Extend blitting support for all <8bpp formats

src/video/SDL_blit_0.c

@@ -27,8 +27,11 @@
 
 /* Functions to blit from bitmaps to other surfaces */
 
-static void BlitBto1(SDL_BlitInfo *info)
+SDL_FORCE_INLINE void BlitBto1(SDL_BlitInfo *info, const Uint32 srcbpp)
 {
+    const Uint32 mask = (1 << srcbpp) - 1;
+    const Uint32 align = (8 / srcbpp) - 1;
+
     int c;
     int width, height;
     Uint8 *src, *map, *dst;
@@ -42,22 +45,28 @@ static void BlitBto1(SDL_BlitInfo *info)
     dst = info->dst;
     dstskip = info->dst_skip;
     map = info->table;
-    srcskip += width - (width + 7) / 8;
+
+    if (srcbpp == 4)
+        srcskip += width - (width + 1) / 2;
+    else if (srcbpp == 2)
+        srcskip += width - (width + 3) / 4;
+    else if (srcbpp == 1)
+        srcskip += width - (width + 7) / 8;
 
     if (map) {
-        if (info->src_fmt->format == SDL_PIXELFORMAT_INDEX1LSB) {
+        if (SDL_PIXELORDER(info->src_fmt->format) == SDL_BITMAPORDER_4321) {
             while (height--) {
                 Uint8 byte = 0, bit;
                 for (c = 0; c < width; ++c) {
-                    if (!(c & 7)) {
+                    if (!(c & align)) {
                         byte = *src++;
                     }
-                    bit = (byte & 0x01);
+                    bit = (byte & mask);
                     if (1) {
                         *dst = map[bit];
                     }
                     dst++;
-                    byte >>= 1;
+                    byte >>= srcbpp;
                 }
                 src += srcskip;
                 dst += dstskip;
@@ -66,34 +75,34 @@ static void BlitBto1(SDL_BlitInfo *info)
             while (height--) {
                 Uint8 byte = 0, bit;
                 for (c = 0; c < width; ++c) {
-                    if (!(c & 7)) {
+                    if (!(c & align)) {
                         byte = *src++;
                     }
-                    bit = (byte & 0x80) >> 7;
+                    bit = (byte >> (8 - srcbpp)) & mask;
                     if (1) {
                         *dst = map[bit];
                     }
                     dst++;
-                    byte <<= 1;
+                    byte <<= srcbpp;
                 }
                 src += srcskip;
                 dst += dstskip;
             }
         }
     } else {
-        if (info->src_fmt->format == SDL_PIXELFORMAT_INDEX1LSB) {
+        if (SDL_PIXELORDER(info->src_fmt->format) == SDL_BITMAPORDER_4321) {
             while (height--) {
                 Uint8 byte = 0, bit;
                 for (c = 0; c < width; ++c) {
-                    if (!(c & 7)) {
+                    if (!(c & align)) {
                         byte = *src++;
                     }
-                    bit = (byte & 0x01);
+                    bit = (byte & mask);
                     if (1) {
                         *dst = bit;
                     }
                     dst++;
-                    byte >>= 1;
+                    byte >>= srcbpp;
                 }
                 src += srcskip;
                 dst += dstskip;
@@ -102,15 +111,15 @@ static void BlitBto1(SDL_BlitInfo *info)
             while (height--) {
                 Uint8 byte = 0, bit;
                 for (c = 0; c < width; ++c) {
-                    if (!(c & 7)) {
+                    if (!(c & align)) {
                         byte = *src++;
                     }
-                    bit = (byte & 0x80) >> 7;
+                    bit = (byte >> (8 - srcbpp)) & mask;
                     if (1) {
                         *dst = bit;
                     }
                     dst++;
-                    byte <<= 1;
+                    byte <<= srcbpp;
                 }
                 src += srcskip;
                 dst += dstskip;
@@ -119,8 +128,11 @@ static void BlitBto1(SDL_BlitInfo *info)
     }
 }
 
