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.

8 files changed, 64 insertions, 60 deletions

diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
index efdecb212aa..945f12752d3 100644
--- a/src/mesa/main/api_validate.c
+++ b/src/mesa/main/api_validate.c
@@ -474,3 +474,37 @@ _mesa_validate_DrawElementsInstanced(struct gl_context *ctx,
 
    return GL_TRUE;
 }
+
+
+#if FEATURE_EXT_transform_feedback
+
+GLboolean
+_mesa_validate_DrawTransformFeedback(struct gl_context *ctx,
+                                     GLenum mode,
+                                     struct gl_transform_feedback_object *obj)
+{
+   ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
+
+   if (!_mesa_valid_prim_mode(ctx, mode)) {
+      _mesa_error(ctx, GL_INVALID_ENUM, "glDrawTransformFeedback(mode)");
+      return GL_FALSE;
+   }
+
+   if (!obj) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glDrawTransformFeedback(name)");
+      return GL_FALSE;
+   }
+
+   if (!obj->EndedAnytime) {
+      _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawTransformFeedback");
+      return GL_FALSE;
+   }
+
+   if (!check_valid_to_render(ctx, "glDrawTransformFeedback")) {
+      return GL_FALSE;
+   }
+
+   return GL_TRUE;
+}
+
+#endif
diff --git a/src/mesa/main/api_validate.h b/src/mesa/main/api_validate.h
index 7d6a66012df..f4948424c36 100644
--- a/src/mesa/main/api_validate.h
+++ b/src/mesa/main/api_validate.h
@@ -29,9 +29,11 @@
 
 
 #include "glheader.h"
+#include "mfeatures.h"
 
 struct gl_buffer_object;
 struct gl_context;
+struct gl_transform_feedback_object;
 
 
 extern GLuint
@@ -70,5 +72,13 @@ _mesa_validate_DrawElementsInstanced(struct gl_context *ctx,
                                      const GLvoid *indices, GLsizei primcount,
                                      GLint basevertex);
 
+#if FEATURE_EXT_transform_feedback
+
+extern GLboolean
+_mesa_validate_DrawTransformFeedback(struct gl_context *ctx,
+                                     GLenum mode,
+                                     struct gl_transform_feedback_object *obj);
+
+#endif
 
 #endif
diff --git a/src/mesa/main/dd.h b/src/mesa/main/dd.h
index d6f70d1c49e..01cfff8ab7c 100644
--- a/src/mesa/main/dd.h
+++ b/src/mesa/main/dd.h
@@ -964,8 +964,6 @@ struct dd_function_table {
                                   struct gl_transform_feedback_object *obj);
    void (*ResumeTransformFeedback)(struct gl_context *ctx,
                                    struct gl_transform_feedback_object *obj);
-   void (*DrawTransformFeedback)(struct gl_context *ctx, GLenum mode,
-                                 struct gl_transform_feedback_object *obj);
 
    /**
     * \name GL_NV_texture_barrier interface
@@ -1194,6 +1192,7 @@ typedef struct {
    void (GLAPIENTRYP DrawElementsInstancedBaseVertex)(GLenum mode, GLsizei count,
                                             GLenum type, const GLvoid *indices,
                                             GLsizei primcount, GLint basevertex);
+   void (GLAPIENTRYP DrawTransformFeedback)(GLenum mode, GLuint name);
    /*@}*/
 
    /**
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 19343497689..0e29dc0dc79 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -2355,6 +2355,8 @@ struct gl_transform_feedback_object
    GLint RefCount;
    GLboolean Active;  /**< Is transform feedback enabled? */
    GLboolean Paused;  /**< Is transform feedback paused? */
+   GLboolean EndedAnytime; /**< Has EndTransformFeedback been called
+                                at least once? */
 
