Merge branch 'new-frag-attribs'

This branch introduces new FRAG_ATTRIB_FACE and FRAG_ATTRIB_PNTC fragment
program inputs for GLSL gl_FrontFacing and gl_PointCoord.  Before, these
attributes were packed with the FOG attribute.  That made things
complicated elsewhere.

12 files changed, 107 insertions, 151 deletions

diff --git a/src/gallium/auxiliary/draw/draw_pipe_wide_point.c b/src/gallium/auxiliary/draw/draw_pipe_wide_point.c
index 014d8c7346..7d76a7dbf3 100644
--- a/src/gallium/auxiliary/draw/draw_pipe_wide_point.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_wide_point.c
@@ -28,6 +28,30 @@
 /* Authors:  Keith Whitwell <keith@tungstengraphics.com>
  */
 
+/**
+ * Notes on wide points and sprite mode:
+ *
+ * In wide point/sprite mode we effectively need to convert each incoming
+ * vertex into four outgoing vertices specifying the corners of a quad.
+ * Since we don't (yet) have geometry shaders, we have to handle this here
+ * in the draw module.
+ *
+ * For sprites, it also means that this is where we have to handle texcoords
+ * for the vertices of the quad.  OpenGL's GL_COORD_REPLACE state specifies
+ * if/how enabled texcoords are automatically generated for sprites.  We pass
+ * that info through gallium in the pipe_rasterizer_state::sprite_coord_mode
+ * array.
+ *
+ * Additionally, GLSL's gl_PointCoord fragment attribute has to be handled
+ * here as well.  This is basically an additional texture/generic attribute
+ * that varies .x from 0 to 1 horizontally across the point and varies .y
+ * vertically from 0 to 1 down the sprite.
+ *
+ * With geometry shaders, the state tracker could create a GS to do
+ * most/all of this.
+ */
+
+
 #include "util/u_math.h"
 #include "util/u_memory.h"
 #include "pipe/p_defines.h"
@@ -52,7 +76,7 @@ struct widepoint_stage {
 
    int psize_slot;
 
-   int point_coord_fs_input;  /**< input for pointcoord (and fog) */
+   int point_coord_fs_input;  /**< input for pointcoord */
 };
 
 
@@ -64,8 +88,6 @@ widepoint_stage( struct draw_stage *stage )
 }
 
 
-
-
 /**
  * Set the vertex texcoords for sprite mode.
  * Coords may be left untouched or set to a right-side-up or upside-down
@@ -89,10 +111,12 @@ static void set_texcoords(const struct widepoint_stage *wide,
    }
 
    if (wide->point_coord_fs_input >= 0) {
-      /* put gl_PointCoord into extra vertex output's zw components */
-      uint k = wide->stage.draw->extra_vp_outputs.slot;
-      v->data[k][2] = tc[0];
-      v->data[k][3] = tc[1];
+      /* put gl_PointCoord into the extra vertex slot */
+      uint slot = wide->stage.draw->extra_vp_outputs.slot;
+      v->data[slot][0] = tc[0];
+      v->data[slot][1] = tc[1];
+      v->data[slot][2] = 0.0F;
+      v->data[slot][3] = 1.0F;
    }
 }
 
@@ -182,10 +206,10 @@ static void widepoint_point( struct draw_stage *stage,
 
 
 static int
-find_fog_input_attrib(struct draw_context *draw)
+find_pntc_input_attrib(struct draw_context *draw)
 {
-   /* Scan the fragment program's input decls to find the fogcoord
-    * attribute.  The z/w components will store the point coord.
+   /* Scan the fragment program's input decls to find the pointcoord
+    * attribute.  The xy components will store the point coord.
     */
    return 0; /* XXX fix this */
 }
@@ -229,8 +253,8 @@ static void widepoint_first_point( struct draw_stage *stage,
       }
       wide->num_texcoords = j;
 
-      /* find fragment shader PointCoord/Fog input */
-      wide->point_coord_fs_input = find_fog_input_attrib(draw);
+      /* find fragment shader PointCoord input */
+      wide->point_coord_fs_input = find_pntc_input_attrib(draw);
 
