[Mesa-dev] [RFC PATCH 05/56] mesa/main: Add tessellation shader state and limits

[Chris Forbes]

---
 src/mesa/main/config.h    |  8 ++++++++
 src/mesa/main/context.c   | 10 ++++++++++
 src/mesa/main/mtypes.h    |  9 +++++++++
 src/mesa/main/shaderapi.c |  7 +++++++
 4 files changed, 34 insertions(+)

diff --git a/src/mesa/main/config.h b/src/mesa/main/config.h
index 4ec4b75..c0b5914 100644
--- a/src/mesa/main/config.h
+++ b/src/mesa/main/config.h
@@ -300,6 +300,14 @@
 #define MAX_COMPUTE_IMAGE_UNIFORMS          8
 /*@}*/
 
+/** For GL_ARB_tessellation_shader */
+/*@{*/
+#define MAX_TESS_GEN_LEVEL 64
+#define MAX_PATCH_VERTICES 32
+#define MAX_TESS_PATCH_COMPONENTS 120
+#define MAX_TESS_CONTROL_TOTAL_OUTPUT_COMPONENTS 4096
+/*@}*/
+
 /*
  * Color channel component order
  * 
diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index 682b9c7..d9be2f5 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -493,6 +493,8 @@ init_program_limits(struct gl_constants *consts, gl_shader_stage stage,
       prog->MaxInputComponents = 16 * 4; /* old limit not to break tnl and swrast */
       prog->MaxOutputComponents = 0; /* value not used */
       break;
+   case MESA_SHADER_TESS_CTRL:
+   case MESA_SHADER_TESS_EVAL:
    case MESA_SHADER_GEOMETRY:
       prog->MaxParameters = MAX_VERTEX_PROGRAM_PARAMS;
       prog->MaxAttribs = MAX_VERTEX_GENERIC_ATTRIBS;
@@ -723,6 +725,14 @@ _mesa_init_constants(struct gl_constants *consts, gl_api api)
    /** GL_ARB_gpu_shader5 */
    consts->MinFragmentInterpolationOffset = MIN_FRAGMENT_INTERPOLATION_OFFSET;
    consts->MaxFragmentInterpolationOffset = MAX_FRAGMENT_INTERPOLATION_OFFSET;
+
+   /** GL_ARB_tessellation_shader */
+   consts->MaxTessGenLevel = MAX_TESS_GEN_LEVEL;
+   consts->MaxPatchVertices = MAX_PATCH_VERTICES;
+   consts->Program[MESA_SHADER_TESS_CTRL].MaxTextureImageUnits = MAX_TEXTURE_IMAGE_UNITS;
+   consts->Program[MESA_SHADER_TESS_EVAL].MaxTextureImageUnits = MAX_TEXTURE_IMAGE_UNITS;
+   consts->MaxTessPatchComponents = MAX_TESS_PATCH_COMPONENTS;
+   consts->MaxTessControlTotalOutputComponents = MAX_TESS_CONTROL_TOTAL_OUTPUT_COMPONENTS;
 }
 
 
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 23cb98d..9e989d7 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -3486,6 +3486,9 @@ struct gl_program_constants
 
    /* GL_ARB_shader_image_load_store */
    GLuint MaxImageUniforms;
+
+   /* GL_ARB_tessellation_shader */
+   GLuint MaxPatchVertices;
 };
 
 
@@ -3747,6 +3750,12 @@ struct gl_constants
    GLboolean FakeSWMSAA;
 
    struct gl_shader_compiler_options ShaderCompilerOptions[MESA_SHADER_STAGES];
+
+   /** GL_ARB_tessellation_shader */
+   GLuint MaxPatchVertices;
+   GLuint MaxTessGenLevel;
+   GLuint MaxTessPatchComponents;
+   GLuint MaxTessControlTotalOutputComponents;
 };
 
 
diff --git a/src/mesa/main/shaderapi.c b/src/mesa/main/shaderapi.c
index 79d2e94..c11ad4f 100644
--- a/src/mesa/main/shaderapi.c
+++ b/src/mesa/main/shaderapi.c
@@ -105,6 +105,7 @@ _mesa_get_shader_flags(void)
 void
 _mesa_init_shader_state(struct gl_context *ctx)
 {
+   int i;
    /* Device drivers may override these to control what kind of instructions
     * are generated by the GLSL compiler.
     */
@@ -126,6 +127,12 @@ _mesa_init_shader_state(struct gl_context *ctx)
    /* Extended for ARB_separate_shader_objects */
    ctx->Shader.RefCount = 1;
    mtx_init(&ctx->Shader.Mutex, mtx_plain);
+
+   ctx->TessCtrlProgram.patch_vertices = 3;
+   for (i = 0; i < 4; ++i)
+      ctx->TessCtrlProgram.patch_default_outer_level[i] = 1.0;
+   for (i = 0; i < 2; ++i)
+      ctx->TessCtrlProgram.patch_default_inner_level[i] = 1.0;
 }
 
 
-- 
2.1.0