Shader tev combiner buffer color initialization

src/video_core/renderer_opengl/gl_rasterizer.cpp

@@ -57,6 +57,8 @@ void RasterizerOpenGL::InitObjects() {
 
     uniform_tex = glGetUniformLocation(shader.GetHandle(), "tex");
 
+    uniform_tev_combiner_buffer_color = glGetUniformLocation(shader.GetHandle(), "tev_combiner_buffer_color");
+
     for (int i = 0; i < 6; ++i) {
         auto& uniform_tev = uniform_tev_cfgs[i];
 
@@ -491,6 +493,14 @@ void RasterizerOpenGL::SyncDrawState() {
         }
     }
 
+    // Sync intial combiner buffer color
+    GLfloat initial_combiner_color[4] = { Pica::registers.tev_combiner_buffer_color.r / 255.0f,
+                                          Pica::registers.tev_combiner_buffer_color.g / 255.0f,
+                                          Pica::registers.tev_combiner_buffer_color.b / 255.0f,
+                                          Pica::registers.tev_combiner_buffer_color.a / 255.0f };
+
+    glUniform4fv(uniform_tev_combiner_buffer_color, 1, initial_combiner_color);
+
     // Sync texture environment configurations to hw shader
     const auto tev_stages = Pica::registers.GetTevStages();
     for (unsigned tev_stage_idx = 0; tev_stage_idx < tev_stages.size(); ++tev_stage_idx) {

src/video_core/renderer_opengl/gl_rasterizer.h

@@ -146,6 +146,7 @@ private:
     GLuint uniform_alphatest_func;
     GLuint uniform_alphatest_ref;
     GLuint uniform_tex;
+    GLuint uniform_tev_combiner_buffer_color;
     TEVConfigUniforms uniform_tev_cfgs[6];
     GLuint uniform_out_maps;
     GLuint uniform_tex_envs;

src/video_core/renderer_opengl/gl_shaders.h

@@ -140,6 +140,8 @@ uniform float alphatest_ref;
 
 uniform sampler2D tex[3];
 
+uniform vec4 tev_combiner_buffer_color;
+
 struct TEVConfig
 {
     ivec3 color_sources;
@@ -309,6 +311,8 @@ void ProcessTexEnv(int tex_env_idx) {
 }
 
 void main(void) {
+    g_combiner_buffer = tev_combiner_buffer_color;
+
     for (int i = 0; i < NUM_TEV_STAGES; ++i) {
         ProcessTexEnv(i);
     }