       /* setup extra vp output (point coord implemented as a texcoord) */
       draw->extra_vp_outputs.semantic_name = TGSI_SEMANTIC_GENERIC;
diff --git a/src/mesa/drivers/dri/i965/brw_wm_fp.c b/src/mesa/drivers/dri/i965/brw_wm_fp.c
index 0eac1bf86a..5dc076a825 100644
--- a/src/mesa/drivers/dri/i965/brw_wm_fp.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_fp.c
@@ -409,14 +409,6 @@ static void emit_interp( struct brw_wm_compile *c,
       }
       break;
    case FRAG_ATTRIB_FOGC:
-      /* The FOGC input is really special.  When a program uses glFogFragCoord,
-       * the results returned are supposed to be (f,0,0,1).  But for Mesa GLSL,
-       * the glFrontFacing and glPointCoord values are also stashed in FOGC.
-       * So, write the interpolated fog value to X, then either 0, 1, or the
-       * stashed values to Y, Z, W.  Note that this means that
-       * glFogFragCoord.yzw can be wrong in those cases!
-       */
-
       /* Interpolate the fog coordinate */
       emit_op(c,
 	      WM_PINTERP,
@@ -426,26 +418,40 @@ static void emit_interp( struct brw_wm_compile *c,
 	      deltas,
 	      get_pixel_w(c));
 
-      /* Move the front facing value into FOGC.y if it's needed. */
-      if (c->fp->program.UsesFrontFacing) {
-	 emit_op(c,
-		 WM_FRONTFACING,
-		 dst_mask(dst, WRITEMASK_Y),
-		 0,
-		 src_undef(),
-		 src_undef(),
-		 src_undef());
-      } else {
-	 emit_op(c,
-		 OPCODE_MOV,
-		 dst_mask(dst, WRITEMASK_Y),
-		 0,
-		 src_swizzle1(interp, SWIZZLE_ZERO),
-		 src_undef(),
-		 src_undef());
-      }
+      emit_op(c,
+	      OPCODE_MOV,
+	      dst_mask(dst, WRITEMASK_YZW),
+	      0,
+	      src_swizzle(interp,
+			  SWIZZLE_ZERO,
+			  SWIZZLE_ZERO,
+			  SWIZZLE_ZERO,
+			  SWIZZLE_ONE),
+	      src_undef(),
+	      src_undef());
+      break;
+
+   case FRAG_ATTRIB_FACE:
+      /* XXX review/test this case */
+      emit_op(c,
+              WM_FRONTFACING,
+              dst_mask(dst, WRITEMASK_X),
+              0,
+              src_undef(),
+              src_undef(),
+              src_undef());
+      break;
+
+   case FRAG_ATTRIB_PNTC:
+      /* XXX review/test this case */
+      emit_op(c,
+	      WM_PINTERP,
+	      dst_mask(dst, WRITEMASK_XY),
+	      0,
+	      interp,
+	      deltas,
+	      get_pixel_w(c));
 
-      /* Should do the PointCoord thing here. */
       emit_op(c,
 	      OPCODE_MOV,
 	      dst_mask(dst, WRITEMASK_ZW),
@@ -458,6 +464,7 @@ static void emit_interp( struct brw_wm_compile *c,
 	      src_undef(),
 	      src_undef());
       break;
+
    default:
       emit_op(c,
 	      WM_PINTERP,
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index e447e4ce23..6a60ad1cee 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -228,7 +228,9 @@ typedef enum
    FRAG_ATTRIB_TEX5 = 9,
    FRAG_ATTRIB_TEX6 = 10,
    FRAG_ATTRIB_TEX7 = 11,
-   FRAG_ATTRIB_VAR0 = 12,  /**< shader varying */
+   FRAG_ATTRIB_FACE = 12,  /**< front/back face */
+   FRAG_ATTRIB_PNTC = 13,  /**< sprite/point coord */
+   FRAG_ATTRIB_VAR0 = 14,  /**< shader varying */
    FRAG_ATTRIB_MAX = (FRAG_ATTRIB_VAR0 + MAX_VARYING)
 } gl_frag_attrib;
 
