commit 1b3a83bd57065aa015d5251f44bea0b710838581
Author: chr <chr@ECHELON.(none)>
Date:   Sat May 16 16:39:38 2009 +0200

    - Make TXP do what it's supposed to (centroid not yet honored, could
      store interpolation mode in some per register flag maybe).
    
    - FIX: don't set perspect_load = FALSE if we encounter a centroid
      attribute, instead make perspect/centroid_load counters.

diff --git a/src/gallium/drivers/nv50/nv50_program.c b/src/gallium/drivers/nv50/nv50_program.c
index 3a00c90..3116735 100644
--- a/src/gallium/drivers/nv50/nv50_program.c
+++ b/src/gallium/drivers/nv50/nv50_program.c
@@ -1497,14 +1497,33 @@ nv50_program_tx_insn(struct nv50_pc *pc, const union tgsi_full_token *tok)
 		}
 		break;
 	case TGSI_OPCODE_TEX:
-	case TGSI_OPCODE_TXP: /* XXX: TXP should use w-component as iv on interp */
+	case TGSI_OPCODE_TXP:
 	{
 		struct nv50_reg *t[4];
 		struct nv50_program_exec *e;
 
 		alloc_temp4(pc, t, 0);
-		emit_mov(pc, t[0], src[0][0]);
-		emit_mov(pc, t[1], src[0][1]);
+
+		if (inst->Instruction.Opcode == TGSI_OPCODE_TXP) {
+			if (src[0][0]->type == P_TEMP && src[0][0]->rhw != -1) {
+				/* XXX: centroid is not honored here */
+				t[1]->rhw = src[0][3]->rhw;
+				emit_interp(pc, t[1], NULL, INTERP_LINEAR);
+				emit_flop(pc, 0, t[1], t[1]);
+				t[0]->rhw = src[0][0]->rhw;
+				t[1]->rhw = src[0][1]->rhw;
+				emit_interp(pc, t[0], t[1], INTERP_PERSPECTIVE);
+				emit_interp(pc, t[1], t[1], INTERP_PERSPECTIVE);
+			} else {
+				emit_mov(pc, t[1], src[0][3]);
+				emit_flop(pc, 0, t[1], t[1]);
+				emit_mul(pc, t[0], src[0][0], t[1]);
+				emit_mul(pc, t[1], src[0][1], t[1]);
+			}
+		} else {
+			emit_mov(pc, t[0], src[0][0]);
+			emit_mov(pc, t[1], src[0][1]);
+		}
 
 		e = exec(pc);
 		e->inst[0] = 0xf6400000;
@@ -1514,6 +1533,7 @@ nv50_program_tx_insn(struct nv50_pc *pc, const union tgsi_full_token *tok)
 		set_dst(pc, t[0], e);
 		emit(pc, e);
 
+		/* XXX: without these MOVs, it can happen that TEX has no effect */
 		if (mask & (1 << 0)) emit_mov(pc, dst[0], t[0]);
 		if (mask & (1 << 1)) emit_mov(pc, dst[1], t[1]);
 		if (mask & (1 << 2)) emit_mov(pc, dst[2], t[2]);
@@ -1636,8 +1656,8 @@ nv50_program_tx_prep(struct nv50_pc *pc)
 	unsigned fcol, bcol, fcrd, depr;
 
 	/* record interpolation mode from declaration */
-	boolean centroid_load = FALSE;
-	boolean perspect_load = FALSE;
+	unsigned centroid_load = 0;
+	unsigned perspect_load = 0;
 	unsigned interp_mode[32];
 
 	/* track register usage for temps and attrs */
@@ -1721,38 +1741,45 @@ nv50_program_tx_prep(struct nv50_pc *pc)
 					break;
 				case TGSI_INTERPOLATE_PERSPECTIVE:
 					mode = INTERP_PERSPECTIVE;
-					perspect_load = TRUE;
+					if (!d->Declaration.Centroid)
+						perspect_load++;
 					break;
 				default:
 					mode = INTERP_LINEAR;
 					break;
 				}
 
+				if (d->Declaration.Centroid) {
+					mode |= INTERP_CENTROID;
+					centroid_load++;
+				}
+				
 				if (d->Declaration.Semantic) {
 					switch (d->Semantic.SemanticName) {
 					case TGSI_SEMANTIC_POSITION:
 						fcrd = first;
 						break;
+					/* XXX: FLAT and LINEAR don't seem to behave correctly: */
 					case TGSI_SEMANTIC_COLOR:
 						fcol = first;
-						mode = INTERP_PERSPECTIVE;
-						perspect_load = TRUE;
+						if (!(mode & INTERP_PERSPECTIVE)) {
+							mode &= INTERP_CENTROID;
+							mode |= INTERP_PERSPECTIVE;
+							perspect_load++;
+						}
 						break;
 					case TGSI_SEMANTIC_BCOLOR:
 						bcol = first;
-						mode = INTERP_PERSPECTIVE;
-						perspect_load = TRUE;
+						if (!(mode & INTERP_PERSPECTIVE)) {
+							mode &= INTERP_CENTROID;
+							mode |= INTERP_PERSPECTIVE;
+							perspect_load++;
+						}
 						break;
 					default:
 						break;
 					}
 				}
-
-				if (d->Declaration.Centroid) {
-					mode |= INTERP_CENTROID;
-					centroid_load = TRUE;
-					perspect_load = FALSE;
-				}
 				
 				assert(last < 32);
 				for (i = first; i <= last; i++)