comments

diff --git a/src/mesa/pipe/tgsi/mesa/mesa_to_tgsi.c b/src/mesa/pipe/tgsi/mesa/mesa_to_tgsi.c
index 291e62d262f2081e43609cbec38596021c030652..dc25bac4ea5381d7aa8bd73dfe5c3a6c8b610d74 100644 (file)
--- a/src/mesa/pipe/tgsi/mesa/mesa_to_tgsi.c
+++ b/src/mesa/pipe/tgsi/mesa/mesa_to_tgsi.c
@@ -31,22 +31,34 @@ map_register_file(
    }\r
 }\r
 \r
-/*\r
+/**\r
  * Map mesa register file index to SBIR index.\r
  * Take special care when processing input and output indices.\r
+ * \param processor  either TGSI_PROCESSOR_FRAGMENT or  TGSI_PROCESSOR_VERTEX\r
+ * \param file  one of TGSI_FILE_x\r
+ * \param index  the mesa register file index\r
+ * \param usage_bitmask  ???\r
  */\r
 static GLuint\r
 map_register_file_index(\r
    GLuint processor,\r
    GLuint file,\r
    GLuint index,\r
-   GLuint usage_bitmask )\r
+   GLbitfield usage_bitmask )\r
 {\r
    GLuint mapped_index;\r
    GLuint i;\r
 \r
    switch( file ) {\r
    case TGSI_FILE_INPUT:\r
+      /*\r
+       * The fragment/vertex program input indexes (FRAG/VERT_ATTRIB_x) get\r
+       * mapped to a packed sequence of integers.\r
+       * If a program uses one input attribute, the mapped index will be 1.\r
+       * If a program uses two input attribs, the mapped indexes will be 1,2.\r
+       * If a program uses 3 input attribs, the mapped indexes will be 1,2,3.\r
+       * etc.\r
+       */\r
       assert( index < 32 );\r
       assert( usage_bitmask & (1 << index) );\r
       mapped_index = 0;\r
@@ -55,11 +67,15 @@ map_register_file_index(
             mapped_index++;\r
          }\r
       }\r
+      printf("Map input %d to %d\n", index, mapped_index);\r
       break;\r
 \r
    case TGSI_FILE_OUTPUT:\r
-      assert( usage_bitmask == 0 );\r
+      assert( usage_bitmask == 0x0 );\r
       if( processor == TGSI_PROCESSOR_FRAGMENT ) {\r
+         /* depth result  -> index 0\r
+          * color results -> index 1, 2, ...\r
+          */\r
         if( index == FRAG_RESULT_DEPR ) {\r
             mapped_index = 0;\r
          }\r
@@ -69,6 +85,7 @@ map_register_file_index(
          }\r
       }\r
       else {\r
+         /* mapped_index = VERT_RESULT_x */\r
          mapped_index = index;\r
       }\r
       break;\r
@@ -137,7 +154,7 @@ convert_writemask(
 \r
 static GLboolean\r
 compile_instruction(\r
-   struct prog_instruction *inst,\r
+   const struct prog_instruction *inst,\r
    struct tgsi_full_instruction *fullinst,\r
    GLuint inputs_read,\r
    GLuint processor )\r
@@ -158,7 +175,7 @@ compile_instruction(
       processor,\r
       fulldst->DstRegister.File,\r
       inst->DstReg.Index,\r
-      0 );\r
+      0x0 );\r
    fulldst->DstRegister.WriteMask = convert_writemask( inst->DstReg.WriteMask );\r
 \r
    for( i = 0; i < fullinst->Instruction.NumSrcRegs; i++ ) {\r