@@ -240,6 +242,8 @@ typedef enum
 #define FRAG_BIT_COL0  (1 << FRAG_ATTRIB_COL0)
 #define FRAG_BIT_COL1  (1 << FRAG_ATTRIB_COL1)
 #define FRAG_BIT_FOGC  (1 << FRAG_ATTRIB_FOGC)
+#define FRAG_BIT_FACE  (1 << FRAG_ATTRIB_FACE)
+#define FRAG_BIT_PNTC  (1 << FRAG_ATTRIB_PNTC)
 #define FRAG_BIT_TEX0  (1 << FRAG_ATTRIB_TEX0)
 #define FRAG_BIT_TEX1  (1 << FRAG_ATTRIB_TEX1)
 #define FRAG_BIT_TEX2  (1 << FRAG_ATTRIB_TEX2)
@@ -1835,9 +1839,6 @@ struct gl_fragment_program
    struct gl_program Base;   /**< base class */
    GLenum FogOption;
    GLboolean UsesKill;          /**< shader uses KIL instruction */
-   GLboolean UsesPointCoord;    /**< shader uses gl_PointCoord */
-   GLboolean UsesFrontFacing;   /**< shader used gl_FrontFacing */
-   GLboolean UsesFogFragCoord;  /**< shader used gl_FogFragCoord */
 };
 
 
diff --git a/src/mesa/shader/arbprogparse.c b/src/mesa/shader/arbprogparse.c
index 0f530ebb8a..381445c0e8 100644
--- a/src/mesa/shader/arbprogparse.c
+++ b/src/mesa/shader/arbprogparse.c
@@ -3975,13 +3975,6 @@ _mesa_parse_arb_fragment_program(GLcontext* ctx, GLenum target,
    if (program->FogOption)
       program->Base.InputsRead |= FRAG_BIT_FOGC;
 
-   /* XXX: assume that ARB fragment programs don't have access to the
-    * FrontFacing and PointCoord values stuffed into the fog
-    * coordinate in GLSL shaders.
-    */
-   if (program->Base.InputsRead & FRAG_BIT_FOGC)
-      program->UsesFogFragCoord = GL_TRUE;
-      
    if (program->Base.Instructions)
       _mesa_free(program->Base.Instructions);
    program->Base.Instructions = ap.Base.Instructions;
diff --git a/src/mesa/shader/programopt.c b/src/mesa/shader/programopt.c
index ac5fe0f691..f70c75cec8 100644
--- a/src/mesa/shader/programopt.c
+++ b/src/mesa/shader/programopt.c
@@ -396,7 +396,6 @@ _mesa_append_fog_code(GLcontext *ctx, struct gl_fragment_program *fprog)
    fprog->Base.Instructions = newInst;
    fprog->Base.NumInstructions = inst - newInst;
    fprog->Base.InputsRead |= FRAG_BIT_FOGC;
-   fprog->UsesFogFragCoord = GL_TRUE;
    /* XXX do this?  fprog->FogOption = GL_NONE; */
 }
 
diff --git a/src/mesa/shader/slang/slang_builtin.c b/src/mesa/shader/slang/slang_builtin.c
index 5721e9b8f1..9ed8e3ecb3 100644
--- a/src/mesa/shader/slang/slang_builtin.c
+++ b/src/mesa/shader/slang/slang_builtin.c
@@ -752,8 +752,9 @@ static const struct input_info fragInputs[] = {
    { "gl_TexCoord", FRAG_ATTRIB_TEX0, GL_FLOAT_VEC4, SWIZZLE_NOOP },
    /* note: we're packing several quantities into the fogcoord vector */
    { "gl_FogFragCoord", FRAG_ATTRIB_FOGC, GL_FLOAT, SWIZZLE_XXXX },
-   { "gl_FrontFacing", FRAG_ATTRIB_FOGC, GL_BOOL, SWIZZLE_YYYY }, /*XXX*/
-   { "gl_PointCoord", FRAG_ATTRIB_FOGC, GL_FLOAT_VEC2, SWIZZLE_ZWWW },
+   { "gl_FogFragCoord", FRAG_ATTRIB_FOGC, GL_FLOAT, SWIZZLE_XXXX },
+   { "gl_FrontFacing", FRAG_ATTRIB_FACE, GL_FLOAT, SWIZZLE_XXXX },
+   { "gl_PointCoord", FRAG_ATTRIB_PNTC, GL_FLOAT_VEC2, SWIZZLE_XYZW },
    { NULL, 0, SWIZZLE_NOOP }
 };
 
