--- /dev/null
+/*
+ * $XConsortium: cfbrrop.c,v 1.8 94/04/17 20:28:59 dpw Exp $
+ *
+Copyright (c) 1989 X Consortium
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of the X Consortium shall not be
+used in advertising or otherwise to promote the sale, use or other dealings
+in this Software without prior written authorization from the X Consortium.
+ *
+ * Author: Keith Packard, MIT X Consortium
+ */
+
+/* cfb reduced rasterop computations */
+
+#include "X.h"
+#include "Xmd.h"
+#include "Xproto.h"
+#include "cfb.h"
+#include "cfbmskbits.h"
+
+/* A description:
+ *
+ * There are four possible operations on each bit in the destination word,
+ *
+ * 1 2 3 4
+ *
+ * 0 0 0 1 1
+ * 1 0 1 0 1
+ *
+ * On examination of the reduced rop equation (dst = (dst & and) ^ xor),
+ * these four fall to reduced rops as follows:
+ *
+ * and 0 1 1 0
+ * xor 0 0 1 1
+ *
+ * or, (if 'and' is expensive) (dst = (dst | or) ^ xor)
+ *
+ * or 1 0 0 1
+ * xor 1 0 1 0
+ *
+ * The trouble with using this later equation is that trivial
+ * rasterop reduction is more difficult; some common rasterops
+ * use complicated expressions of xor/and instead of the simple
+ * ones while other common rasterops are not made any simpler:
+ *
+ * GXcopy: *dst = ~xor instead of *dst = xor
+ * GXand: *dst = *dst & ~or instead of *dst = *dst & and
+ * GXor: *dst = *dst | or instead of *dst = *dst | xor
+ * GXxor: *dst = *dst ^ xor instead of *dst = *dst ^ xor
+ *
+ * If you're really set on using this second mechanism, the changes
+ * are pretty simple.
+ *
+ * All that remains is to provide a mechanism for computing and/xor values
+ * based on the raster op and foreground value.
+ *
+ * The 16 rops fall as follows, with the associated reduced
+ * rop and/xor and or/xor values. The values in parenthesis following the
+ * reduced values gives an equation using the source value for
+ * the reduced value, and is one of {0, src, ~src, 1} as appropriate.
+ *
+ * clear and andReverse copy
+ * src 0 1 0 1 0 1 0 1
+ * dst 0 0 0 0 0 0 0 0 1 0 0 1
+ * 1 0 0 1 0 1 1 0 0 1 0 1
+ *
+ * and 0 0 (0) 0 1 (src) 0 1 (src) 0 0 (0)
+ * xor 0 0 (0) 0 0 (0) 0 1 (src) 0 1 (src)
+ *
+ * or 1 1 (1) 1 0 (~src) 1 0 (~src) 1 1 (1)
+ * xor 1 1 (1) 1 0 (~src) 1 1 (1) 1 0 (~src)
+ *
+ * andInverted noop xor or
+ * src 0 1 0 1 0 1 0 1
+ * dst 0 0 0 0 0 0 0 0 1 0 0 1
+ * 1 1 0 1 1 1 1 1 0 1 1 1
+ *
+ * and 1 0 (~src) 1 1 (1) 1 1 (1) 1 0 (~src)
+ * xor 0 0 (0) 0 0 (0) 0 1 (src) 0 1 (src)
+ *
+ * or 0 1 (src) 0 0 (0) 0 0 (0) 0 1 (src)
+ * xor 0 1 (src) 0 0 (0) 0 1 (src) 0 0 (0)
+ *
+ * nor equiv invert orReverse
+ * src 0 1 0 1 0 1 0 1
+ * dst 0 1 0 0 1 0 0 1 1 0 1 1
+ * 1 0 0 1 0 1 1 0 0 1 0 1
+ *
+ * and 1 0 (~src) 1 1 (1) 1 1 (1) 1 0 (~src)
+ * xor 1 0 (~src) 1 0 (~src) 1 1 (1) 1 1 (1)
+ *
+ * or 0 1 (src) 0 0 (0) 0 0 (0) 0 1 (src)
+ * xor 1 1 (1) 1 0 (~src) 1 1 (1) 1 0 (~src)
+ *
+ * copyInverted orInverted nand set
+ * src 0 1 0 1 0 1 0 1
+ * dst 0 1 0 0 1 0 0 1 1 0 1 1
+ * 1 1 0 1 1 1 1 1 0 1 1 1
+ *
+ * and 0 0 (0) 0 1 (src) 0 1 (src) 0 0 (0)
+ * xor 1 0 (~src) 1 0 (~src) 1 1 (1) 1 1 (1)
+ *
+ * or 1 1 (1) 1 0 (~src) 1 0 (~src) 1 1 (1)
+ * xor 0 1 (src) 0 0 (0) 0 1 (src) 0 0 (0)
+ */
+
+int
+cfbReduceRasterOp (rop, fg, pm, andp, xorp)
+ int rop;
+ unsigned long fg, pm;
+ unsigned long *andp, *xorp;
+{
+ unsigned long and, xor;
+ int rrop;
+
+ fg = PFILL (fg);
+ pm = PFILL (pm);
+ switch (rop)
+ {
+ case GXclear:
+ and = 0;
+ xor = 0;
+ break;
+ case GXand:
+ and = fg;
+ xor = 0;
+ break;
+ case GXandReverse:
+ and = fg;
+ xor = fg;
+ break;
+ case GXcopy:
+ and = 0;
+ xor = fg;
+ break;
+ case GXandInverted:
+ and = ~fg;
+ xor = 0;
+ break;
+ case GXnoop:
+ and = ~0;
+ xor = 0;
+ break;
+ case GXxor:
+ and = ~0;
+ xor = fg;
+ break;
+ case GXor:
+ and = ~fg;
+ xor = fg;
+ break;
+ case GXnor:
+ and = ~fg;
+ xor = ~fg;
+ break;
+ case GXequiv:
+ and = ~0;
+ xor = ~fg;
+ break;
+ case GXinvert:
+ and = ~0;
+ xor = ~0;
+ break;
+ case GXorReverse:
+ and = ~fg;
+ xor = ~0;
+ break;
+ case GXcopyInverted:
+ and = 0;
+ xor = ~fg;
+ break;
+ case GXorInverted:
+ and = fg;
+ xor = ~fg;
+ break;
+ case GXnand:
+ and = fg;
+ xor = ~0;
+ break;
+ case GXset:
+ and = 0;
+ xor = ~0;
+ break;
+ }
+ and |= ~pm;
+ xor &= pm;
+ *andp = and;
+ *xorp = xor;
+ /* check for some special cases to reduce computation */
+ if (and == 0)
+ rrop = GXcopy;
+ /* nothing checks for GXnoop
+ else if (and == ~0 && xor == 0)
+ rrop = GXnoop;
+ */
+ else if (and == ~0)
+ rrop = GXxor;
+ else if (xor == 0)
+ rrop = GXand;
+ else if ( (and ^ xor) == ~0) /* fix XBUG 6541 */
+ rrop = GXor;
+ else
+ rrop = GXset; /* rop not reduced */
+ return rrop;
+}
projects / rdpsrv / blobdiff