mesa: add support for ARB_blend_func_extended (v4)

Add implementations of the two API functions,
Add a new strings to uint mapping for index bindings
Add the blending mode validation for SRC1 + SRC_ALPHA_SATURATE
Add get for MAX_DUAL_SOURCE_DRAW_BUFFERS

v2:
Add check in valid_to_render to address case in spec ERRORS.

v3:
Add index to ir.h so this patch compiles on its own
fixup comment

v4: fixup Brian's comments

The GLSL patch will setup the indices.

Signed-off-by: Dave Airlie <airlied@redhat.com>

src/glsl/ir.h

@@ -420,6 +420,11 @@ public:
     */
    int location;
 
+   /**
+    * output index for dual source blending.
+    */
+   int index;
+
    /**
     * Built-in state that backs this uniform
     *

src/mesa/main/blend.c

@@ -63,6 +63,11 @@ legal_src_factor(const struct gl_context *ctx, GLenum factor)
    case GL_CONSTANT_ALPHA:
    case GL_ONE_MINUS_CONSTANT_ALPHA:
       return GL_TRUE;
+   case GL_SRC1_COLOR:
+   case GL_SRC1_ALPHA:
+   case GL_ONE_MINUS_SRC1_COLOR:
+   case GL_ONE_MINUS_SRC1_ALPHA:
+      return ctx->Extensions.ARB_blend_func_extended;
    default:
       return GL_FALSE;
    }
@@ -93,6 +98,12 @@ legal_dst_factor(const struct gl_context *ctx, GLenum factor)
    case GL_CONSTANT_ALPHA:
    case GL_ONE_MINUS_CONSTANT_ALPHA:
       return GL_TRUE;
+   case GL_SRC_ALPHA_SATURATE:
+   case GL_SRC1_COLOR:
+   case GL_SRC1_ALPHA:
+   case GL_ONE_MINUS_SRC1_COLOR:
+   case GL_ONE_MINUS_SRC1_ALPHA:
+      return ctx->Extensions.ARB_blend_func_extended;
    default:
       return GL_FALSE;
    }

src/mesa/main/context.c

@@ -1695,7 +1695,39 @@ _mesa_set_mvp_with_dp4( struct gl_context *ctx,
    ctx->mvp_with_dp4 = flag;
 }
 
+static GLboolean
+blend_factor_is_dual_src(GLenum factor)
+{
+   return factor == GL_SRC1_COLOR || factor == GL_SRC1_ALPHA ||
+      factor == GL_ONE_MINUS_SRC1_COLOR || factor == GL_ONE_MINUS_SRC1_ALPHA;
+}
 
+/*
+ * ARB_blend_func_extended - ERRORS section
+ * "The error INVALID_OPERATION is generated by Begin or any procedure that
+ *  implicitly calls Begin if any draw buffer has a blend function requiring the
+ *  second color input (SRC1_COLOR, ONE_MINUS_SRC1_COLOR, SRC1_ALPHA or
+ *  ONE_MINUS_SRC1_ALPHA), and a framebuffer is bound that has more than
+ *  the value of MAX_DUAL_SOURCE_DRAW_BUFFERS-1 active color attachements."
+ */
+static GLboolean
+_mesa_check_blend_func_error(struct gl_context *ctx)
+{
+   GLuint i;
+   for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) {
+      if (blend_factor_is_dual_src(ctx->Color.Blend[i].SrcRGB) ||
+          blend_factor_is_dual_src(ctx->Color.Blend[i].DstRGB) ||
+          blend_factor_is_dual_src(ctx->Color.Blend[i].SrcA) ||
+          blend_factor_is_dual_src(ctx->Color.Blend[i].DstA)) {
+         if (i >= ctx->Const.MaxDualSourceDrawBuffers) {
+            _mesa_error(ctx, GL_INVALID_OPERATION,
+                        "dual source blend on illegal attachment");
+            return GL_FALSE;
+         }
+      }
+   }
+   return GL_TRUE;
+}
 
 /**
  * Prior to drawing anything with glBegin, glDrawArrays, etc. this function
@@ -1816,6 +1848,10 @@ _mesa_valid_to_render(struct gl_context *ctx, const char *where)
       return GL_FALSE;
    }
 
