mesa/main: Add support for GL_ARB_cull_distance (v2)

airlied:
v2: rename LowerClipDistance to LowerCombinedClipCullDistnace.
I don't think we want any other behaviour with any current hw.

Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

src/compiler/glsl/link_varyings.cpp

@@ -627,7 +627,7 @@ tfeedback_decl::init(struct gl_context *ctx, const void *mem_ctx,
     * class must behave specially to account for the fact that gl_ClipDistance
     * is converted from a float[8] to a vec4[2].
     */
-   if (ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerClipDistance &&
+   if (ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerCombinedClipCullDistance &&
        strcmp(this->var_name, "gl_ClipDistance") == 0) {
       this->lowered_builtin_array_variable = clip_distance;
    }

src/compiler/glsl/linker.cpp

@@ -4560,7 +4560,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       if (!prog->LinkStatus)
 	 goto done;
 
-      if (ctx->Const.ShaderCompilerOptions[i].LowerClipDistance) {
+      if (ctx->Const.ShaderCompilerOptions[i].LowerCombinedClipCullDistance) {
          lower_clip_distance(prog->_LinkedShaders[i]);
       }
 

src/compiler/glsl/lower_clip_distance.cpp

@@ -42,7 +42,7 @@
  *
  * Since some hardware may not internally represent gl_ClipDistance as a pair
  * of vec4's, this lowering pass is optional.  To enable it, set the
- * LowerClipDistance flag in gl_shader_compiler_options to true.
+ * LowerCombinedClipCullDistance flag in gl_shader_compiler_options to true.
  */
 
 #include "glsl_symbol_table.h"

src/mesa/drivers/dri/i965/brw_compiler.c

@@ -168,7 +168,7 @@ brw_compiler_create(void *mem_ctx, const struct brw_device_info *devinfo)
       compiler->glsl_compiler_options[i].EmitNoMainReturn = true;
       compiler->glsl_compiler_options[i].EmitNoIndirectInput = true;
       compiler->glsl_compiler_options[i].EmitNoIndirectUniform = false;
-      compiler->glsl_compiler_options[i].LowerClipDistance = true;
+      compiler->glsl_compiler_options[i].LowerCombinedClipCullDistance = true;
 
       bool is_scalar = compiler->scalar_stage[i];
 

src/mesa/main/extensions_table.h

@@ -44,6 +44,7 @@ EXT(ARB_conditional_render_inverted         , ARB_conditional_render_inverted
 EXT(ARB_conservative_depth                  , ARB_conservative_depth                 , GLL, GLC,  x ,  x , 2011)
 EXT(ARB_copy_buffer                         , dummy_true                             , GLL, GLC,  x ,  x , 2008)
 EXT(ARB_copy_image                          , ARB_copy_image                         , GLL, GLC,  x ,  x , 2012)
+EXT(ARB_cull_distance                       , ARB_cull_distance                      , GLL, GLC,  x ,  x , 2014)
 EXT(ARB_debug_output                        , dummy_true                             , GLL, GLC,  x ,  x , 2009)
 EXT(ARB_depth_buffer_float                  , ARB_depth_buffer_float                 , GLL, GLC,  x ,  x , 2008)
 EXT(ARB_depth_clamp                         , ARB_depth_clamp                        , GLL, GLC,  x ,  x , 2003)

src/mesa/main/get.c

@@ -465,6 +465,7 @@ EXTRA_EXT(ARB_shader_storage_buffer_object);
 EXTRA_EXT(ARB_indirect_parameters);
 EXTRA_EXT(ATI_meminfo);
 EXTRA_EXT(NVX_gpu_memory_info);
+EXTRA_EXT(ARB_cull_distance);
 
 static const int
 extra_ARB_color_buffer_float_or_glcore[] = {

src/mesa/main/get_hash_params.py

@@ -878,6 +878,10 @@ descriptor=[
   [ "GPU_MEMORY_INFO_CURRENT_AVAILABLE_VIDMEM_NVX", "LOC_CUSTOM, TYPE_INT, NO_OFFSET, extra_NVX_gpu_memory_info" ],
   [ "GPU_MEMORY_INFO_EVICTION_COUNT_NVX", "LOC_CUSTOM, TYPE_INT, NO_OFFSET, extra_NVX_gpu_memory_info" ],
   [ "GPU_MEMORY_INFO_EVICTED_MEMORY_NVX", "LOC_CUSTOM, TYPE_INT, NO_OFFSET, extra_NVX_gpu_memory_info" ],
+
+# GL_ARB_cull_distance
+  [ "MAX_CULL_DISTANCES", "CONTEXT_INT(Const.MaxClipPlanes), extra_ARB_cull_distance" ],
+  [ "MAX_COMBINED_CLIP_AND_CULL_DISTANCES", "CONTEXT_INT(Const.MaxClipPlanes), extra_ARB_cull_distance" ],
 ]},
 
