python: Allow writing to buffers.

src/gallium/state_trackers/python/gallium.i

@@ -65,8 +65,7 @@
 %rename(Context) st_context;
 %rename(Texture) pipe_texture;
 %rename(Surface) pipe_surface;
-
-%rename(Buffer) pipe_buffer;
+%rename(Buffer) st_buffer;
 
 %rename(BlendColor) pipe_blend_color;
 %rename(Blend) pipe_blend_state;
@@ -88,13 +87,13 @@
 %nodefaultctor st_context;
 %nodefaultctor pipe_texture;
 %nodefaultctor pipe_surface;
-%nodefaultctor pipe_buffer;
+%nodefaultctor st_buffer;
 
 %nodefaultdtor st_device;
 %nodefaultdtor st_context;
 %nodefaultdtor pipe_texture;
 %nodefaultdtor pipe_surface;
-%nodefaultdtor pipe_buffer;
+%nodefaultdtor st_buffer;
 
 %ignore pipe_texture::screen;
 
@@ -114,6 +113,9 @@ struct st_device {
 struct st_context {
 };
 
+struct st_buffer {
+};
+
 
 %newobject st_device::texture_create;
 %newobject st_device::context_create;
@@ -197,9 +199,9 @@ struct st_context {
       return $self->screen->texture_create($self->screen, &templat);
    }
    
-   struct pipe_buffer *
+   struct st_buffer *
    buffer_create(unsigned size, unsigned alignment = 0, unsigned usage = 0) {
-      return $self->screen->winsys->buffer_create($self->screen->winsys, alignment, usage, size);
+      return st_buffer_create($self, alignment, usage, size);
    }
 
 };
@@ -323,10 +325,10 @@ struct st_context {
       $self->pipe->draw_arrays($self->pipe, mode, start, count);
    }
 
-   void draw_elements( struct pipe_buffer *indexBuffer,
+   void draw_elements( struct st_buffer *indexBuffer,
                        unsigned indexSize,
                        unsigned mode, unsigned start, unsigned count) {
-      $self->pipe->draw_elements($self->pipe, indexBuffer, indexSize, mode, start, count);
+      $self->pipe->draw_elements($self->pipe, indexBuffer->buffer, indexSize, mode, start, count);
    }
 
    void draw_vertices(unsigned prim,
@@ -522,6 +524,25 @@ error1:
 };
 
 
+%extend st_buffer {
+   
+   ~st_buffer() {
+      st_buffer_destroy($self);
+   }
+   
+   void write( const char *STRING, unsigned LENGTH, unsigned offset = 0) {
+      struct pipe_winsys *winsys = $self->st_dev->screen->winsys;
+      char *map;
+      
+      map = winsys->buffer_map(winsys, $self->buffer, PIPE_BUFFER_USAGE_CPU_WRITE);
+      if(!map) {
+         memcpy(map + offset, STRING, LENGTH);
+         winsys->buffer_unmap(winsys, $self->buffer);
+      }
+   }
+};
+
+
 %extend pipe_framebuffer_state {
    
    pipe_framebuffer_state(void) {

src/gallium/state_trackers/python/st_device.c

@@ -266,3 +266,36 @@ st_context_create(struct st_device *st_dev)
 
    return st_ctx;
 }
+
+
+void
+st_buffer_destroy(struct st_buffer *st_buf)
+{
+   if(st_buf) {
+      struct pipe_winsys *winsys = st_buf->st_dev->screen->winsys;
+      pipe_buffer_reference(winsys, &st_buf->buffer, NULL);
+      FREE(st_buf);
+   }
+}
+
+
+struct st_buffer *
+st_buffer_create(struct st_device *st_dev,
+                 unsigned alignment, unsigned usage, unsigned size)
+{
+   struct pipe_winsys *winsys = st_dev->screen->winsys;
+   struct st_buffer *st_buf;
+   
+   st_buf = CALLOC_STRUCT(st_buffer);
+   if(!st_buf)
+      return NULL;
+
+   st_buf->st_dev = st_dev;
+   
+   st_buf->buffer = winsys->buffer_create(winsys, alignment, usage, size);
+   if(!st_buf->buffer)
+      st_buffer_destroy(st_buf);
+   
+   return st_buf;
+}
+

src/gallium/state_trackers/python/st_device.h

@@ -38,6 +38,13 @@ struct pipe_context;
 struct st_winsys; 
 
 
+struct st_buffer {
+   struct st_device *st_dev;
+   
+   struct pipe_buffer *buffer;
+};
+
+
 struct st_context {
    struct st_device *st_dev;
    
@@ -65,6 +72,13 @@ struct st_device {
 };
 
 
+struct st_buffer *
+st_buffer_create(struct st_device *st_dev,
+                 unsigned alignment, unsigned usage, unsigned size);
+
+void
+st_buffer_destroy(struct st_buffer *st_buf);
+
 struct st_context *
 st_context_create(struct st_device *st_dev);