diff --git a/src/mesa/shader/slang/slang_link.c b/src/mesa/shader/slang/slang_link.c
index d1e91d306d..c5c94a65a2 100644
--- a/src/mesa/shader/slang/slang_link.c
+++ b/src/mesa/shader/slang/slang_link.c
@@ -504,20 +504,6 @@ _slang_update_inputs_outputs(struct gl_program *prog)
       for (j = 0; j < numSrc; j++) {
          if (inst->SrcReg[j].File == PROGRAM_INPUT) {
             prog->InputsRead |= 1 << inst->SrcReg[j].Index;
-            if (prog->Target == GL_FRAGMENT_PROGRAM_ARB &&
-                inst->SrcReg[j].Index == FRAG_ATTRIB_FOGC) {
-               /* The fragment shader FOGC input is used for fog,
-                * front-facing and sprite/point coord.
-                */
-               struct gl_fragment_program *fp = fragment_program(prog);
-               const GLint swz = GET_SWZ(inst->SrcReg[j].Swizzle, 0);
-               if (swz == SWIZZLE_X)
-                  fp->UsesFogFragCoord = GL_TRUE;
-               else if (swz == SWIZZLE_Y)
-                  fp->UsesFrontFacing = GL_TRUE;
-               else if (swz == SWIZZLE_Z || swz == SWIZZLE_W)
-                  fp->UsesPointCoord = GL_TRUE;
-            }
          }
          else if (inst->SrcReg[j].File == PROGRAM_ADDRESS) {
             maxAddrReg = MAX2(maxAddrReg, (GLuint) (inst->SrcReg[j].Index + 1));
diff --git a/src/mesa/state_tracker/st_atom_shader.c b/src/mesa/state_tracker/st_atom_shader.c
index 8b3bb5cc03..ee649be885 100644
--- a/src/mesa/state_tracker/st_atom_shader.c
+++ b/src/mesa/state_tracker/st_atom_shader.c
@@ -139,23 +139,6 @@ find_translated_vp(struct st_context *st,
          if (fragInputsRead & (1 << inAttr)) {
             stfp->input_to_slot[inAttr] = numIn;
             numIn++;
-            if (((1 << inAttr) & FRAG_BIT_FOGC)) {
-               /* leave placeholders for the
-                * extra registers we extract from fog */
-               if (stfp->Base.UsesFrontFacing) {
-                  if (!stfp->Base.UsesFogFragCoord)
-                     --stfp->input_to_slot[inAttr];
-                  else
-                     ++numIn;
-               }
-               if (stfp->Base.UsesPointCoord) {
-                  if (!stfp->Base.UsesFrontFacing &&
-                      !stfp->Base.UsesFogFragCoord)
-                     stfp->input_to_slot[inAttr] -= 2;
-                  else
-                     ++numIn;
-               }
-            }
          }
          else {
             stfp->input_to_slot[inAttr] = UNUSED;
diff --git a/src/mesa/state_tracker/st_mesa_to_tgsi.c b/src/mesa/state_tracker/st_mesa_to_tgsi.c
index dd7e40be08..2ab12d3cf3 100644
--- a/src/mesa/state_tracker/st_mesa_to_tgsi.c
+++ b/src/mesa/state_tracker/st_mesa_to_tgsi.c
@@ -112,27 +112,6 @@ map_register_file_index(
 {
    switch( file ) {
    case TGSI_FILE_INPUT:
-      if (procType == TGSI_PROCESSOR_FRAGMENT &&
-          index == FRAG_ATTRIB_FOGC) {
-         if (GET_SWZ(*swizzle, 0) == SWIZZLE_X) {
-            /* do nothing we're, ok */
-         } else if (GET_SWZ(*swizzle, 0) == SWIZZLE_Y) {
-            /* replace the swizzle with xxxx */
-            *swizzle = MAKE_SWIZZLE4(SWIZZLE_X,
-                                     SWIZZLE_X,
-                                     SWIZZLE_X,
-                                     SWIZZLE_X);
-            /* register after fog */
-            return inputMapping[index] + 1;
-         } else {
-            *swizzle = MAKE_SWIZZLE4(SWIZZLE_Z,
-                                     SWIZZLE_W,
-                                     SWIZZLE_Z,
-                                     SWIZZLE_W);
-            /* register after frontface */
-            return inputMapping[index] + 2;
-         }
-      }
       /* inputs are mapped according to the user-defined map */
       return inputMapping[index];
 
