commit 0a0d2ae

Tightened sprite drawing

 1@@ -524,30 +524,25 @@ screen_deo_sprite(void)
 2 	const int ctrl = dev[0x2f];
 3 	const int flipx = ctrl & 0x10, dx = flipx ? -rDY : rDY;
 4 	const int flipy = ctrl & 0x20, dy = flipy ? -rDX : rDX;
 5+	const int row_start = flipx ? 0 : 7, row_delta = flipx ? 1 : -1;
 6+	const int col_start = flipy ? 7 : 0, col_delta = flipy ? -1 : 1;
 7 	const int layer = ctrl & 0x40, layer_mask = layer ? 0x3 : 0xc;
 8-	const int row_step = flipy ? -1 : 1, row_start = flipy ? 7 : 0;
 9-	const int is_2bpp = ctrl >> 7;
10-	const int addr_incr = rMA << (is_2bpp + 1);
11+	const int mode_2bpp = ctrl >> 7, addr_2bpp = mode_2bpp ? rMA << 2 : rMA << 1;
12 	const int blend = ctrl & 0xf;
13-	const Uint8 opaque_mask = alpha_lut[blend];
14-	const Uint8 *table = blend_lut[blend][layer >> 6];
15-	for(i = 0; i <= rML; i++, x += dx, y += dy, rA += addr_incr) {
16+	const Uint8 opaque = alpha_lut[blend], *table = blend_lut[blend][layer >> 6];
17+	for(i = 0; i <= rML; i++, x += dx, y += dy, rA += addr_2bpp) {
18 		const Uint16 x0 = x + 8, y0 = y + 8;
19 		if(x0 + 8 >= screen_wmar2 || y0 + 8 >= screen_hmar2) continue;
20 		Uint8 *dst = screen_layers + y0 * screen_wmar2 + x0;
21-		const Uint8 *rowptr = &ram[rA + row_start];
22-		for(j = 0; j < 8; j++, dst += screen_wmar2, rowptr += row_step) {
23-			Uint8 *d = dst, bits1 = rowptr[0], bits2 = is_2bpp ? rowptr[8] : 0;
24-			if(flipx)
25-				for(int k = 0; k < 8; k++, d++, bits1 >>= 1, bits2 >>= 1) {
26-					const int color = (bits1 & 1) | ((bits2 << 1) & 2);
27-					if(opaque_mask || color) *d = (*d & layer_mask) | table[color];
28-				}
29-			else
30-				for(int k = 0; k < 8; k++, d++, bits1 <<= 1, bits2 <<= 1) {
31-					const int color = (bits1 >> 7) | ((bits2 >> 6) & 2);
32-					if(opaque_mask || color) *d = (*d & layer_mask) | table[color];
33-				}
34+		const Uint8 *col = &ram[rA + col_start];
35+		for(j = 0; j < 8; j++, dst += screen_wmar2, col += col_delta) {
36+			Uint8 *d = dst;
37+			const int ch1 = *col, ch2 = mode_2bpp ? col[8] : 0;
38+			for(int k = 0, row = row_start; k < 8; k++, d++, row += row_delta) {
39+				const int color = ((ch1 >> row) & 1) | (((ch2 >> row) & 1) << 1);
40+				if(opaque || color)
41+					*d = (*d & layer_mask) | table[color];
42+			}
43 		}
44 	}
45 	if(!screen_reqdraw) {