mesa: implement clamping controls (ARB_color_buffer_float)

Squashed commit of the following:

Author: Marek Olšák <[email protected]>

    mesa: fix getteximage so that it doesn't clamp values
    mesa: update the compute_version function
    mesa: add display list support for ARB_color_buffer_float
    mesa: fix glGet query with GL_ALPHA_TEST_REF and ARB_color_buffer_float

commit b2f6ddf907935b2594d2831ddab38cf57a1729ce
Author: Luca Barbieri <[email protected]>
Date:   Tue Aug 31 16:50:57 2010 +0200

    mesa: document known possible deviations from ARB_color_buffer_float

commit 5458935be800c1b19d1c9d1569dc4fa30a97e8b8
Author: Luca Barbieri <[email protected]>
Date:   Tue Aug 24 21:54:56 2010 +0200

    mesa: expose GL_ARB_color_buffer_float

commit aef5c3c6be6edd076e955e37c80905bc447f8a82
Author: Luca Barbieri <[email protected]>
Date:   Thu Aug 26 18:12:34 2010 +0200

    mesa, mesa/st: handle read color clamping properly

    (I'll squash the st/mesa part to a separate commit. -Marek)

    We set IMAGE_CLAMP_BIT in the caller based on _ClampReadColor, where
    the operation mandates it.

    TODO: did I get the set of operations mandating it right?

commit 3a9cb5e59b676b6148c50907ce6eef5441677e36
Author: Luca Barbieri <[email protected]>
Date:   Thu Aug 26 18:09:41 2010 +0200

    mesa: respect color clamping in texenv programs (v2)

    Changes in v2:
    - Fix attributes other than vertex color sometimes getting clamped

commit de26f9e47e886e176aab6e5a2c3d4481efb64362
Author: Luca Barbieri <[email protected]>
Date:   Thu Aug 26 18:05:53 2010 +0200

    mesa: restore color clamps on glPopAttrib

commit a55ac3c300c189616627c05d924c40a8b55bfafa
Author: Luca Barbieri <[email protected]>
Date:   Thu Aug 26 18:04:26 2010 +0200

    mesa: clamp color queries if and only if fragment clamping is enabled

commit 9940a3e31c2fb76cc3d28b15ea78dde369825107
Author: Luca Barbieri <[email protected]>
Date:   Wed Aug 25 00:00:16 2010 +0200

    mesa: introduce derived _ClampXxxColor state resolving FIXED_ONLY

    To do this, we make ClampColor call FLUSH_VERTICES with the appropriate
    _NEW flag.

    We introduce _NEW_FRAG_CLAMP since fragment clamping has wide-ranging
    effects, despite being in the Color attrib group.

    This may be easily changed by s/_NEW_FRAG_CLAMP/_NEW_COLOR/g

commit 6244c446e3beed5473b4e811d10787e4019f59d6
Author: Luca Barbieri <[email protected]>
Date:   Thu Aug 26 17:58:24 2010 +0200

    mesa: add unclamped color parameters

1 files changed, 24 insertions, 13 deletions

diff --git a/src/mesa/main/blend.c b/src/mesa/main/blend.c
index c74a168036a..95c101c34ae 100644
--- a/src/mesa/main/blend.c
+++ b/src/mesa/main/blend.c
@@ -513,19 +513,24 @@ _mesa_BlendColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
    GET_CURRENT_CONTEXT(ctx);
    ASSERT_OUTSIDE_BEGIN_END(ctx);
 
-   tmp[0] = CLAMP( red,   0.0F, 1.0F );
-   tmp[1] = CLAMP( green, 0.0F, 1.0F );
-   tmp[2] = CLAMP( blue,  0.0F, 1.0F );
-   tmp[3] = CLAMP( alpha, 0.0F, 1.0F );
+   tmp[0] = red;
+   tmp[1] = green;
+   tmp[2] = blue;
+   tmp[3] = alpha;
 
-   if (TEST_EQ_4V(tmp, ctx->Color.BlendColor))
+   if (TEST_EQ_4V(tmp, ctx->Color.BlendColorUnclamped))
       return;
 
