCE_TEXTURE1               0x4
 #define SOURCE_TEXTURE2               0x5
@@ -151,8 +152,11 @@ vec4 GetSource(int source) {
     if (source == SOURCE_PRIMARYCOLOR) {
         return o[2];
     } else if (source == SOURCE_PRIMARYFRAGMENTCOLOR) {
-        // HACK: Uses color value, but should really use fragment lighting output
+        // HACK: Until we implement fragment lighting, use primary_color
         return o[2];
+    } else if (source == SOURCE_SECONDARYFRAGMENTCOLOR) {
+        // HACK: Until we implement fragment lighting, use zero
+        return vec4(0.0, 0.0, 0.0, 0.0);
     } else if (source == SOURCE_TEXTURE0) {
         return texture(tex[0], o[3].xy);
     } else if (source == SOURCE_TEXTURE1) {