gallium: allow choosing which colorbuffers to clear

Required for glClearBuffer, which only clears one colorbuffer attachment.

Example:
   If the first colorbuffer is float and the second one is int:
      pipe->clear(pipe, PIPE_CLEAR_COLOR0, float_clear_color, ...);
      pipe->clear(pipe, PIPE_CLEAR_COLOR1, int_clear_color, ...);

This doesn't need any driver changes yet, because all drivers just use:
  if (flags & PIPE_CLEAR_COLOR) ..

The drivers which support GL 3.0 will have to implement it properly though.

6 files changed, 23 insertions, 11 deletions

diff --git a/src/gallium/auxiliary/postprocess/pp_mlaa.c b/src/gallium/auxiliary/postprocess/pp_mlaa.c
index 92bd11c5980..4f0c156f0b8 100644
--- a/src/gallium/auxiliary/postprocess/pp_mlaa.c
+++ b/src/gallium/auxiliary/postprocess/pp_mlaa.c
@@ -138,7 +138,7 @@ pp_jimenezmlaa_run(struct pp_queue_t *ppq, struct pipe_resource *in,
    pp_filter_set_fb(p);
    pp_filter_misc_state(p);
    cso_set_depth_stencil_alpha(p->cso, &mstencil);
-   p->pipe->clear(p->pipe, PIPE_CLEAR_STENCIL | PIPE_CLEAR_COLOR,
+   p->pipe->clear(p->pipe, PIPE_CLEAR_STENCIL | PIPE_CLEAR_COLOR0,
                   &p->clear_color, 0, 0);
 
    cso_single_sampler(p->cso, PIPE_SHADER_FRAGMENT, 0, &p->sampler_point);
diff --git a/src/gallium/auxiliary/postprocess/pp_run.c b/src/gallium/auxiliary/postprocess/pp_run.c
index 5c6dfa11cde..a4dc75dd71c 100644
--- a/src/gallium/auxiliary/postprocess/pp_run.c
+++ b/src/gallium/auxiliary/postprocess/pp_run.c
@@ -309,5 +309,5 @@ void
 pp_filter_set_clear_fb(struct pp_program *p)
 {
    cso_set_framebuffer(p->cso, &p->framebuffer);
-   p->pipe->clear(p->pipe, PIPE_CLEAR_COLOR, &p->clear_color, 0, 0);
+   p->pipe->clear(p->pipe, PIPE_CLEAR_COLOR0, &p->clear_color, 0, 0);
 }
diff --git a/src/gallium/auxiliary/util/u_clear.h b/src/gallium/auxiliary/util/u_clear.h
index e9fd874b1fc..75047c16b93 100644
--- a/src/gallium/auxiliary/util/u_clear.h
+++ b/src/gallium/auxiliary/util/u_clear.h
@@ -42,9 +42,10 @@ util_clear(struct pipe_context *pipe,
            struct pipe_framebuffer_state *framebuffer, unsigned buffers,
            const union pipe_color_union *color, double depth, unsigned stencil)
 {
-   if (buffers & PIPE_CLEAR_COLOR) {
-      unsigned i;
-      for (i = 0; i < framebuffer->nr_cbufs; i++) {
+   unsigned i;
+
+   for (i = 0; i < framebuffer->nr_cbufs; i++) {
+      if (buffers & (PIPE_CLEAR_COLOR0 << i)) {
          struct pipe_surface *ps = framebuffer->cbufs[i];
          pipe->clear_render_target(pipe, ps, color, 0, 0, ps->width, ps->height);
       }
diff --git a/src/gallium/drivers/r300/r300_blit.c b/src/gallium/drivers/r300/r300_blit.c
index 42410fe7dae..a0b4573d0bd 100644
--- a/src/gallium/drivers/r300/r300_blit.c
+++ b/src/gallium/drivers/r300/r300_blit.c
@@ -130,7 +130,7 @@ static boolean r300_cbzb_clear_allowed(struct r300_context *r300,
         (struct pipe_framebuffer_state*)r300->fb_state.state;
 
     /* Only color clear allowed, and only one colorbuffer. */
-    if (clear_buffers != PIPE_CLEAR_COLOR || fb->nr_cbufs != 1)
+    if ((clear_buffers & ~PIPE_CLEAR_COLOR) != 0 || fb->nr_cbufs != 1)
         return FALSE;
 
     return r300_surface(fb->cbufs[0])->cbzb_allowed;
diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
index 06a9edd2714..982f52969cf 100644
--- a/src/gallium/include/pipe/p_defines.h
+++ b/src/gallium/include/pipe/p_defines.h
@@ -188,11 +188,22 @@ enum pipe_texture_target {
 /**
  * Clear buffer bits
  */
+#define PIPE_CLEAR_DEPTH        (1 << 0)
+#define PIPE_CLEAR_STENCIL      (1 << 1)
+#define PIPE_CLEAR_COLOR0       (1 << 2)
+#define PIPE_CLEAR_COLOR1       (1 << 3)
+#define PIPE_CLEAR_COLOR2       (1 << 4)
+#define PIPE_CLEAR_COLOR3       (1 << 5)
+#define PIPE_CLEAR_COLOR4       (1 << 6)
+#define PIPE_CLEAR_COLOR5       (1 << 7)
+#define PIPE_CLEAR_COLOR6       (1 << 8)
+#define PIPE_CLEAR_COLOR7       (1 << 9)
+/** Combined flags */
 /** All color buffers currently bound */
-#define PIPE_CLEAR_COLOR        (1 << 0)
-#define PIPE_CLEAR_DEPTH        (1 << 1)
-#define PIPE_CLEAR_STENCIL      (1 << 2)
-/** Depth/stencil combined */
+#define PIPE_CLEAR_COLOR        (PIPE_CLEAR_COLOR0 | PIPE_CLEAR_COLOR1 | \
+                                 PIPE_CLEAR_COLOR2 | PIPE_CLEAR_COLOR3 | \
+                                 PIPE_CLEAR_COLOR4 | PIPE_CLEAR_COLOR5 | \
+                                 PIPE_CLEAR_COLOR6 | PIPE_CLEAR_COLOR7)
 #define PIPE_CLEAR_DEPTHSTENCIL (PIPE_CLEAR_DEPTH | PIPE_CLEAR_STENCIL)
 
 /**
diff --git a/src/gallium/state_trackers/vega/api_masks.c b/src/gallium/state_trackers/vega/api_masks.c
index 0ddcdfb75c1..48dc8445c02 100644
--- a/src/gallium/state_trackers/vega/api_masks.c
+++ b/src/gallium/state_trackers/vega/api_masks.c
@@ -97,7 +97,7 @@ void vegaClear(VGint x, VGint y,
       clear_color.f[1] = ctx->state.vg.clear_color[1];
       clear_color.f[2] = ctx->state.vg.clear_color[2];
       clear_color.f[3] = ctx->state.vg.clear_color[3];
-      ctx->pipe->clear(ctx->pipe, PIPE_CLEAR_COLOR | PIPE_CLEAR_DEPTHSTENCIL,
+      ctx->pipe->clear(ctx->pipe, PIPE_CLEAR_COLOR0 | PIPE_CLEAR_DEPTHSTENCIL,
                        &clear_color, 1., 0);
    } else if (renderer_clear_begin(ctx->renderer)) {
       /* XXX verify coord round-off */