    /** The feedback buffers */
    GLuint BufferNames[MAX_FEEDBACK_ATTRIBS];
diff --git a/src/mesa/main/transformfeedback.c b/src/mesa/main/transformfeedback.c
index 799245d4ed5..824f66a3528 100644
--- a/src/mesa/main/transformfeedback.c
+++ b/src/mesa/main/transformfeedback.c
@@ -294,18 +294,6 @@ resume_transform_feedback(struct gl_context *ctx,
    /* nop */
 }
 
-/** Default fallback for ctx->Driver.DrawTransformFeedback() */
-static void
-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);
-    */
-}
-
 
 /**
  * Plug in default device driver functions for transform feedback.
@@ -320,7 +308,6 @@ _mesa_init_transform_feedback_functions(struct dd_function_table *driver)
    driver->EndTransformFeedback = end_transform_feedback;
    driver->PauseTransformFeedback = pause_transform_feedback;
    driver->ResumeTransformFeedback = resume_transform_feedback;
-   driver->DrawTransformFeedback = draw_transform_feedback;
 }
 
 
@@ -342,7 +329,6 @@ _mesa_init_transform_feedback_dispatch(struct _glapi_table *disp)
    SET_IsTransformFeedback(disp, _mesa_IsTransformFeedback);
    SET_PauseTransformFeedback(disp, _mesa_PauseTransformFeedback);
    SET_ResumeTransformFeedback(disp, _mesa_ResumeTransformFeedback);
-   SET_DrawTransformFeedback(disp, _mesa_DrawTransformFeedback);
 }
 
 
@@ -401,6 +387,7 @@ _mesa_EndTransformFeedback(void)
 
    FLUSH_VERTICES(ctx, _NEW_TRANSFORM_FEEDBACK);
    ctx->TransformFeedback.CurrentObject->Active = GL_FALSE;
+   ctx->TransformFeedback.CurrentObject->EndedAnytime = GL_TRUE;
 
    assert(ctx->Driver.EndTransformFeedback);
    ctx->Driver.EndTransformFeedback(ctx, obj);
@@ -714,8 +701,8 @@ _mesa_GetTransformFeedbackVarying(GLuint program, GLuint index,
 
 
 
-static struct gl_transform_feedback_object *
-lookup_transform_feedback_object(struct gl_context *ctx, GLuint name)
+struct gl_transform_feedback_object *
+_mesa_lookup_transform_feedback_object(struct gl_context *ctx, GLuint name)
 {
    if (name == 0) {
       return ctx->TransformFeedback.DefaultObject;
@@ -780,7 +767,7 @@ _mesa_IsTransformFeedback(GLuint name)
 
    ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
 
-   if (name && lookup_transform_feedback_object(ctx, name))
+   if (name && _mesa_lookup_transform_feedback_object(ctx, name))
       return GL_TRUE;
    else
       return GL_FALSE;
@@ -809,7 +796,7 @@ _mesa_BindTransformFeedback(GLenum target, GLuint name)
       return;
    }
 
-   obj = lookup_transform_feedback_object(ctx, name);
+   obj = _mesa_lookup_transform_feedback_object(ctx, name);
    if (!obj) {
       _mesa_error(ctx, GL_INVALID_OPERATION,
                   "glBindTransformFeedback(name=%u)", name);
@@ -844,7 +831,7 @@ _mesa_DeleteTransformFeedbacks(GLsizei n, const GLuint *names)
    for (i = 0; i < n; i++) {
       if (names[i] > 0) {
          struct gl_transform_feedback_object *obj
-            = lookup_transform_feedback_object(ctx, names[i]);
+            = _mesa_lookup_transform_feedback_object(ctx, names[i]);
          if (obj) {
             if (obj->Active) {
                _mesa_error(ctx, GL_INVALID_OPERATION,
@@ -912,40 +899,4 @@ _mesa_ResumeTransformFeedback(void)
    ctx->Driver.ResumeTransformFeedback(ctx, obj);
 }
 
