st/mesa: need to translate clear color according to surface's base format

When clearing a GL_LUMINANCE_ALPHA buffer, for example, we need to convert
the clear color (R,G,B,A) to (R,R,R,A).  We were doing this for texture border
colors but not renderbuffers.  Move the translation function to st_format.c
and share it.

This fixes the piglit fbo-clear-formats test.

NOTE: This is a candidate for the 7.9 and 7.10 branches.
(cherry picked from commit e2d108ec82)

Conflicts:

	src/mesa/state_tracker/st_atom_sampler.c

src/mesa/state_tracker/st_atom_sampler.c

@@ -36,6 +36,7 @@
 
 #include "st_context.h"
 #include "st_cb_texture.h"
+#include "st_format.h"
 #include "st_atom.h"
 #include "pipe/p_context.h"
 #include "pipe/p_defines.h"
@@ -117,37 +118,6 @@ gl_filter_to_img_filter(GLenum filter)
 }
 
 
-static void
-xlate_border_color(const GLfloat *colorIn, GLenum baseFormat, GLfloat *colorOut)
-{
-   switch (baseFormat) {
-   case GL_RGB:
-      colorOut[0] = colorIn[0];
-      colorOut[1] = colorIn[1];
-      colorOut[2] = colorIn[2];
-      colorOut[3] = 1.0F;
-      break;
-   case GL_ALPHA:
-      colorOut[0] = colorOut[1] = colorOut[2] = 0.0;
-      colorOut[3] = colorIn[3];
-      break;
-   case GL_LUMINANCE:
-      colorOut[0] = colorOut[1] = colorOut[2] = colorIn[0];
-      colorOut[3] = 1.0;
-      break;
-   case GL_LUMINANCE_ALPHA:
-      colorOut[0] = colorOut[1] = colorOut[2] = colorIn[0];
-      colorOut[3] = colorIn[3];
-      break;
-   case GL_INTENSITY:
-      colorOut[0] = colorOut[1] = colorOut[2] = colorOut[3] = colorIn[0];
-      break;
-   default:
-      COPY_4V(colorOut, colorIn);
-   }
-}
-
-
 static void 
 update_samplers(struct st_context *st)
 {
@@ -211,7 +181,7 @@ update_samplers(struct st_context *st)
             assert(sampler->min_lod <= sampler->max_lod);
          }
 
-         xlate_border_color(texobj->BorderColor.f,
+         st_translate_color(texobj->BorderColor.f,
                             teximg ? teximg->_BaseFormat : GL_RGBA,
                             sampler->border_color);
 

src/mesa/state_tracker/st_cb_clear.c

@@ -42,6 +42,7 @@
 #include "st_cb_accum.h"
 #include "st_cb_clear.h"
 #include "st_cb_fbo.h"
+#include "st_format.h"
 #include "st_program.h"
 
 #include "pipe/p_context.h"
@@ -202,6 +203,7 @@ clear_with_quad(GLcontext *ctx,
    const GLfloat x1 = (GLfloat) ctx->DrawBuffer->_Xmax / fb_width * 2.0f - 1.0f;
    const GLfloat y0 = (GLfloat) ctx->DrawBuffer->_Ymin / fb_height * 2.0f - 1.0f;
    const GLfloat y1 = (GLfloat) ctx->DrawBuffer->_Ymax / fb_height * 2.0f - 1.0f;
+   float clearColor[4];
 
    /*
    printf("%s %s%s%s %f,%f %f,%f\n", __FUNCTION__, 
@@ -295,9 +297,12 @@ clear_with_quad(GLcontext *ctx,
    cso_set_fragment_shader_handle(st->cso_context, st->clear.fs);
    cso_set_vertex_shader_handle(st->cso_context, st->clear.vs);
 
-   /* draw quad matching scissor rect (XXX verify coord round-off) */
-   draw_quad(st, x0, y0, x1, y1,
-             (GLfloat) ctx->Depth.Clear, ctx->Color.ClearColor);
+   st_translate_color(ctx->Color.ClearColor,
+                      ctx->DrawBuffer->_ColorDrawBuffers[0]->_BaseFormat,
+                      clearColor);
+
+   /* draw quad matching scissor rect */
+   draw_quad(st, x0, y0, x1, y1, (GLfloat) ctx->Depth.Clear, clearColor);
 
