mesa: implement DrawTransformFeedback from ARB_transform_feedback2

It's like DrawArrays, but the count is taken from a transform feedback
object.

This removes DrawTransformFeedback from dd_function_table and adds the same
function to GLvertexformat (with the function parameters matching GL).

The vbo_draw_func callback has a new parameter
"struct gl_transform_feedback_object *tfb_vertcount".

The rest of the code just validates states and forwards the transform
feedback object into vbo_draw_func.

5 files changed, 11 insertions, 18 deletions

diff --git a/src/mesa/state_tracker/st_cb_rasterpos.c b/src/mesa/state_tracker/st_cb_rasterpos.c
index 32d465c5cce..2c21dc9a776 100644
--- a/src/mesa/state_tracker/st_cb_rasterpos.c
+++ b/src/mesa/state_tracker/st_cb_rasterpos.c
@@ -251,7 +251,8 @@ st_RasterPos(struct gl_context *ctx, const GLfloat v[4])
    rs->array[0].Ptr = (GLubyte *) v;
 
    /* draw the point */
-   st_feedback_draw_vbo(ctx, rs->arrays, &rs->prim, 1, NULL, GL_TRUE, 0, 1);
+   st_feedback_draw_vbo(ctx, rs->arrays, &rs->prim, 1, NULL, GL_TRUE, 0, 1,
+                        NULL);
 
    /* restore draw's rasterization stage depending on rendermode */
    if (ctx->RenderMode == GL_FEEDBACK) {
diff --git a/src/mesa/state_tracker/st_cb_xformfb.c b/src/mesa/state_tracker/st_cb_xformfb.c
index e415b186aa7..a17b54d326e 100644
--- a/src/mesa/state_tracker/st_cb_xformfb.c
+++ b/src/mesa/state_tracker/st_cb_xformfb.c
@@ -105,18 +105,6 @@ st_resume_transform_feedback(struct gl_context *ctx,
 }
 
 
-static void
-st_draw_transform_feedback(struct gl_context *ctx, GLenum mode,
-                           struct gl_transform_feedback_object *obj)
-{
-   /* XXX to do */
-   /*
-    * Get number of vertices in obj's feedback buffer.
-    * Call ctx->Exec.DrawArrays(mode, 0, count);
-    */
-}
-
-
 void
 st_init_xformfb_functions(struct dd_function_table *functions)
 {
@@ -128,7 +116,6 @@ st_init_xformfb_functions(struct dd_function_table *functions)
    functions->EndTransformFeedback = st_end_transform_feedback;
    functions->PauseTransformFeedback = st_pause_transform_feedback;
    functions->ResumeTransformFeedback = st_resume_transform_feedback;
-   functions->DrawTransformFeedback = st_draw_transform_feedback;
 }
 
 #endif /* FEATURE_EXT_transform_feedback */
diff --git a/src/mesa/state_tracker/st_draw.c b/src/mesa/state_tracker/st_draw.c
index fd1c8ee4879..86478bbceba 100644
--- a/src/mesa/state_tracker/st_draw.c
+++ b/src/mesa/state_tracker/st_draw.c
@@ -926,7 +926,8 @@ st_draw_vbo(struct gl_context *ctx,
             const struct _mesa_index_buffer *ib,
 	    GLboolean index_bounds_valid,
             GLuint min_index,
-            GLuint max_index)
+            GLuint max_index,
+            struct gl_transform_feedback_object *tfb_vertcount)
 {
    struct st_context *st = st_context(ctx);
    struct pipe_context *pipe = st->pipe;
@@ -939,6 +940,7 @@ st_draw_vbo(struct gl_context *ctx,
 
    /* Mesa core state should have been validated already */
    assert(ctx->NewState == 0x0);
+   assert(!tfb_vertcount);
 
    if (ib) {
       /* Gallium probably doesn't want this in some cases. */
diff --git a/src/mesa/state_tracker/st_draw.h b/src/mesa/state_tracker/st_draw.h
index a7b50ce977a..2623cdbb1ff 100644
--- a/src/mesa/state_tracker/st_draw.h
+++ b/src/mesa/state_tracker/st_draw.h
@@ -55,7 +55,8 @@ st_draw_vbo(struct gl_context *ctx,
             const struct _mesa_index_buffer *ib,
 	    GLboolean index_bounds_valid,
             GLuint min_index,
-            GLuint max_index);
+            GLuint max_index,
+            struct gl_transform_feedback_object *tfb_vertcount);
 
 extern void
 st_feedback_draw_vbo(struct gl_context *ctx,
@@ -65,7 +66,8 @@ st_feedback_draw_vbo(struct gl_context *ctx,
                      const struct _mesa_index_buffer *ib,
 		     GLboolean index_bounds_valid,
                      GLuint min_index,
-                     GLuint max_index);
+                     GLuint max_index,
+                     struct gl_transform_feedback_object *tfb_vertcount);
 
 /* Internal function:
  */
diff --git a/src/mesa/state_tracker/st_draw_feedback.c b/src/mesa/state_tracker/st_draw_feedback.c
index a7e6a0f1b71..4c1e67495b7 100644
--- a/src/mesa/state_tracker/st_draw_feedback.c
+++ b/src/mesa/state_tracker/st_draw_feedback.c
@@ -97,7 +97,8 @@ st_feedback_draw_vbo(struct gl_context *ctx,
                      const struct _mesa_index_buffer *ib,
 		     GLboolean index_bounds_valid,
                      GLuint min_index,
-                     GLuint max_index)
+                     GLuint max_index,
+                     struct gl_transform_feedback_object *tfb_vertcount)
 {
    struct st_context *st = st_context(ctx);
    struct pipe_context *pipe = st->pipe;