st/mesa: implement EXT_transform_feedback and ARB_transform_feedback2

1 files changed, 109 insertions, 33 deletions

diff --git a/src/mesa/state_tracker/st_cb_xformfb.c b/src/mesa/state_tracker/st_cb_xformfb.c
index a17b54d..2fc28dc 100644
--- a/src/mesa/state_tracker/st_cb_xformfb.c
+++ b/src/mesa/state_tracker/st_cb_xformfb.c
@@ -30,70 +30,122 @@
  * Transform feedback functions.
  *
  * \author Brian Paul
+ *         Marek Olšák
  */
 
 
-#include "main/imports.h"
+#include "main/bufferobj.h"
 #include "main/context.h"
 #include "main/mfeatures.h"
 #include "main/transformfeedback.h"
 
+#include "st_cb_bufferobjects.h"
 #include "st_cb_xformfb.h"
+#include "st_context.h"
 
+#include "pipe/p_context.h"
+#include "util/u_draw.h"
+#include "util/u_inlines.h"
+#include "cso_cache/cso_context.h"
 
 #if FEATURE_EXT_transform_feedback
 
-#if 0
+struct st_transform_feedback_object {
+   struct gl_transform_feedback_object base;
+
+   unsigned num_targets;
+   struct pipe_stream_output_target *targets[PIPE_MAX_SO_BUFFERS];
+};
+
+
 static struct gl_transform_feedback_object *
 st_new_transform_feedback(struct gl_context *ctx, GLuint name)
 {
-   struct gl_transform_feedback_object *obj;
-   obj = CALLOC_STRUCT(gl_transform_feedback_object);
-   if (obj) {
-      obj->Name = name;
-      obj->RefCount = 1;
-   }
-   return obj;
+   struct st_transform_feedback_object *obj;
+
+   obj = CALLOC_STRUCT(st_transform_feedback_object);
+   if (!obj)
+      return NULL;
+
+   obj->base.Name = name;
+   obj->base.RefCount = 1;
+   return &obj->base;
 }
-#endif
 
-#if 0
+
 static void
 st_delete_transform_feedback(struct gl_context *ctx,
                              struct gl_transform_feedback_object *obj)
 {
-   GLuint i;
+   struct st_transform_feedback_object *sobj =
+         (struct st_transform_feedback_object*)obj;
+   unsigned i;
+
+   /* Unreference targets. */
+   for (i = 0; i < sobj->num_targets; i++) {
+      pipe_so_target_reference(&sobj->targets[i], NULL);
+   }
 
-   for (i = 0; i < Elements(obj->Buffers); i++) {
-      _mesa_reference_buffer_object(ctx, &obj->Buffers[i], NULL);
+   for (i = 0; i < Elements(sobj->base.Buffers); i++) {
+      _mesa_reference_buffer_object(ctx, &sobj->base.Buffers[i], NULL);
    }
 
    free(obj);
 }
-#endif
 
 
+/* XXX Do we really need the mode? */
 static void
 st_begin_transform_feedback(struct gl_context *ctx, GLenum mode,
                             struct gl_transform_feedback_object *obj)
 {
-   /* to-do */
-}
-
+   struct st_context *st = st_context(ctx);
+   struct pipe_context *pipe = st->pipe;
+   struct st_transform_feedback_object *sobj =
+         (struct st_transform_feedback_object*)obj;
+   unsigned i, max_num_targets;
+
+   max_num_targets = MIN2(Elements(sobj->base.Buffers),
+                          Elements(sobj->targets));
+
+   /* Convert the transform feedback state into the gallium representation. */
+   for (i = 0; i < max_num_targets; i++) {
+      struct st_buffer_object *bo = st_buffer_object(sobj->base.Buffers[i]);
+
+      if (bo) {
+         /* Check whether we need to recreate the target. */
+         if (!sobj->targets[i] ||
+             sobj->targets[i]->buffer != bo->buffer ||
+             sobj->targets[i]->buffer_offset != sobj->base.Offset[i] ||
+             sobj->targets[i]->buffer_size != sobj->base.Size[i]) {
+            /* Create a new target. */
+            struct pipe_stream_output_target *so_target =
+                  pipe->create_stream_output_target(pipe, bo->buffer,
+                                                    sobj->base.Offset[i],
+                                                    sobj->base.Size[i]);
+
+            pipe_so_target_reference(&sobj->targets[i], NULL);
+            sobj->targets[i] = so_target;
+         }
+
+         sobj->num_targets = i+1;
+      } else {
+         pipe_so_target_reference(&sobj->targets[i], NULL);
+      }
+   }
 
-static void
-st_end_transform_feedback(struct gl_context *ctx,
-                          struct gl_transform_feedback_object *obj)
-{
-   /* to-do */
+   /* Start writing at the beginning of each target. */
+   cso_set_stream_outputs(st->cso_context, sobj->num_targets, sobj->targets,
+                          0);
 }
 
 
 static void
-st_pause_transform_feedback(struct gl_context *ctx,
-                            struct gl_transform_feedback_object *obj)
+st_stop_transform_feedback(struct gl_context *ctx,
+                           struct gl_transform_feedback_object *obj)
 {
-   /* to-do */
+   struct st_context *st = st_context(ctx);
+   cso_set_stream_outputs(st->cso_context, 0, NULL, 0);
 }
 
 
@@ -101,20 +153,44 @@ static void
 st_resume_transform_feedback(struct gl_context *ctx,
                              struct gl_transform_feedback_object *obj)
 {
-   /* to-do */
+   struct st_context *st = st_context(ctx);
+   struct st_transform_feedback_object *sobj =
+         (struct st_transform_feedback_object*)obj;
+
+   cso_set_stream_outputs(st->cso_context, sobj->num_targets, sobj->targets,
+                          ~0);
+}
+
+/* Set count_from_stream_output to any stream output target
+ * from the transform feedback object. */
+void
+st_transform_feedback_draw_init(struct gl_transform_feedback_object *obj,
+                                struct pipe_draw_info *out)
+{
+   struct st_transform_feedback_object *sobj =
+         (struct st_transform_feedback_object*)obj;
+   unsigned i;
+
+   for (i = 0; i < Elements(sobj->targets); i++) {
+      if (sobj->targets[i]) {
+         out->count_from_stream_output = sobj->targets[i];
+         return;
+      }
+   }
+
+   assert(0);
+   out->count_from_stream_output = NULL;
 }
 
 
 void
 st_init_xformfb_functions(struct dd_function_table *functions)
 {
-   /* let core Mesa plug in its functions */
-   _mesa_init_transform_feedback_functions(functions);
-
-   /* then override a few: */
+   functions->NewTransformFeedback = st_new_transform_feedback;
+   functions->DeleteTransformFeedback = st_delete_transform_feedback;
    functions->BeginTransformFeedback = st_begin_transform_feedback;
-   functions->EndTransformFeedback = st_end_transform_feedback;
-   functions->PauseTransformFeedback = st_pause_transform_feedback;
+   functions->EndTransformFeedback = st_stop_transform_feedback;
+   functions->PauseTransformFeedback = st_stop_transform_feedback;
    functions->ResumeTransformFeedback = st_resume_transform_feedback;
 }