-static void BlitBto2(SDL_BlitInfo *info)
+SDL_FORCE_INLINE void BlitBto2(SDL_BlitInfo *info, const Uint32 srcbpp)
 {
+    const Uint32 mask = (1 << srcbpp) - 1;
+    const Uint32 align = (8 / srcbpp) - 1;
+
     int c;
     int width, height;
     Uint8 *src;
@@ -135,20 +147,26 @@ static void BlitBto2(SDL_BlitInfo *info)
     dst = (Uint16 *)info->dst;
     dstskip = info->dst_skip / 2;
     map = (Uint16 *)info->table;
-    srcskip += width - (width + 7) / 8;
 
-    if (info->src_fmt->format == SDL_PIXELFORMAT_INDEX1LSB) {
+    if (srcbpp == 4)
+        srcskip += width - (width + 1) / 2;
+    else if (srcbpp == 2)
+        srcskip += width - (width + 3) / 4;
+    else if (srcbpp == 1)
+        srcskip += width - (width + 7) / 8;
+
+    if (SDL_PIXELORDER(info->src_fmt->format) == SDL_BITMAPORDER_4321) {
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x01);
+                bit = (byte & mask);
                 if (1) {
                     *dst = map[bit];
                 }
-                byte >>= 1;
+                byte >>= srcbpp;
                 dst++;
             }
             src += srcskip;
@@ -158,14 +176,14 @@ static void BlitBto2(SDL_BlitInfo *info)
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x80) >> 7;
+                bit = (byte >> (8 - srcbpp)) & mask;
                 if (1) {
                     *dst = map[bit];
                 }
-                byte <<= 1;
+                byte <<= srcbpp;
                 dst++;
             }
             src += srcskip;
@@ -174,8 +192,11 @@ static void BlitBto2(SDL_BlitInfo *info)
     }
 }
 
-static void BlitBto3(SDL_BlitInfo *info)
+SDL_FORCE_INLINE void BlitBto3(SDL_BlitInfo *info, const Uint32 srcbpp)
 {
+    const Uint32 mask = (1 << srcbpp) - 1;
+    const Uint32 align = (8 / srcbpp) - 1;
+
     int c, o;
     int width, height;
     Uint8 *src, *map, *dst;
@@ -189,23 +210,29 @@ static void BlitBto3(SDL_BlitInfo *info)
     dst = info->dst;
     dstskip = info->dst_skip;
     map = info->table;
-    srcskip += width - (width + 7) / 8;
 
-    if (info->src_fmt->format == SDL_PIXELFORMAT_INDEX1LSB) {
+    if (srcbpp == 4)
+        srcskip += width - (width + 1) / 2;
+    else if (srcbpp == 2)
+        srcskip += width - (width + 3) / 4;
+    else if (srcbpp == 1)
+        srcskip += width - (width + 7) / 8;
+
+    if (SDL_PIXELORDER(info->src_fmt->format) == SDL_BITMAPORDER_4321) {
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x01);
+                bit = (byte & mask);
                 if (1) {
                     o = bit * 4;
                     dst[0] = map[o++];
                     dst[1] = map[o++];
                     dst[2] = map[o++];
                 }
-                byte >>= 1;
+                byte >>= srcbpp;
                 dst += 3;
             }
             src += srcskip;
@@ -215,17 +242,17 @@ static void BlitBto3(SDL_BlitInfo *info)
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x80) >> 7;
+                bit = (byte >> (8 - srcbpp)) & mask;
                 if (1) {
                     o = bit * 4;
                     dst[0] = map[o++];
                     dst[1] = map[o++];
                     dst[2] = map[o++];
                 }
-                byte <<= 1;
+                byte <<= srcbpp;
                 dst += 3;
             }
             src += srcskip;
@@ -234,8 +261,11 @@ static void BlitBto3(SDL_BlitInfo *info)
     }
 }
 