 # Enums restricted to OpenGL Core profile

src/mesa/main/mtypes.h

@@ -1922,6 +1922,7 @@ struct gl_program
     * gl_ClipDistance output.  Ignored for fragment shaders.
     */
    unsigned ClipDistanceArraySize;
+   unsigned CullDistanceArraySize;
 
 
    /** Named parameters, constants, etc. from program text */
@@ -2703,6 +2704,8 @@ struct gl_shader_program
        */
       GLuint ClipDistanceArraySize; /**< Size of the gl_ClipDistance array, or
                                          0 if not present. */
+      GLuint CullDistanceArraySize; /**< Size of the gl_CullDistance array, or
+                                         0 if not present. */
    } TessEval;
 
    /**
@@ -2725,6 +2728,8 @@ struct gl_shader_program
        */
       GLuint ClipDistanceArraySize; /**< Size of the gl_ClipDistance array, or
                                          0 if not present. */
+      GLuint CullDistanceArraySize; /**< Size of the gl_CullDistance array, or
+                                         0 if not present. */
       bool UsesEndPrimitive;
       bool UsesStreams;
    } Geom;
@@ -2737,6 +2742,8 @@ struct gl_shader_program
        */
       GLuint ClipDistanceArraySize; /**< Size of the gl_ClipDistance array, or
                                          0 if not present. */
+      GLuint CullDistanceArraySize; /**< Size of the gl_CullDistance array, or
+                                         0 if not present. */
    } Vert;
 
    /**
@@ -2780,6 +2787,7 @@ struct gl_shader_program
     * stage before the fragment shader.
     */
    unsigned LastClipDistanceArraySize;
+   unsigned LastCullDistanceArraySize;
 
    unsigned NumUniformBlocks;
    struct gl_uniform_block *UniformBlocks;
@@ -2911,7 +2919,10 @@ struct gl_shader_compiler_options
    GLboolean EmitNoNoise;                 /**< Emit NOISE opcodes? */
    GLboolean EmitNoPow;                   /**< Emit POW opcodes? */
    GLboolean EmitNoSat;                   /**< Emit SAT opcodes? */
-   GLboolean LowerClipDistance; /**< Lower gl_ClipDistance from float[8] to vec4[2]? */
+   GLboolean LowerCombinedClipCullDistance; /** Lower gl_ClipDistance and
+                                              * gl_CullDistance together from
+                                              * float[8] to vec4[2]
+                                              **/
 
    /**
     * \name Forms of indirect addressing the driver cannot do.
@@ -3742,6 +3753,7 @@ struct gl_extensions
    GLboolean ARB_conditional_render_inverted;
    GLboolean ARB_conservative_depth;
    GLboolean ARB_copy_image;
+   GLboolean ARB_cull_distance;
    GLboolean ARB_depth_buffer_float;
    GLboolean ARB_depth_clamp;
    GLboolean ARB_depth_texture;

src/mesa/main/shaderapi.c

@@ -2080,6 +2080,7 @@ _mesa_copy_linked_program_data(gl_shader_stage type,
    switch (type) {
    case MESA_SHADER_VERTEX:
       dst->ClipDistanceArraySize = src->Vert.ClipDistanceArraySize;
+      dst->CullDistanceArraySize = src->Vert.CullDistanceArraySize;
       break;
    case MESA_SHADER_TESS_CTRL: {
       struct gl_tess_ctrl_program *dst_tcp =
@@ -2095,6 +2096,7 @@ _mesa_copy_linked_program_data(gl_shader_stage type,
       dst_tep->VertexOrder = src->TessEval.VertexOrder;
       dst_tep->PointMode = src->TessEval.PointMode;
       dst->ClipDistanceArraySize = src->TessEval.ClipDistanceArraySize;
+      dst->CullDistanceArraySize = src->TessEval.CullDistanceArraySize;
       break;
    }
    case MESA_SHADER_GEOMETRY: {
@@ -2105,6 +2107,7 @@ _mesa_copy_linked_program_data(gl_shader_stage type,
       dst_gp->InputType = src->Geom.InputType;
       dst_gp->OutputType = src->Geom.OutputType;
       dst->ClipDistanceArraySize = src->Geom.ClipDistanceArraySize;
+      dst->CullDistanceArraySize = src->Geom.CullDistanceArraySize;
       dst_gp->UsesEndPrimitive = src->Geom.UsesEndPrimitive;
       dst_gp->UsesStreams = src->Geom.UsesStreams;
       break;

src/mesa/state_tracker/st_extensions.c

@@ -306,7 +306,7 @@ void st_init_limits(struct pipe_screen *screen,
             screen->get_shader_param(screen, sh,
                                   PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT);
 
-      options->LowerClipDistance = true;
+      options->LowerCombinedClipCullDistance = true;
       options->LowerBufferInterfaceBlocks = true;
 
       if (sh == PIPE_SHADER_COMPUTE)