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

5 files changed, 38 insertions, 7 deletions

diff --git a/src/mesa/program/arbprogparse.c b/src/mesa/program/arbprogparse.c
index ca63e72c085..7f778c3c381 100644
--- a/src/mesa/program/arbprogparse.c
+++ b/src/mesa/program/arbprogparse.c
@@ -144,7 +144,10 @@ _mesa_parse_arb_fragment_program(struct gl_context* ctx, GLenum target,
     * from the fragment shader.
     */
    if (program->FogOption != GL_NONE) {
-      _mesa_append_fog_code(ctx, program);
+      /* XXX: we should somehow recompile this to remove clamping if disabled
+       * On the ATI driver, this is unclampled if fragment clamping is disabled
+       */
+      _mesa_append_fog_code(ctx, program, GL_TRUE);
       program->FogOption = GL_NONE;
    }
 
diff --git a/src/mesa/program/prog_statevars.c b/src/mesa/program/prog_statevars.c
index c310acb01d4..384aa2cb2c6 100644
--- a/src/mesa/program/prog_statevars.c
+++ b/src/mesa/program/prog_statevars.c
@@ -237,11 +237,17 @@ _mesa_fetch_state(struct gl_context *ctx, const gl_state_index state[],
       {
          /* state[1] is the texture unit */
          const GLuint unit = (GLuint) state[1];
-         COPY_4V(value, ctx->Texture.Unit[unit].EnvColor);
+         if(ctx->Color._ClampFragmentColor)
+            COPY_4V(value, ctx->Texture.Unit[unit].EnvColor);
+         else
+            COPY_4V(value, ctx->Texture.Unit[unit].EnvColorUnclamped);
       }
       return;
    case STATE_FOG_COLOR:
-      COPY_4V(value, ctx->Fog.Color);
+      if(ctx->Color._ClampFragmentColor)
+         COPY_4V(value, ctx->Fog.Color);
+      else
+         COPY_4V(value, ctx->Fog.ColorUnclamped);
       return;
    case STATE_FOG_PARAMS:
       value[0] = ctx->Fog.Density;
@@ -399,6 +405,22 @@ _mesa_fetch_state(struct gl_context *ctx, const gl_state_index state[],
          }
          return;
 
+      case STATE_CURRENT_ATTRIB_MAYBE_VP_CLAMPED:
+         {
+            const GLuint idx = (GLuint) state[2];
+            if(ctx->Light._ClampVertexColor &&
+               (idx == VERT_ATTRIB_COLOR0 ||
+                idx == VERT_ATTRIB_COLOR1)) {
+               value[0] = CLAMP(ctx->Current.Attrib[idx][0], 0.0f, 1.0f);
+               value[1] = CLAMP(ctx->Current.Attrib[idx][1], 0.0f, 1.0f);
+               value[2] = CLAMP(ctx->Current.Attrib[idx][2], 0.0f, 1.0f);
+               value[3] = CLAMP(ctx->Current.Attrib[idx][3], 0.0f, 1.0f);
+            }
+            else
+               COPY_4V(value, ctx->Current.Attrib[idx]);
+         }
+         return;
+
       case STATE_NORMAL_SCALE:
          ASSIGN_4V(value, 
                    ctx->_ModelViewInvScale, 
@@ -649,10 +671,12 @@ _mesa_program_state_flags(const gl_state_index state[STATE_LENGTH])
       return _NEW_LIGHT;
 
    case STATE_TEXGEN:
-   case STATE_TEXENV_COLOR:
       return _NEW_TEXTURE;
+   case STATE_TEXENV_COLOR:
+      return _NEW_TEXTURE | _NEW_BUFFERS | _NEW_FRAG_CLAMP;
 
    case STATE_FOG_COLOR:
+      return _NEW_FOG | _NEW_BUFFERS | _NEW_FRAG_CLAMP;
    case STATE_FOG_PARAMS:
       return _NEW_FOG;
 