-static void BlitBto4(SDL_BlitInfo *info)
+SDL_FORCE_INLINE void BlitBto4(SDL_BlitInfo *info, const Uint32 srcbpp)
 {
+    const Uint32 mask = (1 << srcbpp) - 1;
+    const Uint32 align = (8 / srcbpp) - 1;
+
     int width, height;
     Uint8 *src;
     Uint32 *map, *dst;
@@ -250,20 +280,26 @@ static void BlitBto4(SDL_BlitInfo *info)
     dst = (Uint32 *)info->dst;
     dstskip = info->dst_skip / 4;
     map = (Uint32 *)info->table;
-    srcskip += width - (width + 7) / 8;
 
-    if (info->src_fmt->format == SDL_PIXELFORMAT_INDEX1LSB) {
+    if (srcbpp == 4)
+        srcskip += width - (width + 1) / 2;
+    else if (srcbpp == 2)
+        srcskip += width - (width + 3) / 4;
+    else if (srcbpp == 1)
+        srcskip += width - (width + 7) / 8;
+
+    if (SDL_PIXELORDER(info->src_fmt->format) == SDL_BITMAPORDER_4321) {
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x01);
+                bit = (byte & mask);
                 if (1) {
                     *dst = map[bit];
                 }
-                byte >>= 1;
+                byte >>= srcbpp;
                 dst++;
             }
             src += srcskip;
@@ -273,14 +309,14 @@ static void BlitBto4(SDL_BlitInfo *info)
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x80) >> 7;
+                bit = (byte >> (8 - srcbpp)) & mask;
                 if (1) {
                     *dst = map[bit];
                 }
-                byte <<= 1;
+                byte <<= srcbpp;
                 dst++;
             }
             src += srcskip;
@@ -289,8 +325,11 @@ static void BlitBto4(SDL_BlitInfo *info)
     }
 }
 
-static void BlitBto1Key(SDL_BlitInfo *info)
+SDL_FORCE_INLINE void BlitBto1Key(SDL_BlitInfo *info, const Uint32 srcbpp)
 {
+    const Uint32 mask = (1 << srcbpp) - 1;
+    const Uint32 align = (8 / srcbpp) - 1;
+
     int width = info->dst_w;
     int height = info->dst_h;
     Uint8 *src = info->src;
@@ -302,22 +341,27 @@ static void BlitBto1Key(SDL_BlitInfo *info)
     int c;
 
     /* Set up some basic variables */
-    srcskip += width - (width + 7) / 8;
+    if (srcbpp == 4)
+        srcskip += width - (width + 1) / 2;
+    else if (srcbpp == 2)
+        srcskip += width - (width + 3) / 4;
+    else if (srcbpp == 1)
+        srcskip += width - (width + 7) / 8;
 