diff --git a/src/mesa/state_tracker/st_program.c b/src/mesa/state_tracker/st_program.c
index 806e0ca8f6..d2da20ae42 100644
--- a/src/mesa/state_tracker/st_program.c
+++ b/src/mesa/state_tracker/st_program.c
@@ -458,34 +458,20 @@ st_translate_fragment_program(struct st_context *st,
             stfp->input_semantic_index[slot] = 1;
             interpMode[slot] = TGSI_INTERPOLATE_LINEAR;
             break;
-         case FRAG_ATTRIB_FOGC: {
-            int extra_decls = 0;
-            if (stfp->Base.UsesFogFragCoord) {
-               stfp->input_semantic_name[slot] = TGSI_SEMANTIC_FOG;
-               stfp->input_semantic_index[slot] = 0;
-               interpMode[slot] = TGSI_INTERPOLATE_PERSPECTIVE;
-               input_flags[slot] = stfp->Base.Base.InputFlags[attr];
-               ++extra_decls;
-	    }
-            if (stfp->Base.UsesFrontFacing) {
-               GLint idx = slot + extra_decls;
-               stfp->input_semantic_name[idx] = TGSI_SEMANTIC_FACE;
-               stfp->input_semantic_index[idx] = 0;
-               interpMode[idx] = TGSI_INTERPOLATE_CONSTANT;
-               input_flags[idx] = stfp->Base.Base.InputFlags[attr];
-               ++extra_decls;
-            }
-            if (stfp->Base.UsesPointCoord) {
-               GLint idx = slot + extra_decls;
-               stfp->input_semantic_name[idx] = TGSI_SEMANTIC_GENERIC;
-               stfp->input_semantic_index[idx] = num_generic++;
-               interpMode[idx] = TGSI_INTERPOLATE_PERSPECTIVE;
-               input_flags[idx] = stfp->Base.Base.InputFlags[attr];
-               ++extra_decls;
-            }
-            fs_num_inputs += extra_decls - 1;
-            continue;
-         }
+         case FRAG_ATTRIB_FOGC:
+            stfp->input_semantic_name[slot] = TGSI_SEMANTIC_FOG;
+            stfp->input_semantic_index[slot] = 0;
+            interpMode[slot] = TGSI_INTERPOLATE_PERSPECTIVE;
+            break;
+         case FRAG_ATTRIB_FACE:
+            stfp->input_semantic_name[slot] = TGSI_SEMANTIC_FACE;
+            stfp->input_semantic_index[slot] = num_generic++;
+            interpMode[slot] = TGSI_INTERPOLATE_CONSTANT;
+            break;
+         case FRAG_ATTRIB_PNTC:
+            stfp->input_semantic_name[slot] = TGSI_SEMANTIC_GENERIC;
+            stfp->input_semantic_index[slot] = num_generic++;
+            interpMode[slot] = TGSI_INTERPOLATE_PERSPECTIVE;
             break;
          case FRAG_ATTRIB_TEX0:
          case FRAG_ATTRIB_TEX1:
diff --git a/src/mesa/swrast/s_fragprog.c b/src/mesa/swrast/s_fragprog.c
index b71fb9eae9..613a91b0ec 100644
--- a/src/mesa/swrast/s_fragprog.c
+++ b/src/mesa/swrast/s_fragprog.c
@@ -157,9 +157,8 @@ init_machine(GLcontext *ctx, struct gl_program_machine *machine,
 
