From cbef86a6ea7fa2901d2a123544591932114ae603 Mon Sep 17 00:00:00 2001
From: michal <michal@michal-laptop.(none)>
Date: Thu, 16 Aug 2007 12:40:46 +0100
Subject: [PATCH] Copy fragment z if the fragment shader does not write depth
 on its own.`

---
 src/mesa/pipe/tgsi/mesa/mesa_to_tgsi.c | 33 ++++++++++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)

diff --git a/src/mesa/pipe/tgsi/mesa/mesa_to_tgsi.c b/src/mesa/pipe/tgsi/mesa/mesa_to_tgsi.c
index 2ac04e8d56f..2c8deac0346 100644
--- a/src/mesa/pipe/tgsi/mesa/mesa_to_tgsi.c
+++ b/src/mesa/pipe/tgsi/mesa/mesa_to_tgsi.c
@@ -4,7 +4,7 @@
 #define TGSI_DEBUG 1
 
 /*
- * Map mesa register file to SBIR register file.
+ * Map mesa register file to TGSI register file.
  */
 static GLuint
 map_register_file(
@@ -35,7 +35,7 @@ map_register_file(
 }
 
 /**
- * Map mesa register file index to SBIR index.
+ * Map mesa register file index to TGSI index.
  * Take special care when processing input and output indices.
  * \param processor  either TGSI_PROCESSOR_FRAGMENT or  TGSI_PROCESSOR_VERTEX
  * \param file  one of TGSI_FILE_x
@@ -101,7 +101,7 @@ map_register_file_index(
 }
 
 /*
- * Map mesa texture target to SBIR texture target.
+ * Map mesa texture target to TGSI texture target.
  */
 static GLuint
 map_texture_target(
@@ -609,6 +609,33 @@ tgsi_mesa_compile_fp_program(
          maxTokens - ti );
    }
 
+   /*
+    * Copy fragment z if the shader does not write it.
+    */
+   if( !(program->Base.OutputsWritten & (1 << FRAG_RESULT_DEPR)) ) {
+      fullinst = tgsi_default_full_instruction();
+
+      fullinst.Instruction.Opcode = TGSI_OPCODE_MOV;
+      fullinst.Instruction.NumDstRegs = 1;
+      fullinst.Instruction.NumSrcRegs = 1;
+
+      fulldst = &fullinst.FullDstRegisters[0];
+      fulldst->DstRegister.File = TGSI_FILE_OUTPUT;
+      fulldst->DstRegister.Index = 0;
+      fulldst->DstRegister.WriteMask = TGSI_WRITEMASK_Z;
+
+      fullsrc = &fullinst.FullSrcRegisters[0];
+      fullsrc->SrcRegister.File = TGSI_FILE_INPUT;
+      fullsrc->SrcRegister.Index = 0;
+
+      ti += tgsi_build_full_instruction(
+         &fullinst,
+         &tokens[ti],
+         header,
+         maxTokens - ti );
+      preamble_size++;
+   }
+
    for( i = 0; i < program->Base.NumInstructions; i++ ) {
       if( compile_instruction(
             &program->Base.Instructions[i],
-- 
2.11.0