     if (palmap) {
-        if (info->src_fmt->format == SDL_PIXELFORMAT_INDEX1LSB) {
+        if (SDL_PIXELORDER(info->src_fmt->format) == SDL_BITMAPORDER_4321) {
             while (height--) {
                 Uint8 byte = 0, bit;
                 for (c = 0; c < width; ++c) {
-                    if (!(c & 7)) {
+                    if (!(c & align)) {
                         byte = *src++;
                     }
-                    bit = (byte & 0x01);
+                    bit = (byte & mask);
                     if (bit != ckey) {
                         *dst = palmap[bit];
                     }
                     dst++;
-                    byte >>= 1;
+                    byte >>= srcbpp;
                 }
                 src += srcskip;
                 dst += dstskip;
@@ -326,34 +370,34 @@ static void BlitBto1Key(SDL_BlitInfo *info)
             while (height--) {
                 Uint8 byte = 0, bit;
                 for (c = 0; c < width; ++c) {
-                    if (!(c & 7)) {
+                    if (!(c & align)) {
                         byte = *src++;
                     }
-                    bit = (byte & 0x80) >> 7;
+                    bit = (byte >> (8 - srcbpp)) & mask;
                     if (bit != ckey) {
                         *dst = palmap[bit];
                     }
                     dst++;
-                    byte <<= 1;
+                    byte <<= srcbpp;
                 }
                 src += srcskip;
                 dst += dstskip;
             }
         }
     } else {
-        if (info->src_fmt->format == SDL_PIXELFORMAT_INDEX1LSB) {
+        if (SDL_PIXELORDER(info->src_fmt->format) == SDL_BITMAPORDER_4321) {
             while (height--) {
                 Uint8 byte = 0, bit;
                 for (c = 0; c < width; ++c) {
-                    if (!(c & 7)) {
+                    if (!(c & align)) {
                         byte = *src++;
                     }
-                    bit = (byte & 0x01);
+                    bit = (byte & mask);
                     if (bit != ckey) {
                         *dst = bit;
                     }
                     dst++;
-                    byte >>= 1;
+                    byte >>= srcbpp;
                 }
                 src += srcskip;
                 dst += dstskip;
@@ -362,15 +406,15 @@ static void BlitBto1Key(SDL_BlitInfo *info)
             while (height--) {
                 Uint8 byte = 0, bit;
                 for (c = 0; c < width; ++c) {
-                    if (!(c & 7)) {
+                    if (!(c & align)) {
                         byte = *src++;
                     }
-                    bit = (byte & 0x80) >> 7;
+                    bit = (byte >> (8 - srcbpp)) & mask;
                     if (bit != ckey) {
                         *dst = bit;
                     }
                     dst++;
-                    byte <<= 1;
+                    byte <<= srcbpp;
                 }
                 src += srcskip;
                 dst += dstskip;
@@ -379,8 +423,11 @@ static void BlitBto1Key(SDL_BlitInfo *info)
     }
 }
 
-static void BlitBto2Key(SDL_BlitInfo *info)
+SDL_FORCE_INLINE void BlitBto2Key(SDL_BlitInfo *info, const Uint32 srcbpp)
 {
+    const Uint32 mask = (1 << srcbpp) - 1;
+    const Uint32 align = (8 / srcbpp) - 1;
+
     int width = info->dst_w;
     int height = info->dst_h;
     Uint8 *src = info->src;
@@ -392,21 +439,26 @@ static void BlitBto2Key(SDL_BlitInfo *info)
     int c;
 
     /* Set up some basic variables */
-    srcskip += width - (width + 7) / 8;
+    if (srcbpp == 4)
+        srcskip += width - (width + 1) / 2;
+    else if (srcbpp == 2)
+        srcskip += width - (width + 3) / 4;
+    else if (srcbpp == 1)
+        srcskip += width - (width + 7) / 8;
     dstskip /= 2;
 
-    if (info->src_fmt->format == SDL_PIXELFORMAT_INDEX1LSB) {
+    if (SDL_PIXELORDER(info->src_fmt->format) == SDL_BITMAPORDER_4321) {
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x01);
+                bit = (byte & mask);
                 if (bit != ckey) {
                     *dstp = ((Uint16 *)palmap)[bit];
                 }
-                byte >>= 1;
+                byte >>= srcbpp;
                 dstp++;
             }
             src += srcskip;
@@ -416,14 +468,14 @@ static void BlitBto2Key(SDL_BlitInfo *info)
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x80) >> 7;
+                bit = (byte >> (8 - srcbpp)) & mask;
                 if (bit != ckey) {
                     *dstp = ((Uint16 *)palmap)[bit];
                 }
-                byte <<= 1;
+                byte <<= srcbpp;
                 dstp++;
             }
             src += srcskip;
@@ -432,8 +484,11 @@ static void BlitBto2Key(SDL_BlitInfo *info)
     }
 }
 
