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 <[email protected]>

1 files changed, 36 insertions, 0 deletions

diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index 83e5de47a88..51b024143ad 100644
--- a/src/mesa/main/context.c
+++ b/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];