+   if (_mesa_check_blend_func_error(ctx) == GL_FALSE) {
+      return GL_FALSE;
+   }
+
 #ifdef DEBUG
    if (ctx->Shader.Flags & GLSL_LOG) {
       struct gl_shader_program *shProg[MESA_SHADER_TYPES];

src/mesa/main/get.c

@@ -333,6 +333,7 @@ EXTRA_EXT(ARB_copy_buffer);
 EXTRA_EXT(EXT_framebuffer_sRGB);
 EXTRA_EXT(ARB_texture_buffer_object);
 EXTRA_EXT(OES_EGL_image_external);
+EXTRA_EXT(ARB_blend_func_extended);
 
 static const int
 extra_ARB_vertex_program_ARB_fragment_program_NV_vertex_program[] = {
@@ -1304,6 +1305,8 @@ static const struct value_desc values[] = {
    { GL_MAX_DEBUG_LOGGED_MESSAGES_ARB, CONST(MAX_DEBUG_LOGGED_MESSAGES), NO_EXTRA },
    { GL_MAX_DEBUG_MESSAGE_LENGTH_ARB, CONST(MAX_DEBUG_MESSAGE_LENGTH), NO_EXTRA },
 
+   { GL_MAX_DUAL_SOURCE_DRAW_BUFFERS, CONTEXT_INT(Const.MaxDualSourceDrawBuffers), extra_ARB_blend_func_extended },
+
 #endif /* FEATURE_GL */
 };
 

src/mesa/main/mtypes.h

@@ -2263,6 +2263,7 @@ struct gl_shader_program
     * and they are \b not the values returned by \c glGetFragDataLocation.
     */
    struct string_to_uint_map *FragDataBindings;
+   struct string_to_uint_map *FragDataIndexBindings;
 
    /**
     * Transform feedback varyings last specified by
@@ -2814,6 +2815,9 @@ struct gl_constants
    /* GL_ARB_robustness */
    GLenum ResetStrategy;
 
+   /* GL_ARB_blend_func_extended */
+   GLuint MaxDualSourceDrawBuffers;
+
    /**
     * Whether the implementation strips out and ignores texture borders.
     *

src/mesa/main/shader_query.cpp

@@ -238,11 +238,18 @@ _mesa_longest_attribute_name_length(struct gl_shader_program *shProg)
 void GLAPIENTRY
 _mesa_BindFragDataLocation(GLuint program, GLuint colorNumber,
 			   const GLchar *name)
+{
+   _mesa_BindFragDataLocationIndexed(program, colorNumber, 0, name);
+}
+
+void GLAPIENTRY
+_mesa_BindFragDataLocationIndexed(GLuint program, GLuint colorNumber,
+                                  GLuint index, const GLchar *name)
 {
    GET_CURRENT_CONTEXT(ctx);
 
    struct gl_shader_program *const shProg =
-      _mesa_lookup_shader_program_err(ctx, program, "glBindFragDataLocation");
+      _mesa_lookup_shader_program_err(ctx, program, "glBindFragDataLocationIndexed");
    if (!shProg)
       return;
 
@@ -250,13 +257,22 @@ _mesa_BindFragDataLocation(GLuint program, GLuint colorNumber,
       return;
 
    if (strncmp(name, "gl_", 3) == 0) {
-      _mesa_error(ctx, GL_INVALID_OPERATION,
+      _mesa_error(ctx, GL_INVALID_OPERATION, "glBindFragDataLocationIndexed(illegal name)");
-                  "glBindFragDataLocation(illegal name)");
       return;
    }
 
-   if (colorNumber >= ctx->Const.MaxDrawBuffers) {
+   if (index > 1) {
-      _mesa_error(ctx, GL_INVALID_VALUE, "glBindFragDataLocation(index)");
+      _mesa_error(ctx, GL_INVALID_VALUE, "glBindFragDataLocationIndexed(index)");
+      return;
+   }
+
+   if (index == 0 && colorNumber >= ctx->Const.MaxDrawBuffers) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glBindFragDataLocationIndexed(colorNumber)");
+      return;
+   }
+
+   if (index == 1 && colorNumber >= ctx->Const.MaxDualSourceDrawBuffers) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glBindFragDataLocationIndexed(colorNumber)");
       return;
    }
 
