mesa: refactor clamping controls, get rid of _ClampReadColor

v2: cosmetic changes from Brian's email

Reviewed-by: Brian Paul <brianp@vmware.com>

src/mesa/main/blend.c

@@ -782,7 +782,37 @@ _mesa_ClampColor(GLenum target, GLenum clamp)
    }
 }
 
+static GLboolean
+get_clamp_color(const struct gl_framebuffer *fb, GLenum clamp)
+{
+   if (clamp == GL_TRUE || clamp == GL_FALSE)
+      return clamp;
 
+   ASSERT(clamp == GL_FIXED_ONLY);
+   if (!fb)
+      return GL_TRUE;
+
+   return fb->_AllColorBuffersFixedPoint;
+}
+
+GLboolean
+_mesa_get_clamp_fragment_color(const struct gl_context *ctx)
+{
+   return get_clamp_color(ctx->DrawBuffer,
+                                ctx->Color.ClampFragmentColor);
+}
+
+GLboolean
+_mesa_get_clamp_vertex_color(const struct gl_context *ctx)
+{
+   return get_clamp_color(ctx->DrawBuffer, ctx->Light.ClampVertexColor);
+}
+
+GLboolean
+_mesa_get_clamp_read_color(const struct gl_context *ctx)
+{
+   return get_clamp_color(ctx->ReadBuffer, ctx->Color.ClampReadColor);
+}
 
 
 /**********************************************************************/
@@ -835,7 +865,6 @@ void _mesa_init_color( struct gl_context * ctx )
    ctx->Color.ClampFragmentColor = GL_FIXED_ONLY_ARB;
    ctx->Color._ClampFragmentColor = GL_TRUE;
    ctx->Color.ClampReadColor = GL_FIXED_ONLY_ARB;
-   ctx->Color._ClampReadColor = GL_TRUE;
 
    if (ctx->API == API_OPENGLES2) {
       /* GLES 3 behaves as though GL_FRAMEBUFFER_SRGB is always enabled. */

src/mesa/main/blend.h

@@ -99,6 +99,14 @@ _mesa_ColorMaski( GLuint buf, GLboolean red, GLboolean green,
 extern void GLAPIENTRY
 _mesa_ClampColor(GLenum target, GLenum clamp);
 
+extern GLboolean
+_mesa_get_clamp_fragment_color(const struct gl_context *ctx);
+
+extern GLboolean
+_mesa_get_clamp_vertex_color(const struct gl_context *ctx);
+
+extern GLboolean
+_mesa_get_clamp_read_color(const struct gl_context *ctx);
 
 extern void  
 _mesa_init_color( struct gl_context * ctx );

src/mesa/main/fbobject.c

@@ -784,6 +784,7 @@ _mesa_test_framebuffer_completeness(struct gl_context *ctx,
    numImages = 0;
    fb->Width = 0;
    fb->Height = 0;
+   fb->_AllColorBuffersFixedPoint = GL_TRUE;
 
    /* Start at -2 to more easily loop over all attachment points.
     *  -2: depth buffer
@@ -900,6 +901,15 @@ _mesa_test_framebuffer_completeness(struct gl_context *ctx,
       /* check if integer color */
       fb->_IntegerColor = _mesa_is_format_integer_color(attFormat);
 
+      /* Update _AllColorBuffersFixedPoint. */
+      if (i >= 0) {
+         GLenum type = _mesa_get_format_datatype(attFormat);
+
+         fb->_AllColorBuffersFixedPoint =
+            fb->_AllColorBuffersFixedPoint &&
+            (type == GL_UNSIGNED_NORMALIZED || type == GL_SIGNED_NORMALIZED);
+      }
+
       /* Error-check width, height, format */
       if (numImages == 1) {
          /* save format */

src/mesa/main/framebuffer.c

@@ -154,6 +154,7 @@ _mesa_initialize_window_framebuffer(struct gl_framebuffer *fb,
 
    fb->Delete = _mesa_destroy_framebuffer;
    fb->_Status = GL_FRAMEBUFFER_COMPLETE_EXT;
+   fb->_AllColorBuffersFixedPoint = !visual->floatMode;
 
    compute_depth_max(fb);
 }

src/mesa/main/mtypes.h

@@ -673,7 +673,6 @@ struct gl_colorbuffer_attrib
    GLenum ClampFragmentColor; /**< GL_TRUE, GL_FALSE or GL_FIXED_ONLY_ARB */
    GLboolean _ClampFragmentColor; /** < with GL_FIXED_ONLY_ARB resolved */
    GLenum ClampReadColor;     /**< GL_TRUE, GL_FALSE or GL_FIXED_ONLY_ARB */
-   GLboolean _ClampReadColor;     /** < with GL_FIXED_ONLY_ARB resolved */
 
