Ticket #8055: drawbomp2.diff

scummvm/scumm/gfx.cpp

@@ -3068 +3068 @@
 
 static byte blend(byte *pal, byte method, int dest_color)
 {
-        double val = 1.0;
+        int val = 0;
         int cache = 0;
 
+        // FIXME: Check if this gives the correct blending for the Dig
+        // inventory box and conversation menus. For now, I have deliberately
+        // selected them so that the subsequent multiplication and shift could
+        // be replaced by just a shift.
+
         switch (method) {
                 case 1:
                         cache = 0;
-                        val = 0.5;
+                        val = 128;
                         break;
 
                 case 2:
                         cache = 1;
-                        val = 0.4;
+                        val = 64;
                         break;
 
                 case 3:
                         cache = 2;
-                        val = 1.1;
+                        val = 256;
                         break;
 
                 case 255:
@@ -3099 +3104 @@
                 byte g = *(pal + 3 * dest_color + 1);
                 byte b = *(pal + 3 * dest_color + 2);
 
-                int new_r = (int) (val * r + 0.5);
-                int new_g = (int) (val * g + 0.5);
-                int new_b = (int) (val * b + 0.5);
+                int new_r = (val * r) >> 8;
+                int new_g = (val * g) >> 8;
+                int new_b = (val * b) >> 8;
 
                 if (new_r > 255)
                         new_r = 255;
@@ -3117 +3122 @@
 }
 
 // param3= clipping
-
 // param2= mirror
-
 // param1= never used ?
+
 void Scumm::drawBomp(BompDrawData *bd, int param1, byte *dataPtr, int param2, int param3)
 {
         byte *scale_rows = NULL;
@@ -3142 +3146 @@
                 }
         }
 
-        if (bd->scale_y != 255) {       
+        if (bd->scale_y != 255) {
                 scale_cols = (byte *) calloc(bd->srcwidth, 1);
                 if (scale_cols == NULL) {
                         warning("drawBomp: out of memory");
+                        if (scale_rows)
+                                free(scale_rows);
                         return;
                 }
         }
@@ -3166 +3172 @@
                         scale_rows[(i * 255) / bd->scale_y] = 1;
         }
 
+        // FIXME: Be more intelligent about clearing the blend cache. It
+        // should be possible to clear it only for the parts of the palette
+        // that have changed since the last time.
+
         clear_blend_cache();
 
         dest += bd->x;
         src = bd->dataptr;
+
         for (src_y = 0, dst_y = bd->y; src_y < bd->srcheight; src_y++) {
                 byte code, color;
                 uint len, num;
                 byte *d = dest;
 
-                if (dst_y < 0 || dst_y >= bd->outheight) {
+                if (dst_y < 0 || dst_y >= bd->outheight || (bd->scale_y != 255 && !scale_rows[src_y])) {
                         src += READ_LE_UINT16(src) + 2;
                         continue;
                 }
@@ -3193 +3204 @@
                         len -= num;
                         if (code & 1) {
                                 color = *src++;
-                                if (bd->scale_y == 255 || scale_rows[src_y]) {
-                                        do {
-                                                if (dst_x >= 0 && dst_x < bd->outwidth && (bd->scale_x || scale_cols[src_x]))
+                                for (i = 0; i < num; i++) {
+                                        if (bd->scale_x == 255 || scale_cols[src_x]) {
+                                                if (dst_x >= 0 && dst_x < bd->outwidth)
                                                         *d = blend(_currentPalette, color, *d);
-                                                if (bd->scale_x == 255 || scale_cols[src_x]) {
-                                                        d++;
-                                                        dst_x++;
-                                                }
-                                                src_x++;
-                                        } while (--num);
-                                } else {
-                                        src_x += num;
-                                        dst_x += num;
+                                                d++;
+                                                dst_x++;
+                                        }
+                                        src_x++;
                                 }
                         } else {
-                                if (bd->scale_y == 255 || scale_rows[src_y]) {
-                                        for (i = 0; i < num; i++) {
-                                                if (dst_x >= 0 && dst_x < bd->outwidth && (bd->scale_x || scale_cols[src_x]))
+                                for (i = 0; i < num; i++) {
+                                        if (bd->scale_x == 255 || scale_cols[src_x]) {
+                                                if (dst_x >= 0 && dst_x < bd->outwidth)
                                                         *d = blend(_currentPalette, src[i], *d);
-                                                if (bd->scale_x == 255 || scale_cols[src_x]) {
-                                                        d++;
-                                                        dst_x++;
-                                                }
-                                                src_x++;
+                                                d++;
+                                                dst_x++;
                                         }
-                                } else {
-                                        dst_x += num;
-                                        src_x += num;
+                                        src_x++;
                                 }
                                 src += num;
                         }
                 }
-                if (bd->scale_y == 255 || scale_rows[src_y]) {
-                        dest += bd->outwidth;
-                        dst_y++;
-                }
+                dest += bd->outwidth;
+                dst_y++;
         }
 
         if (scale_rows)