@@ -265,11 +281,68 @@ _mesa_BindFragDataLocation(GLuint program, GLuint colorNumber,
     * between built-in attributes and user-defined attributes.
     */
    shProg->FragDataBindings->put(colorNumber + FRAG_RESULT_DATA0, name);
-
+   shProg->FragDataIndexBindings->put(index, name);
    /*
     * Note that this binding won't go into effect until
     * glLinkProgram is called again.
     */
+
+}
+
+GLint GLAPIENTRY
+_mesa_GetFragDataIndex(GLuint program, const GLchar *name)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   struct gl_shader_program *const shProg =
+      _mesa_lookup_shader_program_err(ctx, program, "glGetFragDataIndex");
+
+   if (!shProg) {
+      return -1;
+   }
+
+   if (!shProg->LinkStatus) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glGetFragDataIndex(program not linked)");
+      return -1;
+   }
+
+   if (!name)
+      return -1;
+
+   if (strncmp(name, "gl_", 3) == 0) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glGetFragDataIndex(illegal name)");
+      return -1;
+   }
+
+   /* Not having a fragment shader is not an error.
+    */
+   if (shProg->_LinkedShaders[MESA_SHADER_FRAGMENT] == NULL)
+      return -1;
+
+   exec_list *ir = shProg->_LinkedShaders[MESA_SHADER_FRAGMENT]->ir;
+   foreach_list(node, ir) {
+      const ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+      /* The extra check against FRAG_RESULT_DATA0 is because
+       * glGetFragDataLocation cannot be used on "conventional" attributes.
+       *
+       * From page 95 of the OpenGL 3.0 spec:
+       *
+       *     "If name is not an active attribute, if name is a conventional
+       *     attribute, or if an error occurs, -1 will be returned."
+       */
+      if (var == NULL
+          || var->mode != ir_var_out
+          || var->location == -1
+          || var->location < FRAG_RESULT_DATA0)
+         continue;
+
+      if (strcmp(var->name, name) == 0)
+         return var->index;
+   }
+
+   return -1;
 }
 
 GLint GLAPIENTRY

src/mesa/main/shaderapi.c

@@ -1748,6 +1748,9 @@ _mesa_init_shader_dispatch(struct _glapi_table *exec)
    SET_ReleaseShaderCompiler(exec, _mesa_ReleaseShaderCompiler);
    SET_GetShaderPrecisionFormat(exec, _mesa_GetShaderPrecisionFormat);
 
+   /* GL_ARB_blend_func_extended */
+   SET_BindFragDataLocationIndexed(exec, _mesa_BindFragDataLocationIndexed);
+   SET_GetFragDataIndex(exec, _mesa_GetFragDataIndex);
 #endif /* FEATURE_GL */
 }
 

src/mesa/main/shaderapi.h

@@ -86,6 +86,9 @@ _mesa_GetAttachedObjectsARB(GLhandleARB, GLsizei, GLsizei *, GLhandleARB *);
 extern GLint GLAPIENTRY
 _mesa_GetFragDataLocation(GLuint program, const GLchar *name);
 
+extern GLint GLAPIENTRY
+_mesa_GetFragDataIndex(GLuint program, const GLchar *name);
+
 extern GLhandleARB GLAPIENTRY
 _mesa_GetHandleARB(GLenum pname);
 
@@ -127,6 +130,10 @@ extern void GLAPIENTRY
 _mesa_BindFragDataLocation(GLuint program, GLuint colorNumber,
                            const GLchar *name);
 
+extern void GLAPIENTRY
+_mesa_BindFragDataLocationIndexed(GLuint program, GLuint colorNumber,
+                                  GLuint index, const GLchar *name);
+
 extern void GLAPIENTRY
 _mesa_GetActiveAttribARB(GLhandleARB, GLuint, GLsizei, GLsizei *, GLint *,
                          GLenum *, GLcharARB *);

src/mesa/main/shaderobj.c

@@ -242,6 +242,7 @@ _mesa_init_shader_program(struct gl_context *ctx, struct gl_shader_program *prog
 
    prog->AttributeBindings = string_to_uint_map_ctor();
    prog->FragDataBindings = string_to_uint_map_ctor();
+   prog->FragDataIndexBindings = string_to_uint_map_ctor();
 
 #if FEATURE_ARB_geometry_shader4
    prog->Geom.VerticesOut = 0;
@@ -319,6 +320,11 @@ _mesa_free_shader_program_data(struct gl_context *ctx,
       shProg->FragDataBindings = NULL;
    }
 
+   if (shProg->FragDataIndexBindings) {
+      string_to_uint_map_dtor(shProg->FragDataIndexBindings);
+      shProg->FragDataIndexBindings = NULL;
+   }
+
    /* detach shaders */
    for (i = 0; i < shProg->NumShaders; i++) {
       _mesa_reference_shader(ctx, &shProg->Shaders[i], NULL);