-static void BlitBto3Key(SDL_BlitInfo *info)
+SDL_FORCE_INLINE void BlitBto3Key(SDL_BlitInfo *info, const Uint32 srcbpp)
 {
+    const Uint32 mask = (1 << srcbpp) - 1;
+    const Uint32 align = (8 / srcbpp) - 1;
+
     int width = info->dst_w;
     int height = info->dst_h;
     Uint8 *src = info->src;
@@ -445,20 +500,25 @@ static void BlitBto3Key(SDL_BlitInfo *info)
     int c;
 
     /* Set up some basic variables */
-    srcskip += width - (width + 7) / 8;
-
-    if (info->src_fmt->format == SDL_PIXELFORMAT_INDEX1LSB) {
+    if (srcbpp == 4)
+        srcskip += width - (width + 1) / 2;
+    else if (srcbpp == 2)
+        srcskip += width - (width + 3) / 4;
+    else if (srcbpp == 1)
+        srcskip += width - (width + 7) / 8;
+
+    if (SDL_PIXELORDER(info->src_fmt->format) == SDL_BITMAPORDER_4321) {
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x01);
+                bit = (byte & mask);
                 if (bit != ckey) {
                     SDL_memcpy(dst, &palmap[bit * 4], 3);
                 }
-                byte >>= 1;
+                byte >>= srcbpp;
                 dst += 3;
             }
             src += srcskip;
@@ -468,14 +528,14 @@ static void BlitBto3Key(SDL_BlitInfo *info)
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x80) >> 7;
+                bit = (byte >> (8 - srcbpp)) & mask;
                 if (bit != ckey) {
                     SDL_memcpy(dst, &palmap[bit * 4], 3);
                 }
-                byte <<= 1;
+                byte <<= srcbpp;
                 dst += 3;
             }
             src += srcskip;
@@ -484,8 +544,11 @@ static void BlitBto3Key(SDL_BlitInfo *info)
     }
 }
 
-static void BlitBto4Key(SDL_BlitInfo *info)
+SDL_FORCE_INLINE void BlitBto4Key(SDL_BlitInfo *info, const Uint32 srcbpp)
 {
+    const Uint32 mask = (1 << srcbpp) - 1;
+    const Uint32 align = (8 / srcbpp) - 1;
+
     int width = info->dst_w;
     int height = info->dst_h;
     Uint8 *src = info->src;
@@ -497,21 +560,26 @@ static void BlitBto4Key(SDL_BlitInfo *info)
     int c;
 
     /* Set up some basic variables */
-    srcskip += width - (width + 7) / 8;
+    if (srcbpp == 4)
+        srcskip += width - (width + 1) / 2;
+    else if (srcbpp == 2)
+        srcskip += width - (width + 3) / 4;
+    else if (srcbpp == 1)
+        srcskip += width - (width + 7) / 8;
     dstskip /= 4;
 
-    if (info->src_fmt->format == SDL_PIXELFORMAT_INDEX1LSB) {
+    if (SDL_PIXELORDER(info->src_fmt->format) == SDL_BITMAPORDER_4321) {
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x01);
+                bit = (byte & mask);
                 if (bit != ckey) {
                     *dstp = ((Uint32 *)palmap)[bit];
                 }
-                byte >>= 1;
+                byte >>= srcbpp;
                 dstp++;
             }
             src += srcskip;
@@ -521,14 +589,14 @@ static void BlitBto4Key(SDL_BlitInfo *info)
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x80) >> 7;
+                bit = (byte >> (8 - srcbpp)) & mask;
                 if (bit != ckey) {
                     *dstp = ((Uint32 *)palmap)[bit];
                 }
-                byte <<= 1;
+                byte <<= srcbpp;
                 dstp++;
             }
             src += srcskip;
@@ -537,8 +605,11 @@ static void BlitBto4Key(SDL_BlitInfo *info)
     }
 }
 