    FLUSH_VERTICES(ctx, _NEW_COLOR);
-   COPY_4FV( ctx->Color.BlendColor, tmp );
+   COPY_4FV( ctx->Color.BlendColorUnclamped, tmp );
+
+   ctx->Color.BlendColor[0] = CLAMP(tmp[0], 0.0F, 1.0F);
+   ctx->Color.BlendColor[1] = CLAMP(tmp[1], 0.0F, 1.0F);
+   ctx->Color.BlendColor[2] = CLAMP(tmp[2], 0.0F, 1.0F);
+   ctx->Color.BlendColor[3] = CLAMP(tmp[3], 0.0F, 1.0F);
 
    if (ctx->Driver.BlendColor)
-      (*ctx->Driver.BlendColor)(ctx, tmp);
+      (*ctx->Driver.BlendColor)(ctx, ctx->Color.BlendColor);
 }
 
 
@@ -558,17 +563,16 @@ _mesa_AlphaFunc( GLenum func, GLclampf ref )
    case GL_NOTEQUAL:
    case GL_GEQUAL:
    case GL_ALWAYS:
-      ref = CLAMP(ref, 0.0F, 1.0F);
-
-      if (ctx->Color.AlphaFunc == func && ctx->Color.AlphaRef == ref)
+      if (ctx->Color.AlphaFunc == func && ctx->Color.AlphaRefUnclamped == ref)
          return; /* no change */
 
       FLUSH_VERTICES(ctx, _NEW_COLOR);
       ctx->Color.AlphaFunc = func;
-      ctx->Color.AlphaRef = ref;
+      ctx->Color.AlphaRefUnclamped = ref;
+      ctx->Color.AlphaRef = CLAMP(ref, 0.0F, 1.0F);
 
       if (ctx->Driver.AlphaFunc)
-         ctx->Driver.AlphaFunc(ctx, func, ref);
+         ctx->Driver.AlphaFunc(ctx, func, ctx->Color.AlphaRef);
       return;
 
    default:
@@ -737,7 +741,7 @@ _mesa_ColorMaskIndexed( GLuint buf, GLboolean red, GLboolean green,
 }
 
 
-extern void GLAPIENTRY
+void GLAPIENTRY
 _mesa_ClampColorARB(GLenum target, GLenum clamp)
 {
    GET_CURRENT_CONTEXT(ctx);
@@ -751,12 +755,15 @@ _mesa_ClampColorARB(GLenum target, GLenum clamp)
 
    switch (target) {
    case GL_CLAMP_VERTEX_COLOR_ARB:
+      FLUSH_VERTICES(ctx, _NEW_LIGHT);
       ctx->Light.ClampVertexColor = clamp;
       break;
    case GL_CLAMP_FRAGMENT_COLOR_ARB:
+      FLUSH_VERTICES(ctx, _NEW_FRAG_CLAMP);
       ctx->Color.ClampFragmentColor = clamp;
       break;
    case GL_CLAMP_READ_COLOR_ARB:
+      FLUSH_VERTICES(ctx, _NEW_COLOR);
       ctx->Color.ClampReadColor = clamp;
       break;
    default:
@@ -789,6 +796,7 @@ void _mesa_init_color( struct gl_context * ctx )
    memset(ctx->Color.ColorMask, 0xff, sizeof(ctx->Color.ColorMask));
    ctx->Color.ClearIndex = 0;
    ASSIGN_4V( ctx->Color.ClearColor, 0, 0, 0, 0 );
+   ASSIGN_4V( ctx->Color.ClearColorUnclamped, 0, 0, 0, 0 );
    ctx->Color.AlphaEnabled = GL_FALSE;
    ctx->Color.AlphaFunc = GL_ALWAYS;
    ctx->Color.AlphaRef = 0;
@@ -802,6 +810,7 @@ void _mesa_init_color( struct gl_context * ctx )
       ctx->Color.Blend[i].EquationA = GL_FUNC_ADD;
    }
    ASSIGN_4V( ctx->Color.BlendColor, 0.0, 0.0, 0.0, 0.0 );
+   ASSIGN_4V( ctx->Color.BlendColorUnclamped, 0.0, 0.0, 0.0, 0.0 );
    ctx->Color.IndexLogicOpEnabled = GL_FALSE;
    ctx->Color.ColorLogicOpEnabled = GL_FALSE;
    ctx->Color._LogicOpEnabled = GL_FALSE;
@@ -816,7 +825,9 @@ 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;
 }
 
 /*@}*/