[virglrenderer-devel] [PATCH 2/3] fix rewriting of non-alpha formats

[Erik Faye-Lund]

When we use independent blending, we need to check every rendertarget
indevidually, not just once for all, otherwise we end up using the
wrong blend-mode for some render-targets.

Fixes these test-cases:
dEQP-GLES31.functional.draw_buffers_indexed.random.max_implementation_draw_buffers.0
dEQP-GLES31.functional.draw_buffers_indexed.random.max_implementation_draw_buffers.6
dEQP-GLES31.functional.draw_buffers_indexed.random.max_implementation_draw_buffers.14

Signed-off-by: Erik Faye-Lund <erik.faye-lund at collabora.com>
---
 src/vrend_renderer.c | 52 ++++++++++++++++----------------------------
 1 file changed, 19 insertions(+), 33 deletions(-)

diff --git a/src/vrend_renderer.c b/src/vrend_renderer.c
index 3b3982b..c19ab45 100644
--- a/src/vrend_renderer.c
+++ b/src/vrend_renderer.c
@@ -3631,46 +3631,32 @@ static void vrend_patch_blend_state(struct vrend_context *ctx)
 {
    struct pipe_blend_state new_state = ctx->sub->blend_state;
    struct pipe_blend_state *state = &ctx->sub->blend_state;
-   bool dest_alpha_only = false, dest_has_no_alpha = false;
    int i;
 
    if (ctx->sub->nr_cbufs == 0)
       return;
 
-   for (i = 0; i < ctx->sub->nr_cbufs; i++) {
-      if (!ctx->sub->surf[i])
-         continue;
-
-      if (vrend_format_is_emulated_alpha(ctx->sub->surf[i]->format)) {
-         dest_alpha_only = true;
-      }
-
-      if (!util_format_has_alpha(ctx->sub->surf[i]->format)) {
-         dest_has_no_alpha = true;
-      }
-   }
-
-   if (dest_alpha_only) {
-      for (i = 0; i < (state->independent_blend_enable ? PIPE_MAX_COLOR_BUFS : 1); i++) {
-         if (state->rt[i].blend_enable) {
-            new_state.rt[i].rgb_src_factor = conv_a8_blend(state->rt[i].alpha_src_factor);
-            new_state.rt[i].rgb_dst_factor = conv_a8_blend(state->rt[i].alpha_dst_factor);
-            new_state.rt[i].alpha_src_factor = PIPE_BLENDFACTOR_ZERO;
-            new_state.rt[i].alpha_dst_factor = PIPE_BLENDFACTOR_ZERO;
+   for (i = 0; i < (state->independent_blend_enable ? PIPE_MAX_COLOR_BUFS : 1); i++) {
+      if (i < ctx->sub->nr_cbufs && ctx->sub->surf[i]) {
+         if (vrend_format_is_emulated_alpha(ctx->sub->surf[i]->format)) {
+            if (state->rt[i].blend_enable) {
+               new_state.rt[i].rgb_src_factor = conv_a8_blend(state->rt[i].alpha_src_factor);
+               new_state.rt[i].rgb_dst_factor = conv_a8_blend(state->rt[i].alpha_dst_factor);
+               new_state.rt[i].alpha_src_factor = PIPE_BLENDFACTOR_ZERO;
+               new_state.rt[i].alpha_dst_factor = PIPE_BLENDFACTOR_ZERO;
+            }
+         } else if (!util_format_has_alpha(ctx->sub->surf[i]->format)) {
+            if (!(is_dst_blend(state->rt[i].rgb_src_factor) ||
+                  is_dst_blend(state->rt[i].rgb_dst_factor) ||
+                  is_dst_blend(state->rt[i].alpha_src_factor) ||
+                  is_dst_blend(state->rt[i].alpha_dst_factor)))
+               continue;
+            new_state.rt[i].rgb_src_factor = conv_dst_blend(state->rt[i].rgb_src_factor);
+            new_state.rt[i].rgb_dst_factor = conv_dst_blend(state->rt[i].rgb_dst_factor);
+            new_state.rt[i].alpha_src_factor = conv_dst_blend(state->rt[i].alpha_src_factor);
+            new_state.rt[i].alpha_dst_factor = conv_dst_blend(state->rt[i].alpha_dst_factor);
          }
       }
-   } else if (dest_has_no_alpha) {
-      for (i = 0; i < (state->independent_blend_enable ? PIPE_MAX_COLOR_BUFS : 1); i++) {
-         if (!(is_dst_blend(state->rt[i].rgb_src_factor) ||
-               is_dst_blend(state->rt[i].rgb_dst_factor) ||
-               is_dst_blend(state->rt[i].alpha_src_factor) ||
-               is_dst_blend(state->rt[i].alpha_dst_factor)))
-            continue;
-         new_state.rt[i].rgb_src_factor = conv_dst_blend(state->rt[i].rgb_src_factor);
-         new_state.rt[i].rgb_dst_factor = conv_dst_blend(state->rt[i].rgb_dst_factor);
-         new_state.rt[i].alpha_src_factor = conv_dst_blend(state->rt[i].alpha_src_factor);
-         new_state.rt[i].alpha_dst_factor = conv_dst_blend(state->rt[i].alpha_dst_factor);
-      }
    }
 
    vrend_hw_emit_blend(ctx, &new_state);
-- 
2.18.0.rc2