    GLboolean sRGBEnabled;	/**< Framebuffer sRGB blending/updating requested */
 };
@@ -2661,6 +2660,9 @@ struct gl_framebuffer
    /** Integer color values */
    GLboolean _IntegerColor;
 
+   /* ARB_color_buffer_float */
+   GLboolean _AllColorBuffersFixedPoint; /* no integer, no float */
+
    /** Array of all renderbuffer attachments, indexed by BUFFER_* tokens. */
    struct gl_renderbuffer_attachment Attachment[BUFFER_COUNT];
 

src/mesa/main/readpix.c

@@ -24,6 +24,7 @@
 
 #include "glheader.h"
 #include "imports.h"
+#include "blend.h"
 #include "bufferobj.h"
 #include "context.h"
 #include "enums.h"
@@ -80,7 +81,7 @@ get_readpixels_transfer_ops(const struct gl_context *ctx, gl_format texFormat,
    if (uses_blit) {
       /* For blit-based ReadPixels packing, the clamping is done automatically
        * unless the type is float. */
-      if (ctx->Color._ClampReadColor == GL_TRUE &&
+      if (_mesa_get_clamp_read_color(ctx) &&
           (type == GL_FLOAT || type == GL_HALF_FLOAT)) {
          transferOps |= IMAGE_CLAMP_BIT;
       }
@@ -88,7 +89,7 @@ get_readpixels_transfer_ops(const struct gl_context *ctx, gl_format texFormat,
    else {
       /* For CPU-based ReadPixels packing, the clamping must always be done
        * for non-float types, */
-      if (ctx->Color._ClampReadColor == GL_TRUE ||
+      if (_mesa_get_clamp_read_color(ctx) ||
           (type != GL_FLOAT && type != GL_HALF_FLOAT)) {
          transferOps |= IMAGE_CLAMP_BIT;
       }

src/mesa/main/state.c

@@ -51,6 +51,7 @@
 #include "texobj.h"
 #include "texstate.h"
 #include "varray.h"
+#include "blend.h"
 
 
 static void
@@ -313,11 +314,7 @@ update_multisample(struct gl_context *ctx)
 static void
 update_clamp_fragment_color(struct gl_context *ctx)
 {
-   if (ctx->Color.ClampFragmentColor == GL_FIXED_ONLY_ARB)
-      ctx->Color._ClampFragmentColor =
-         !ctx->DrawBuffer || !ctx->DrawBuffer->Visual.floatMode;
-   else
-      ctx->Color._ClampFragmentColor = ctx->Color.ClampFragmentColor;
+   ctx->Color._ClampFragmentColor = _mesa_get_clamp_fragment_color(ctx);
 }
 
 
@@ -327,27 +324,10 @@ update_clamp_fragment_color(struct gl_context *ctx)
 static void
 update_clamp_vertex_color(struct gl_context *ctx)
 {
-   if (ctx->Light.ClampVertexColor == GL_FIXED_ONLY_ARB)
-      ctx->Light._ClampVertexColor =
-         !ctx->DrawBuffer || !ctx->DrawBuffer->Visual.floatMode;
-   else
-      ctx->Light._ClampVertexColor = ctx->Light.ClampVertexColor;
+   ctx->Light._ClampVertexColor = _mesa_get_clamp_vertex_color(ctx);
 }
 
 
-/**
- * Update the ctx->Color._ClampReadColor field
- */
-static void
-update_clamp_read_color(struct gl_context *ctx)
-{
-   if (ctx->Color.ClampReadColor == GL_FIXED_ONLY_ARB)
-      ctx->Color._ClampReadColor =
-         !ctx->ReadBuffer || !ctx->ReadBuffer->Visual.floatMode;
-   else
-      ctx->Color._ClampReadColor = ctx->Color.ClampReadColor;
-}
-
 /**
  * Update the ctx->VertexProgram._TwoSideEnabled flag.
  */
@@ -525,9 +505,6 @@ _mesa_update_state_locked( struct gl_context *ctx )
    if (new_state & (_NEW_MULTISAMPLE | _NEW_BUFFERS))
       update_multisample( ctx );
 
-   if (new_state & (_NEW_COLOR | _NEW_BUFFERS))
-      update_clamp_read_color(ctx);
-
    if(new_state & (_NEW_FRAG_CLAMP | _NEW_BUFFERS))
       update_clamp_fragment_color(ctx);