draw: clear the draw buffers in draw

Moves clearing of the draw so target buffers to the draw
module. They had to be cleared in the drivers before
which was quite messy.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>

src/gallium/auxiliary/draw/draw_context.c

@@ -806,15 +806,36 @@ draw_get_rasterizer_no_cull( struct draw_context *draw,
    return draw->rasterizer_no_cull[scissor][flatshade];
 }
 
+/**
+ * Sets the mapped so targets.
+ *
+ * The append bitmask specifies which of the buffers are in
+ * the append mode. The append mode means that the buffer
+ * should be appended to, rather than written to from the start.
+ * i.e. the outputs should be written starting from the last 
+ * location to which the previous
+ * pass of stream output wrote to in this buffer.
+ * If the buffer is not in an append mode (which is more common)
+ * the writing begins from the start of the buffer.
+ *
+ */
 void
 draw_set_mapped_so_targets(struct draw_context *draw,
                            int num_targets,
-                           struct draw_so_target *targets[PIPE_MAX_SO_BUFFERS])
+                           struct draw_so_target *targets[PIPE_MAX_SO_BUFFERS],
+                           unsigned append_bitmask)
 {
    int i;
 
-   for (i = 0; i < num_targets; i++)
+   for (i = 0; i < num_targets; i++) {
       draw->so.targets[i] = targets[i];
+      /* if we're not appending then lets reset the internal
+         data of our so target */
+      if (!(append_bitmask & (1 << i)) && draw->so.targets[i]) {
+         draw->so.targets[i]->internal_offset = 0;
+         draw->so.targets[i]->emitted_vertices = 0;
+      }
+   }
    for (i = num_targets; i < PIPE_MAX_SO_BUFFERS; i++)
       draw->so.targets[i] = NULL;
 

src/gallium/auxiliary/draw/draw_context.h

@@ -231,7 +231,8 @@ draw_set_mapped_constant_buffer(struct draw_context *draw,
 void
 draw_set_mapped_so_targets(struct draw_context *draw,
                            int num_targets,
-                           struct draw_so_target *targets[PIPE_MAX_SO_BUFFERS]);
+                           struct draw_so_target *targets[PIPE_MAX_SO_BUFFERS],
+                           unsigned append_bitmask);
 
 
 /***********************************************************************

src/gallium/drivers/llvmpipe/lp_context.h

@@ -91,6 +91,7 @@ struct llvmpipe_context {
 
    struct draw_so_target *so_targets[PIPE_MAX_SO_BUFFERS];
    int num_so_targets;
+   unsigned so_append_bitmask;
    struct pipe_query_data_so_statistics so_stats;
    unsigned num_primitives_generated;
 

src/gallium/drivers/llvmpipe/lp_draw_arrays.c

@@ -104,7 +104,7 @@ llvmpipe_draw_vbo(struct pipe_context *pipe, const struct pipe_draw_info *info)
       }
    }
    draw_set_mapped_so_targets(draw, lp->num_so_targets,
-                              lp->so_targets);
+                              lp->so_targets, lp->so_append_bitmask);
 
    llvmpipe_prepare_vertex_sampling(lp,
                                     lp->num_sampler_views[PIPE_SHADER_VERTEX],
@@ -134,7 +134,7 @@ llvmpipe_draw_vbo(struct pipe_context *pipe, const struct pipe_draw_info *info)
    if (mapped_indices) {
       draw_set_indexes(draw, NULL, 0, 0);
    }
-   draw_set_mapped_so_targets(draw, 0, NULL);
+   draw_set_mapped_so_targets(draw, 0, NULL, 0);
 
    if (lp->gs && !lp->gs->shader.tokens) {
       /* we have attached stream output to the vs for rendering,

src/gallium/drivers/llvmpipe/lp_state_so.c

@@ -70,17 +70,13 @@ llvmpipe_set_so_targets(struct pipe_context *pipe,
    int i;
    for (i = 0; i < num_targets; i++) {
       pipe_so_target_reference((struct pipe_stream_output_target **)&llvmpipe->so_targets[i], targets[i]);
-      /* if we're not appending then lets reset the internal
-         data of our so target */
-      if (!(append_bitmask & (1 << i)) && llvmpipe->so_targets[i]) {
-         llvmpipe->so_targets[i]->internal_offset = 0;
-         llvmpipe->so_targets[i]->emitted_vertices = 0;
-      }
    }
 
    for (; i < llvmpipe->num_so_targets; i++) {
       pipe_so_target_reference((struct pipe_stream_output_target **)&llvmpipe->so_targets[i], NULL);
    }
+
+   llvmpipe->so_append_bitmask = append_bitmask;
    llvmpipe->num_so_targets = num_targets;
 }
 

src/gallium/drivers/softpipe/sp_context.h

@@ -88,6 +88,7 @@ struct softpipe_context {
 
    struct draw_so_target *so_targets[PIPE_MAX_SO_BUFFERS];
    unsigned num_so_targets;
+   unsigned so_append_bitmask;
    
    struct pipe_query_data_so_statistics so_stats;
    unsigned num_primitives_generated;

src/gallium/drivers/softpipe/sp_draw_arrays.c

@@ -112,7 +112,7 @@ softpipe_draw_vbo(struct pipe_context *pipe,
    }
 
    draw_set_mapped_so_targets(draw, sp->num_so_targets,
-                              sp->so_targets);
+                              sp->so_targets, sp->so_append_bitmask);
 
    if (sp->gs && !sp->gs->shader.tokens) {
       /* we have an empty geometry shader with stream output, so
@@ -135,7 +135,7 @@ softpipe_draw_vbo(struct pipe_context *pipe,
       draw_set_indexes(draw, NULL, 0, 0);
    }
 
-   draw_set_mapped_so_targets(draw, 0, NULL);
+   draw_set_mapped_so_targets(draw, 0, NULL, 0);
 
    /*
     * TODO: Flush only when a user vertex/index buffer is present

src/gallium/drivers/softpipe/sp_state_so.c

@@ -77,6 +77,7 @@ softpipe_set_so_targets(struct pipe_context *pipe,
    }
 
    softpipe->num_so_targets = num_targets;
+   softpipe->so_append_bitmask = append_bitmask;
 }
 
 void