    /* if running a GLSL program (not ARB_fragment_program) */
    if (ctx->Shader.CurrentProgram) {
-      /* Store front/back facing value in register FOGC.Y */
-      machine->Attribs[FRAG_ATTRIB_FOGC][col][1] = 1.0 - span->facing;
-      /* Note FOGC.ZW is gl_PointCoord if drawing a sprite */
+      /* Store front/back facing value */
+      machine->Attribs[FRAG_ATTRIB_FACE][col][0] = 1.0 - span->facing;
    }
 
    machine->CurElement = col;
diff --git a/src/mesa/swrast/s_points.c b/src/mesa/swrast/s_points.c
index 0a3ad97a71..50ec2063a5 100644
--- a/src/mesa/swrast/s_points.c
+++ b/src/mesa/swrast/s_points.c
@@ -139,9 +139,10 @@ sprite_point(GLcontext *ctx, const SWvertex *vert)
       }
 
       ATTRIB_LOOP_BEGIN
-         if (attr >= FRAG_ATTRIB_TEX0 && attr < FRAG_ATTRIB_VAR0) {
+         if (attr >= FRAG_ATTRIB_TEX0 && attr <= FRAG_ATTRIB_TEX7) {
+            /* a texcoord attribute */
             const GLuint u = attr - FRAG_ATTRIB_TEX0;
-            /* a texcoord */
+            ASSERT(u < Elements(ctx->Point.CoordReplace));
             if (ctx->Point.CoordReplace[u]) {
                tCoords[numTcoords++] = attr;
 
@@ -170,15 +171,15 @@ sprite_point(GLcontext *ctx, const SWvertex *vert)
                continue;
             }
          }
-         else if (attr == FRAG_ATTRIB_FOGC) {
-            /* GLSL gl_PointCoord is stored in fog.zw */
-            span.attrStart[FRAG_ATTRIB_FOGC][2] = 0.0;
-            span.attrStart[FRAG_ATTRIB_FOGC][3] = 0.0; /* t0 set below */
-            span.attrStepX[FRAG_ATTRIB_FOGC][2] = dsdx;
-            span.attrStepX[FRAG_ATTRIB_FOGC][3] = 0.0;
-            span.attrStepY[FRAG_ATTRIB_FOGC][2] = 0.0;
-            span.attrStepY[FRAG_ATTRIB_FOGC][3] = dtdy;
-            tCoords[numTcoords++] = FRAG_ATTRIB_FOGC;
+         else if (attr == FRAG_ATTRIB_PNTC) {
+            /* GLSL gl_PointCoord.xy (.zw undefined) */
+            span.attrStart[FRAG_ATTRIB_PNTC][0] = 0.0;
+            span.attrStart[FRAG_ATTRIB_PNTC][1] = 0.0; /* t0 set below */
+            span.attrStepX[FRAG_ATTRIB_PNTC][0] = dsdx;
+            span.attrStepX[FRAG_ATTRIB_PNTC][1] = 0.0;
+            span.attrStepY[FRAG_ATTRIB_PNTC][0] = 0.0;
+            span.attrStepY[FRAG_ATTRIB_PNTC][1] = dtdy;
+            tCoords[numTcoords++] = FRAG_ATTRIB_PNTC;
             continue;
          }
          /* use vertex's texcoord/attrib */
@@ -221,10 +222,7 @@ sprite_point(GLcontext *ctx, const SWvertex *vert)
          GLuint i;
          /* setup texcoord T for this row */
          for (i = 0; i < numTcoords; i++) {
-            if (tCoords[i] == FRAG_ATTRIB_FOGC)
-               span.attrStart[FRAG_ATTRIB_FOGC][3] = tcoord;
-            else
-               span.attrStart[tCoords[i]][1] = tcoord;
+            span.attrStart[tCoords[i]][1] = tcoord;
          }
 
          /* these might get changed by span clipping */