@@ -688,6 +712,8 @@ _mesa_program_state_flags(const gl_state_index state[STATE_LENGTH])
       switch (state[1]) {
       case STATE_CURRENT_ATTRIB:
          return _NEW_CURRENT_ATTRIB;
+      case STATE_CURRENT_ATTRIB_MAYBE_VP_CLAMPED:
+         return _NEW_CURRENT_ATTRIB | _NEW_LIGHT | _NEW_BUFFERS;
 
       case STATE_NORMAL_SCALE:
          return _NEW_MODELVIEW;
diff --git a/src/mesa/program/prog_statevars.h b/src/mesa/program/prog_statevars.h
index f2407af9c87..9fe8d81b3dd 100644
--- a/src/mesa/program/prog_statevars.h
+++ b/src/mesa/program/prog_statevars.h
@@ -106,6 +106,7 @@ typedef enum gl_state_index_ {
 
    STATE_INTERNAL,		/* Mesa additions */
    STATE_CURRENT_ATTRIB,        /* ctx->Current vertex attrib value */
+   STATE_CURRENT_ATTRIB_MAYBE_VP_CLAMPED,        /* ctx->Current vertex attrib value after passthrough vertex processing */
    STATE_NORMAL_SCALE,
    STATE_TEXRECT_SCALE,
    STATE_FOG_PARAMS_OPTIMIZED,  /* for faster fog calc */
diff --git a/src/mesa/program/programopt.c b/src/mesa/program/programopt.c
index f92881f8337..5ad9571f757 100644
--- a/src/mesa/program/programopt.c
+++ b/src/mesa/program/programopt.c
@@ -238,7 +238,7 @@ _mesa_insert_mvp_code(struct gl_context *ctx, struct gl_vertex_program *vprog)
  * to vertex programs too.
  */
 void
-_mesa_append_fog_code(struct gl_context *ctx, struct gl_fragment_program *fprog)
+_mesa_append_fog_code(struct gl_context *ctx, struct gl_fragment_program *fprog, GLboolean saturate)
 {
    static const gl_state_index fogPStateOpt[STATE_LENGTH]
       = { STATE_INTERNAL, STATE_FOG_PARAMS_OPTIMIZED, 0, 0, 0 };
@@ -290,7 +290,7 @@ _mesa_append_fog_code(struct gl_context *ctx, struct gl_fragment_program *fprog)
          /* change the instruction to write to colorTemp w/ clamping */
          inst->DstReg.File = PROGRAM_TEMPORARY;
          inst->DstReg.Index = colorTemp;
-         inst->SaturateMode = SATURATE_ZERO_ONE;
+         inst->SaturateMode = saturate;
          /* don't break (may be several writes to result.color) */
       }
       inst++;
@@ -300,6 +300,7 @@ _mesa_append_fog_code(struct gl_context *ctx, struct gl_fragment_program *fprog)
    _mesa_init_instructions(inst, 5);
 
    /* emit instructions to compute fog blending factor */
+   /* this is always clamped to [0, 1] regardless of fragment clamping */
    if (fprog->FogOption == GL_LINEAR) {
       /* MAD fogFactorTemp.x, fragment.fogcoord.x, fogPRefOpt.x, fogPRefOpt.y; */
       inst->Opcode = OPCODE_MAD;
diff --git a/src/mesa/program/programopt.h b/src/mesa/program/programopt.h
index ef6f1bd0794..79631aa5843 100644
--- a/src/mesa/program/programopt.h
+++ b/src/mesa/program/programopt.h
@@ -32,7 +32,7 @@ extern void
 _mesa_insert_mvp_code(struct gl_context *ctx, struct gl_vertex_program *vprog);
 
 extern void
-_mesa_append_fog_code(struct gl_context *ctx, struct gl_fragment_program *fprog);
+_mesa_append_fog_code(struct gl_context *ctx, struct gl_fragment_program *fprog, GLboolean saturate);
 
 extern void
 _mesa_count_texture_indirections(struct gl_program *prog);