Fix problems in render fb implementation found by rendercheck:

- fbCombineSaturate was pointed at fbCombineDisjointOver, instead of
    fbCombineDisjointOverReverse as it should. Instead, point
    fbCombineDisjointOverReverse at fbCombineSaturate (which is likely to
    be faster).
- fix previously-unused fbCombineSaturate implementation.
- fbCombineMaskAlphaC was just a copy of fbCombineMaskValueC. Make it do
    what it's supposed to (return a cs.alpha).
- fbCombineAtopC didn't invert the source alpha value.
- fix copy'n'paste errors in fbCombine(Dis/Con)jointGeneralC, also source
    alpha wasn't treated in a component fashion.
- fbCompositeSrc_8888* didn't handle when the source lacks an alpha
    channel. Rather than adding that and possilby slowing down the (normal)
    alpha case, don't let x8r8g8b8/x8b8g8r8 Pictures be used in
    fbCompositeSrc_8888* because Over with one of these is just Src.

3 files changed, 65 insertions, 84 deletions

diff --git a/fb/fbcompose.c b/fb/fbcompose.c
index f650c972a..e0be7b155 100644
--- a/fb/fbcompose.c
+++ b/fb/fbcompose.c
@@ -1,5 +1,5 @@
 /*
- * $XdotOrg: xc/programs/Xserver/fb/fbcompose.c,v 1.18 2003/12/04 17:15:12 tsi Exp $
+ * $XdotOrg: xc/programs/Xserver/fb/fbcompose.c,v 1.2 2004/04/23 19:05:14 eich Exp $
  * $XFree86: xc/programs/Xserver/fb/fbcompose.c,v 1.17tsi Exp $
  *
  * Copyright © 2000 Keith Packard, member of The XFree86 Project, Inc.
@@ -191,15 +191,15 @@ fbCombineMaskAlphaC (FbCompositeOperand   *src,
     a = (*msk->fetcha) (msk);
     if (!a)
 	return 0;
-    
-    x = (*src->fetcha) (src);
-    if (a == 0xffffffff)
-	return x;
-    
-    m = FbInC(x,0,a,t);
-    n = FbInC(x,8,a,t);
-    o = FbInC(x,16,a,t);
-    p = FbInC(x,24,a,t);
+
+    x = (*src->fetch) (src) >> 24;
+    if (x == 0xff)
+	return a;
+
+    m = FbInU(a,0,x,t);
+    n = FbInU(a,8,x,t);
+    o = FbInU(a,16,x,t);
+    p = FbInU(a,24,x,t);
     return m|n|o|p;
 }
 
@@ -608,7 +608,7 @@ fbCombineAtopC (FbCompositeOperand   *src,
     cs = fbCombineMaskC (src, msk);
     d = (*dst->fetch) (dst);
     s = cs.value;
-    ad = cs.alpha;
+    ad = ~cs.alpha;
     as = d >> 24;
     m = FbGen(s,d,0,as,FbGet8(ad,0),t,u,v);
     n = FbGen(s,d,8,as,FbGet8(ad,8),t,u,v);
@@ -698,10 +698,10 @@ fbCombineXorC (FbCompositeOperand    *src,
     s = cs.value;
     ad = ~cs.alpha;
     as = ~d >> 24;
-    m = FbGen(s,d,0,as,ad,t,u,v);
-    n = FbGen(s,d,8,as,ad,t,u,v);
-    o = FbGen(s,d,16,as,ad,t,u,v);
-    p = FbGen(s,d,24,as,ad,t,u,v);
+    m = FbGen(s,d,0,as,FbGet8(ad,0),t,u,v);
+    n = FbGen(s,d,8,as,FbGet8(ad,8),t,u,v);
+    o = FbGen(s,d,16,as,FbGet8(ad,16),t,u,v);
+    p = FbGen(s,d,24,as,FbGet8(ad,24),t,u,v);
     (*dst->store) (dst, m|n|o|p);
 }
 
