+/****************************************************************************
+ * Two-sided stencil reference value fallback. It's designed to be as much
+ * separate from rest of the driver as possible.
+ ***************************************************************************/
+
+struct r300_stencilref_context {
+ void (*draw_arrays)(struct pipe_context *pipe,
+ unsigned mode, unsigned start, unsigned count);
+
+ void (*draw_range_elements)(
+ struct pipe_context *pipe, struct pipe_resource *indexBuffer,
+ unsigned indexSize, int indexBias, unsigned minIndex, unsigned maxIndex,
+ unsigned mode, unsigned start, unsigned count);
+
+ uint32_t rs_cull_mode;
+ uint32_t zb_stencilrefmask;
+ ubyte ref_value_front;
+};
+
+static boolean r300_stencilref_needed(struct r300_context *r300)
+{
+ struct r300_dsa_state *dsa = (struct r300_dsa_state*)r300->dsa_state.state;
+
+ return dsa->two_sided_stencil_ref ||
+ (dsa->two_sided &&
+ r300->stencil_ref.ref_value[0] != r300->stencil_ref.ref_value[1]);
+}
+
+/* Set drawing for front faces. */
+static void r300_stencilref_begin(struct r300_context *r300)
+{
+ struct r300_stencilref_context *sr = r300->stencilref_fallback;
+ struct r300_rs_state *rs = (struct r300_rs_state*)r300->rs_state.state;
+ struct r300_dsa_state *dsa = (struct r300_dsa_state*)r300->dsa_state.state;
+
+ /* Save state. */
+ sr->rs_cull_mode = rs->cull_mode;
+ sr->zb_stencilrefmask = dsa->stencil_ref_mask;
+ sr->ref_value_front = r300->stencil_ref.ref_value[0];
+
+ /* We *cull* pixels, therefore no need to mask out the bits. */
+ rs->cull_mode |= R300_CULL_BACK;
+
+ r300->rs_state.dirty = TRUE;
+}
+
+/* Set drawing for back faces. */
+static void r300_stencilref_switch_side(struct r300_context *r300)
+{
+ struct r300_stencilref_context *sr = r300->stencilref_fallback;
+ struct r300_rs_state *rs = (struct r300_rs_state*)r300->rs_state.state;
+ struct r300_dsa_state *dsa = (struct r300_dsa_state*)r300->dsa_state.state;
+
+ rs->cull_mode = sr->rs_cull_mode | R300_CULL_FRONT;
+ dsa->stencil_ref_mask = dsa->stencil_ref_bf;
+ r300->stencil_ref.ref_value[0] = r300->stencil_ref.ref_value[1];
+
+ r300->rs_state.dirty = TRUE;
+ r300->dsa_state.dirty = TRUE;
+}
+
+/* Restore the original state. */
+static void r300_stencilref_end(struct r300_context *r300)
+{
+ struct r300_stencilref_context *sr = r300->stencilref_fallback;
+ struct r300_rs_state *rs = (struct r300_rs_state*)r300->rs_state.state;
+ struct r300_dsa_state *dsa = (struct r300_dsa_state*)r300->dsa_state.state;
+
+ /* Restore state. */
+ rs->cull_mode = sr->rs_cull_mode;
+ dsa->stencil_ref_mask = sr->zb_stencilrefmask;
+ r300->stencil_ref.ref_value[0] = sr->ref_value_front;
+
+ r300->rs_state.dirty = TRUE;
+ r300->dsa_state.dirty = TRUE;
+}
+
+static void r300_stencilref_draw_arrays(struct pipe_context *pipe, unsigned mode,
+ unsigned start, unsigned count)
+{
+ struct r300_context *r300 = r300_context(pipe);
+ struct r300_stencilref_context *sr = r300->stencilref_fallback;
+
+ if (!r300_stencilref_needed(r300)) {
+ sr->draw_arrays(pipe, mode, start, count);
+ } else {
+ r300_stencilref_begin(r300);
+ sr->draw_arrays(pipe, mode, start, count);
+ r300_stencilref_switch_side(r300);
+ sr->draw_arrays(pipe, mode, start, count);
+ r300_stencilref_end(r300);
+ }
+}
+
+static void r300_stencilref_draw_range_elements(
+ struct pipe_context *pipe, struct pipe_resource *indexBuffer,
+ unsigned indexSize, int indexBias, unsigned minIndex, unsigned maxIndex,
+ unsigned mode, unsigned start, unsigned count)
+{
+ struct r300_context *r300 = r300_context(pipe);
+ struct r300_stencilref_context *sr = r300->stencilref_fallback;
+
+ if (!r300_stencilref_needed(r300)) {
+ sr->draw_range_elements(pipe, indexBuffer, indexSize, indexBias,
+ minIndex, maxIndex, mode, start, count);
+ } else {
+ r300_stencilref_begin(r300);
+ sr->draw_range_elements(pipe, indexBuffer, indexSize, indexBias,
+ minIndex, maxIndex, mode, start, count);
+ r300_stencilref_switch_side(r300);
+ sr->draw_range_elements(pipe, indexBuffer, indexSize, indexBias,
+ minIndex, maxIndex, mode, start, count);
+ r300_stencilref_end(r300);
+ }
+}
+
+static void r300_plug_in_stencil_ref_fallback(struct r300_context *r300)
+{
+ r300->stencilref_fallback = CALLOC_STRUCT(r300_stencilref_context);
+
+ /* Save original draw functions. */
+ r300->stencilref_fallback->draw_arrays = r300->context.draw_arrays;
+ r300->stencilref_fallback->draw_range_elements = r300->context.draw_range_elements;
+
+ /* Override the draw functions. */
+ r300->context.draw_arrays = r300_stencilref_draw_arrays;
+ r300->context.draw_range_elements = r300_stencilref_draw_range_elements;
+}
+