hw/display/sm501: Implement more 2D raster operations

Add simple implementation for two raster operations that are used by
AmigaOS which fixes graphics problems in some programs using these.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reported-by: Rene Engel <ReneEngel80@emailn.de>
Tested-by: Rene Engel <ReneEngel80@emailn.de>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <17ef3c59dc7868f75034e9ebe21e2999c8f718d4.1677445307.git.balaton@eik.bme.hu>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

hw/display/sm501.c

@@ -754,7 +754,7 @@ static void sm501_2d_operation(SM501State *s)
         }
 
         if ((rop_mode && rop == 0x5) || (!rop_mode && rop == 0x55)) {
-            /* Invert dest, is there a way to do this with pixman? */
+            /* DSTINVERT, is there a way to do this with pixman? */
             unsigned int x, y, i;
             uint8_t *d = s->local_mem + dst_base;
 
@@ -764,6 +764,34 @@ static void sm501_2d_operation(SM501State *s)
                     stn_he_p(&d[i], bypp, ~ldn_he_p(&d[i], bypp));
                 }
             }
+        } else if (!rop_mode && rop == 0x99) {
+            /* DSxn, is there a way to do this with pixman? */
+            unsigned int x, y, i, j;
+            uint8_t *sp = s->local_mem + src_base;
+            uint8_t *d = s->local_mem + dst_base;
+
+            for (y = 0; y < height; y++) {
+                i = (dst_x + (dst_y + y) * dst_pitch) * bypp;
+                j = (src_x + (src_y + y) * src_pitch) * bypp;
+                for (x = 0; x < width; x++, i += bypp, j += bypp) {
+                    stn_he_p(&d[i], bypp,
+                             ~(ldn_he_p(&sp[j], bypp) ^ ldn_he_p(&d[i], bypp)));
+                }
+            }
+        } else if (!rop_mode && rop == 0xee) {
+            /* SRCPAINT, is there a way to do this with pixman? */
+            unsigned int x, y, i, j;
+            uint8_t *sp = s->local_mem + src_base;
+            uint8_t *d = s->local_mem + dst_base;
+
+            for (y = 0; y < height; y++) {
+                i = (dst_x + (dst_y + y) * dst_pitch) * bypp;
+                j = (src_x + (src_y + y) * src_pitch) * bypp;
+                for (x = 0; x < width; x++, i += bypp, j += bypp) {
+                    stn_he_p(&d[i], bypp,
+                             ldn_he_p(&sp[j], bypp) | ldn_he_p(&d[i], bypp));
+                }
+            }
         } else {
             /* Do copy src for unimplemented ops, better than unpainted area */
             if ((rop_mode && (rop != 0xc || rop2_source_is_pattern)) ||