@@ -763,10 +763,9 @@ fbCombineSaturateU (FbCompositeOperand   *src,
 		    FbCompositeOperand   *dst)
 {
     CARD32  s = fbCombineMaskU (src, msk), d;
-#if 0
     CARD16  sa, da;
     CARD16  ad, as;
-    CARD16  t;
+    CARD16  t, u, v;
     CARD32  m,n,o,p;
     
     d = (*dst->fetch) (dst);
@@ -789,16 +788,6 @@ fbCombineSaturateU (FbCompositeOperand   *src,
 	p = FbGen(s,d,24,as,ad,t,u,v);
     }
     (*dst->store) (dst, m|n|o|p);
-#else
-    if ((s >> 24) == 0xff)
-	(*dst->store) (dst, s);
-    else
-    {
-	d = (*dst->fetch) (dst);
-	if ((s >> 24) > (d >> 24))
-	    (*dst->store) (dst, s);
-    }
-#endif
 }
 
 void
@@ -831,7 +820,7 @@ fbCombineSaturateC (FbCompositeOperand   *src,
     else
 	n = FbGen (s, d, 8, (da << 8) / sg, 0xff, t, u, v);
     
-    if (sr < da)
+    if (sr <= da)
 	o = FbAdd(s,d,16,t);
     else
 	o = FbGen (s, d, 16, (da << 8) / sr, 0xff, t, u, v);
@@ -972,8 +961,8 @@ fbCombineDisjointGeneralC (FbCompositeOperand   *src,
     FbCompSrc	cs;
     CARD32  s, d;
     CARD32  m,n,o,p;
-    CARD32  Fa;
-    CARD16  Fb, t, u, v;
+    CARD32  Fa, Fb;
+    CARD16  t, u, v;
     CARD32  sa;
     CARD8   da;
 
@@ -996,10 +985,10 @@ fbCombineDisjointGeneralC (FbCompositeOperand   *src,
 	Fa = m|n|o|p;
 	break;
     case CombineAIn:
-	m = fbCombineDisjointOutPart ((CARD8) (sa >> 0), da);
-	n = fbCombineDisjointOutPart ((CARD8) (sa >> 8), da) << 8;
-	o = fbCombineDisjointOutPart ((CARD8) (sa >> 16), da) << 16;
-	p = fbCombineDisjointOutPart ((CARD8) (sa >> 24), da) << 24;
+	m = fbCombineDisjointInPart ((CARD8) (sa >> 0), da);
+	n = fbCombineDisjointInPart ((CARD8) (sa >> 8), da) << 8;
+	o = fbCombineDisjointInPart ((CARD8) (sa >> 16), da) << 16;
+	p = fbCombineDisjointInPart ((CARD8) (sa >> 24), da) << 24;
 	Fa = m|n|o|p;
 	break;
     case CombineA:
@@ -1012,19 +1001,27 @@ fbCombineDisjointGeneralC (FbCompositeOperand   *src,
 	Fb = 0;
 	break;
     case CombineBOut:
-	Fb = fbCombineDisjointOutPart (da, sa);
+	m = fbCombineDisjointOutPart (da, (CARD8) (sa >> 0));
+	n = fbCombineDisjointOutPart (da, (CARD8) (sa >> 8)) << 8;
+	o = fbCombineDisjointOutPart (da, (CARD8) (sa >> 16)) << 16;
+	p = fbCombineDisjointOutPart (da, (CARD8) (sa >> 24)) << 24;
+	Fb = m|n|o|p;
 	break;
     case CombineBIn:
-	Fb = fbCombineDisjointInPart (da, sa);
+	m = fbCombineDisjointInPart (da, (CARD8) (sa >> 0));
+	n = fbCombineDisjointInPart (da, (CARD8) (sa >> 8)) << 8;
+	o = fbCombineDisjointInPart (da, (CARD8) (sa >> 16)) << 16;
+	p = fbCombineDisjointInPart (da, (CARD8) (sa >> 24)) << 24;
+	Fb = m|n|o|p;
 	break;
     case CombineB:
-	Fb = 0xff;
+	Fb = 0xffffffff;
 	break;
     }
-    m = FbGen (s,d,0,FbGet8(Fa,0),Fb,t,u,v);
-    n = FbGen (s,d,8,FbGet8(Fa,8),Fb,t,u,v);
-    o = FbGen (s,d,16,FbGet8(Fa,16),Fb,t,u,v);
-    p = FbGen (s,d,24,FbGet8(Fa,24),Fb,t,u,v);
+    m = FbGen (s,d,0,FbGet8(Fa,0),FbGet8(Fb,0),t,u,v);
+    n = FbGen (s,d,8,FbGet8(Fa,8),FbGet8(Fb,8),t,u,v);
+    o = FbGen (s,d,16,FbGet8(Fa,16),FbGet8(Fb,16),t,u,v);
+    p = FbGen (s,d,24,FbGet8(Fa,24),FbGet8(Fb,24),t,u,v);
     s = m|n|o|p;
     (*dst->store) (dst, s);
 }
@@ -1065,21 +1062,6 @@ fbCombineDisjointOverC (FbCompositeOperand   *src,
     fbCombineDisjointGeneralC (src, msk, dst, CombineAOver);
 }
 