    /* Restore pipe state */
    cso_restore_blend(st->cso_context);
@@ -537,12 +542,19 @@ st_Clear(GLcontext *ctx, GLbitfield mask)
        * required from the visual. Hence fix this up to avoid potential
        * read-modify-write in the driver.
        */
+      float clearColor[4];
+
       if ((clear_buffers & PIPE_CLEAR_DEPTHSTENCIL) &&
           ((clear_buffers & PIPE_CLEAR_DEPTHSTENCIL) != PIPE_CLEAR_DEPTHSTENCIL) &&
           (depthRb == stencilRb) &&
           (ctx->DrawBuffer->Visual.depthBits == 0 ||
            ctx->DrawBuffer->Visual.stencilBits == 0))
          clear_buffers |= PIPE_CLEAR_DEPTHSTENCIL;
+
+      st_translate_color(ctx->Color.ClearColor,
+                         ctx->DrawBuffer->_ColorDrawBuffers[0]->_BaseFormat,
+                         clearColor);
+
       st->pipe->clear(st->pipe, clear_buffers, ctx->Color.ClearColor,
                       ctx->Depth.Clear, ctx->Stencil.Clear);
    }

src/mesa/state_tracker/st_format.c

@@ -800,3 +800,55 @@ st_sampler_compat_formats(enum pipe_format format1, enum pipe_format format2)
 
    return GL_FALSE;
 }
+
+
+
+/**
+ * This is used for translating texture border color and the clear
+ * color.  For example, the clear color is interpreted according to
+ * the renderbuffer's base format.  For example, if clearing a
+ * GL_LUMINANCE buffer, ClearColor[0] = luminance and ClearColor[1] =
+ * alpha.  Similarly for texture border colors.
+ */
+void
+st_translate_color(const GLfloat colorIn[4], GLenum baseFormat,
+                   GLfloat colorOut[4])
+{
+   switch (baseFormat) {
+   case GL_RED:
+      colorOut[0] = colorIn[0];
+      colorOut[1] = 0.0F;
+      colorOut[2] = 0.0F;
+      colorOut[3] = 1.0F;
+      break;
+   case GL_RG:
+      colorOut[0] = colorIn[0];
+      colorOut[1] = colorIn[1];
+      colorOut[2] = 0.0F;
+      colorOut[3] = 1.0F;
+      break;
+   case GL_RGB:
+      colorOut[0] = colorIn[0];
+      colorOut[1] = colorIn[1];
+      colorOut[2] = colorIn[2];
+      colorOut[3] = 1.0F;
+      break;
+   case GL_ALPHA:
+      colorOut[0] = colorOut[1] = colorOut[2] = 0.0;
+      colorOut[3] = colorIn[3];
+      break;
+   case GL_LUMINANCE:
+      colorOut[0] = colorOut[1] = colorOut[2] = colorIn[0];
+      colorOut[3] = 1.0;
+      break;
+   case GL_LUMINANCE_ALPHA:
+      colorOut[0] = colorOut[1] = colorOut[2] = colorIn[0];
+      colorOut[3] = colorIn[3];
+      break;
+   case GL_INTENSITY:
+      colorOut[0] = colorOut[1] = colorOut[2] = colorOut[3] = colorIn[0];
+      break;
+   default:
+      COPY_4V(colorOut, colorIn);
+   }
+}

src/mesa/state_tracker/st_format.h

@@ -72,4 +72,10 @@ st_equal_formats(enum pipe_format pFormat, GLenum format, GLenum type);
 extern GLboolean
 st_sampler_compat_formats(enum pipe_format format1, enum pipe_format format2);
 
+
+extern void
+st_translate_color(const GLfloat colorIn[4], GLenum baseFormat,
+                   GLfloat colorOut[4]);
+
+
 #endif /* ST_FORMAT_H */