-
-/**
- * Draw the vertex data in a transform feedback object.
- * \param mode  GL_POINTS, GL_LINES, GL_TRIANGLE_STRIP, etc.
- * \param name  the transform feedback object
- * The number of vertices comes from the transform feedback object.
- * User still has to setup of the vertex attribute info with
- * glVertexPointer, glColorPointer, etc.
- * Part of GL_ARB_transform_feedback2.
- */
-void GLAPIENTRY
-_mesa_DrawTransformFeedback(GLenum mode, GLuint name)
-{
-   GET_CURRENT_CONTEXT(ctx);
-   struct gl_transform_feedback_object *obj =
-      lookup_transform_feedback_object(ctx, name);
-
-   if (mode > GL_POLYGON) {
-      _mesa_error(ctx, GL_INVALID_ENUM,
-                  "glDrawTransformFeedback(mode=0x%x)", mode);
-      return;
-   }
-   if (!obj) {
-      _mesa_error(ctx, GL_INVALID_VALUE,
-                  "glDrawTransformFeedback(name = %u)", name);
-      return;
-   }
-
-   /* XXX check if EndTransformFeedback has never been called while
-    * the object was bound
-    */
-
-   assert(ctx->Driver.DrawTransformFeedback);
-   ctx->Driver.DrawTransformFeedback(ctx, mode, obj);
-}
-
 #endif /* FEATURE_EXT_transform_feedback */
diff --git a/src/mesa/main/transformfeedback.h b/src/mesa/main/transformfeedback.h
index 9447effa928..8a6672d58de 100644
--- a/src/mesa/main/transformfeedback.h
+++ b/src/mesa/main/transformfeedback.h
@@ -87,6 +87,9 @@ _mesa_GetTransformFeedbackVarying(GLuint program, GLuint index,
 
 /*** GL_ARB_transform_feedback2 ***/
 
+struct gl_transform_feedback_object *
+_mesa_lookup_transform_feedback_object(struct gl_context *ctx, GLuint name);
+
 extern void GLAPIENTRY
 _mesa_GenTransformFeedbacks(GLsizei n, GLuint *names);
 
@@ -105,9 +108,6 @@ _mesa_PauseTransformFeedback(void);
 extern void GLAPIENTRY
 _mesa_ResumeTransformFeedback(void);
 
-extern void GLAPIENTRY
-_mesa_DrawTransformFeedback(GLenum mode, GLuint name);
-
 #else /* FEATURE_EXT_transform_feedback */
 
 static inline GLboolean
diff --git a/src/mesa/main/varray.h b/src/mesa/main/varray.h
index 6fcc0a33627..b6041bd787e 100644
--- a/src/mesa/main/varray.h
+++ b/src/mesa/main/varray.h
@@ -245,6 +245,13 @@ _mesa_DrawRangeElementsBaseVertex(GLenum mode, GLuint start, GLuint end,
 				  const GLvoid *indices,
 				  GLint basevertex);
 
+#if FEATURE_EXT_transform_feedback
+
+extern void GLAPIENTRY
+_mesa_DrawTransformFeedback(GLenum mode, GLuint name);
+
+#endif
+
 extern void GLAPIENTRY
 _mesa_PrimitiveRestartIndex(GLuint index);
 
diff --git a/src/mesa/main/vtxfmt.c b/src/mesa/main/vtxfmt.c
index 03735d779b8..f3cca937d0c 100644
--- a/src/mesa/main/vtxfmt.c
+++ b/src/mesa/main/vtxfmt.c
@@ -107,6 +107,7 @@ install_vtxfmt( struct _glapi_table *tab, const GLvertexformat *vfmt )
    SET_DrawArraysInstancedARB(tab, vfmt->DrawArraysInstanced);
    SET_DrawElementsInstancedARB(tab, vfmt->DrawElementsInstanced);
    SET_DrawElementsInstancedBaseVertex(tab, vfmt->DrawElementsInstancedBaseVertex);
+   SET_DrawTransformFeedback(tab, vfmt->DrawTransformFeedback);
 
    /* GL_NV_vertex_program */
    SET_VertexAttrib1fNV(tab, vfmt->VertexAttrib1fNV);