gl_FragCoord support.

src/xenia/gpu/gl4/draw_batcher.cc

@@ -195,6 +195,7 @@ bool DrawBatcher::BeginDraw() {
   auto state_host_ptr =
       reinterpret_cast<uintptr_t>(active_draw_.state_allocation.host_ptr);
   active_draw_.header = reinterpret_cast<CommonHeader*>(state_host_ptr);
+  active_draw_.header->ps_param_gen = -1;
   // active_draw_.float_consts =
   //    reinterpret_cast<float4*>(state_host_ptr +
   //    batch_state_.float_consts_offset);

src/xenia/gpu/gl4/draw_batcher.h

@@ -75,6 +75,9 @@ class DrawBatcher {
     active_draw_.header->alpha_test.y = static_cast<float>(func);
     active_draw_.header->alpha_test.z = ref;
   }
+  void set_ps_param_gen(int register_index) {
+    active_draw_.header->ps_param_gen = register_index;
+  }
   void set_texture_sampler(int index, GLuint64 handle) {
     active_draw_.header->texture_samplers[index] = handle;
   }
@@ -132,6 +135,8 @@ class DrawBatcher {
     float4 window_scale;  // sx,sy, ?, ?
     float4 vtx_fmt;       //
     float4 alpha_test;    // alpha test enable, func, ref, ?
+    int ps_param_gen;
+    int padding[3];
 
     // TODO(benvanik): pack tightly
     GLuint64 texture_samplers[32];

src/xenia/gpu/gl4/gl4_command_processor.cc

@@ -623,6 +623,7 @@ GL4CommandProcessor::UpdateStatus GL4CommandProcessor::UpdateShaders(
   dirty |= SetShadowRegister(&regs.pa_su_sc_mode_cntl,
                              XE_GPU_REG_PA_SU_SC_MODE_CNTL);
   dirty |= SetShadowRegister(&regs.sq_program_cntl, XE_GPU_REG_SQ_PROGRAM_CNTL);
+  dirty |= SetShadowRegister(&regs.sq_context_misc, XE_GPU_REG_SQ_CONTEXT_MISC);
   dirty |= regs.vertex_shader != active_vertex_shader_;
   dirty |= regs.pixel_shader != active_pixel_shader_;
   dirty |= regs.prim_type != prim_type;
@@ -640,6 +641,10 @@ GL4CommandProcessor::UpdateStatus GL4CommandProcessor::UpdateShaders(
   xe_gpu_program_cntl_t program_cntl;
   program_cntl.dword_0 = regs.sq_program_cntl;
 
+  // Populate a register in the pixel shader with frag coord.
+  int ps_param_gen = (regs.sq_context_misc >> 8) & 0xFF;
+  draw_batcher_.set_ps_param_gen(program_cntl.param_gen ? ps_param_gen : -1);
+
   // Normal vertex shaders only, for now.
   // TODO(benvanik): transform feedback/memexport.
   // 0 = normal

src/xenia/gpu/gl4/gl4_command_processor.h

@@ -213,6 +213,7 @@ class GL4CommandProcessor : public CommandProcessor {
     PrimitiveType prim_type;
     uint32_t pa_su_sc_mode_cntl;
     uint32_t sq_program_cntl;
+    uint32_t sq_context_misc;
     GL4Shader* vertex_shader;
     GL4Shader* pixel_shader;