-void
-fbCombineDisjointOverReverseU (FbCompositeOperand    *src,
-			       FbCompositeOperand    *msk,
-			       FbCompositeOperand    *dst)
-{
-    fbCombineDisjointGeneralU (src, msk, dst, CombineBOver);
-}
-
-void
-fbCombineDisjointOverReverseC (FbCompositeOperand    *src,
-			       FbCompositeOperand    *msk,
-			       FbCompositeOperand    *dst)
-{
-    fbCombineDisjointGeneralC (src, msk, dst, CombineBOver);
-}
 
 void
 fbCombineDisjointInU (FbCompositeOperand	    *src,
@@ -1281,8 +1263,8 @@ fbCombineConjointGeneralC (FbCompositeOperand   *src,
     FbCompSrc	cs;
     CARD32  s, d;
     CARD32  m,n,o,p;
-    CARD32  Fa;
-    CARD16  Fb, t, u, v;
+    CARD32  Fa, Fb;
+    CARD16  t, u, v;
     CARD32  sa;
     CARD8   da;
 
@@ -1305,10 +1287,10 @@ fbCombineConjointGeneralC (FbCompositeOperand   *src,
 	Fa = m|n|o|p;
 	break;
     case CombineAIn:
-	m = fbCombineConjointOutPart ((CARD8) (sa >> 0), da);
-	n = fbCombineConjointOutPart ((CARD8) (sa >> 8), da) << 8;
-	o = fbCombineConjointOutPart ((CARD8) (sa >> 16), da) << 16;
-	p = fbCombineConjointOutPart ((CARD8) (sa >> 24), da) << 24;
+	m = fbCombineConjointInPart ((CARD8) (sa >> 0), da);
+	n = fbCombineConjointInPart ((CARD8) (sa >> 8), da) << 8;
+	o = fbCombineConjointInPart ((CARD8) (sa >> 16), da) << 16;
+	p = fbCombineConjointInPart ((CARD8) (sa >> 24), da) << 24;
 	Fa = m|n|o|p;
 	break;
     case CombineA:
@@ -1321,19 +1303,27 @@ fbCombineConjointGeneralC (FbCompositeOperand   *src,
 	Fb = 0;
 	break;
     case CombineBOut:
-	Fb = fbCombineConjointOutPart (da, sa);
+	m = fbCombineConjointOutPart (da, (CARD8) (sa >> 0));
+	n = fbCombineConjointOutPart (da, (CARD8) (sa >> 8)) << 8;
+	o = fbCombineConjointOutPart (da, (CARD8) (sa >> 16)) << 16;
+	p = fbCombineConjointOutPart (da, (CARD8) (sa >> 24)) << 24;
+	Fb = m|n|o|p;
 	break;
     case CombineBIn:
-	Fb = fbCombineConjointInPart (da, sa);
+	m = fbCombineConjointInPart (da, (CARD8) (sa >> 0));
+	n = fbCombineConjointInPart (da, (CARD8) (sa >> 8)) << 8;
+	o = fbCombineConjointInPart (da, (CARD8) (sa >> 16)) << 16;
+	p = fbCombineConjointInPart (da, (CARD8) (sa >> 24)) << 24;
+	Fb = m|n|o|p;
 	break;
     case CombineB:
-	Fb = 0xff;
+	Fb = 0xffffffff;
 	break;
     }
-    m = FbGen (s,d,0,FbGet8(Fa,0),Fb,t,u,v);
-    n = FbGen (s,d,8,FbGet8(Fa,8),Fb,t,u,v);
-    o = FbGen (s,d,16,FbGet8(Fa,16),Fb,t,u,v);
-    p = FbGen (s,d,24,FbGet8(Fa,24),Fb,t,u,v);
+    m = FbGen (s,d,0,FbGet8(Fa,0),FbGet8(Fb,0),t,u,v);
