glsl: optionally declare gl_FragCoord & gl_FrontFacing as system values

Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com
Reviewed-by: Brian Paul <brianp@vmware.com>

diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index e6aec3654b89be6f1015706129a7d5f8df8162c2..f3966d7e3f4cd4ae1a9f9112ed69bda740a975e4 100644 (file)
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -3517,7 +3517,7 @@ get_variable_being_redeclared(ir_variable *var, YYLTYPE loc,
               state->is_version(150, 0))
               && strcmp(var->name, "gl_FragCoord") == 0
               && earlier->type == var->type
-              && earlier->data.mode == var->data.mode) {
+              && var->data.mode == ir_var_shader_in) {
       /* Allow redeclaration of gl_FragCoord for ARB_fcc layout
        * qualifiers.
        */

diff --git a/src/glsl/builtin_variables.cpp b/src/glsl/builtin_variables.cpp
index e82c99ee3bbf90690814f00d03cae4f6a98079c4..221aab0043b34ee72756bae74f93628a4a6355c6 100644 (file)
--- a/src/glsl/builtin_variables.cpp
+++ b/src/glsl/builtin_variables.cpp
@@ -1057,8 +1057,16 @@ builtin_variable_generator::generate_fs_special_vars()
 {
    ir_variable *var;
 
-   add_input(VARYING_SLOT_POS, vec4_t, "gl_FragCoord");
-   add_input(VARYING_SLOT_FACE, bool_t, "gl_FrontFacing");
+   if (this->state->ctx->Const.GLSLFragCoordIsSysVal)
+      add_system_value(SYSTEM_VALUE_FRAG_COORD, vec4_t, "gl_FragCoord");
+   else
+      add_input(VARYING_SLOT_POS, vec4_t, "gl_FragCoord");
+
+   if (this->state->ctx->Const.GLSLFrontFacingIsSysVal)
+      add_system_value(SYSTEM_VALUE_FRONT_FACE, bool_t, "gl_FrontFacing");
+   else
+      add_input(VARYING_SLOT_FACE, bool_t, "gl_FrontFacing");
+
    if (state->is_version(120, 100))
       add_input(VARYING_SLOT_PNTC, vec2_t, "gl_PointCoord");
 

diff --git a/src/glsl/nir/shader_enums.h b/src/glsl/nir/shader_enums.h
index 0be217c0cf745ecc44f22de4e0df323d19a22afc..8a2a81a333dcb869a8e59f8778f663b5226fe23c 100644 (file)
--- a/src/glsl/nir/shader_enums.h
+++ b/src/glsl/nir/shader_enums.h
@@ -412,7 +412,8 @@ typedef enum
     * \name Fragment shader system values
     */
    /*@{*/
-   SYSTEM_VALUE_FRONT_FACE,     /**< (not done yet) */
+   SYSTEM_VALUE_FRAG_COORD,
+   SYSTEM_VALUE_FRONT_FACE,
    SYSTEM_VALUE_SAMPLE_ID,
    SYSTEM_VALUE_SAMPLE_POS,
    SYSTEM_VALUE_SAMPLE_MASK_IN,

diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index dd52368ef65a24fb23bccdc93abe2a4e1da25837..41f5283679d8081b1faf5a36dc59c025d050d371 100644 (file)
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -3515,6 +3515,10 @@ struct gl_constants
     */
    GLboolean GLSLSkipStrictMaxUniformLimitCheck;
 
+   /** Whether gl_FragCoord and gl_FrontFacing are system values. */
+   bool GLSLFragCoordIsSysVal;
+   bool GLSLFrontFacingIsSysVal;
+
    /**
     * Always use the GetTransformFeedbackVertexCount() driver hook, rather
     * than passing the transform feedback object to the drawing function.

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index 6cbc26acf79cfec8df781db5a409ed33bf464e22..9308eb4841e12eca8896d890e275d6a6cfce30ad 100644 (file)
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -4459,6 +4459,7 @@ const unsigned _mesa_sysval_to_semantic[SYSTEM_VALUE_MAX] = {
 
    /* Fragment shader
     */
+   TGSI_SEMANTIC_POSITION,
    TGSI_SEMANTIC_FACE,
    TGSI_SEMANTIC_SAMPLEID,
    TGSI_SEMANTIC_SAMPLEPOS,