+    n = FbGen (s,d,8,FbGet8(Fa,8),FbGet8(Fb,8),t,u,v);
+    o = FbGen (s,d,16,FbGet8(Fa,16),FbGet8(Fb,16),t,u,v);
+    p = FbGen (s,d,24,FbGet8(Fa,24),FbGet8(Fb,24),t,u,v);
     s = m|n|o|p;
     (*dst->store) (dst, s);
 }
@@ -1519,14 +1509,14 @@ FbCombineFunc	fbCombineFuncU[] = {
     fbCombineAtopReverseU,
     fbCombineXorU,
     fbCombineAddU,
-    fbCombineDisjointOverU, /* Saturate */
+    fbCombineSaturateU,
     0,
     0,
     fbCombineClear,
     fbCombineSrcU,
     fbCombineDst,
     fbCombineDisjointOverU,
-    fbCombineDisjointOverReverseU,
+    fbCombineSaturateU, /* DisjointOverReverse */
     fbCombineDisjointInU,
     fbCombineDisjointInReverseU,
     fbCombineDisjointOutU,
@@ -1566,14 +1556,14 @@ FbCombineFunc	fbCombineFuncC[] = {
     fbCombineAtopReverseC,
     fbCombineXorC,
     fbCombineAddC,
-    fbCombineDisjointOverC, /* Saturate */
+    fbCombineSaturateC,
     0,
     0,
     fbCombineClear,	    /* 0x10 */
     fbCombineSrcC,
     fbCombineDst,
     fbCombineDisjointOverC,
-    fbCombineDisjointOverReverseC,
+    fbCombineSaturateC, /* DisjointOverReverse */
     fbCombineDisjointInC,
     fbCombineDisjointInReverseC,
     fbCombineDisjointOutC,
diff --git a/fb/fbpict.c b/fb/fbpict.c
index 533f08d01..3f989bc56 100644
--- a/fb/fbpict.c
+++ b/fb/fbpict.c
@@ -1001,7 +1001,6 @@ fbComposite (CARD8      op,
 	{
 	    switch (pSrc->format) {
 	    case PICT_a8r8g8b8:
-	    case PICT_x8r8g8b8:
 		switch (pDst->format) {
 		case PICT_a8r8g8b8:
 		case PICT_x8r8g8b8:
@@ -1016,7 +1015,6 @@ fbComposite (CARD8      op,
 		}
 		break;
 	    case PICT_a8b8g8r8:
-	    case PICT_x8b8g8r8:
 		switch (pDst->format) {
 		case PICT_a8b8g8r8:
 		case PICT_x8b8g8r8:
diff --git a/fb/fbpict.h b/fb/fbpict.h
index 9ecc7a909..927434950 100644
--- a/fb/fbpict.h
+++ b/fb/fbpict.h
@@ -333,15 +333,8 @@ fbCombineDisjointOverC (FbCompositeOperand   *src,
 			FbCompositeOperand   *msk,
 			FbCompositeOperand   *dst);
 
-void
-fbCombineDisjointOverReverseU (FbCompositeOperand    *src,
-			       FbCompositeOperand    *msk,
-			       FbCompositeOperand    *dst);
-
-void
-fbCombineDisjointOverReverseC (FbCompositeOperand    *src,
-			       FbCompositeOperand    *msk,
-			       FbCompositeOperand    *dst);
+#define fbCombineDisjointOverReverseU fbCombineSaturateU
+#define fbCombineDisjointOverReverseC fbCombineSaturateC
 
 void
 fbCombineDisjointInU (FbCompositeOperand	    *src,