-static void BlitBtoNAlpha(SDL_BlitInfo *info)
+SDL_FORCE_INLINE void BlitBtoNAlpha(SDL_BlitInfo *info, const Uint32 srcbpp)
 {
+    const Uint32 mask = (1 << srcbpp) - 1;
+    const Uint32 align = (8 / srcbpp) - 1;
+
     int width = info->dst_w;
     int height = info->dst_h;
     Uint8 *src = info->src;
@@ -556,16 +627,21 @@ static void BlitBtoNAlpha(SDL_BlitInfo *info)
 
     /* Set up some basic variables */
     dstbpp = dstfmt->BytesPerPixel;
-    srcskip += width - (width + 7) / 8;
-
-    if (info->src_fmt->format == SDL_PIXELFORMAT_INDEX1LSB) {
+    if (srcbpp == 4)
+        srcskip += width - (width + 1) / 2;
+    else if (srcbpp == 2)
+        srcskip += width - (width + 3) / 4;
+    else if (srcbpp == 1)
+        srcskip += width - (width + 7) / 8;
+
+    if (SDL_PIXELORDER(info->src_fmt->format) == SDL_BITMAPORDER_4321) {
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x01);
+                bit = (byte & mask);
                 if (1) {
                     sR = srcpal[bit].r;
                     sG = srcpal[bit].g;
@@ -574,7 +650,7 @@ static void BlitBtoNAlpha(SDL_BlitInfo *info)
                     ALPHA_BLEND_RGBA(sR, sG, sB, A, dR, dG, dB, dA);
                     ASSEMBLE_RGBA(dst, dstbpp, dstfmt, dR, dG, dB, dA);
                 }
-                byte >>= 1;
+                byte >>= srcbpp;
                 dst += dstbpp;
             }
             src += srcskip;
@@ -584,10 +660,10 @@ static void BlitBtoNAlpha(SDL_BlitInfo *info)
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x80) >> 7;
+                bit = (byte >> (8 - srcbpp)) & mask;
                 if (1) {
                     sR = srcpal[bit].r;
                     sG = srcpal[bit].g;
@@ -596,7 +672,7 @@ static void BlitBtoNAlpha(SDL_BlitInfo *info)
                     ALPHA_BLEND_RGBA(sR, sG, sB, A, dR, dG, dB, dA);
                     ASSEMBLE_RGBA(dst, dstbpp, dstfmt, dR, dG, dB, dA);
                 }
-                byte <<= 1;
+                byte <<= srcbpp;
                 dst += dstbpp;
             }
             src += srcskip;
@@ -605,8 +681,11 @@ static void BlitBtoNAlpha(SDL_BlitInfo *info)
     }
 }
 
-static void BlitBtoNAlphaKey(SDL_BlitInfo *info)
+SDL_FORCE_INLINE void BlitBtoNAlphaKey(SDL_BlitInfo *info, const Uint32 srcbpp)
 {
+    const Uint32 mask = (1 << srcbpp) - 1;
+    const Uint32 align = (8 / srcbpp) - 1;
+
     int width = info->dst_w;
     int height = info->dst_h;
     Uint8 *src = info->src;
@@ -626,16 +705,21 @@ static void BlitBtoNAlphaKey(SDL_BlitInfo *info)
 
     /* Set up some basic variables */
     dstbpp = dstfmt->BytesPerPixel;
-    srcskip += width - (width + 7) / 8;
-
-    if (info->src_fmt->format == SDL_PIXELFORMAT_INDEX1LSB) {
+    if (srcbpp == 4)
+        srcskip += width - (width + 1) / 2;
+    else if (srcbpp == 2)
+        srcskip += width - (width + 3) / 4;
+    else if (srcbpp == 1)
+        srcskip += width - (width + 7) / 8;
+
+    if (SDL_PIXELORDER(info->src_fmt->format) == SDL_BITMAPORDER_4321) {
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x01);
+                bit = (byte & mask);
                 if (bit != ckey) {
                     sR = srcpal[bit].r;
                     sG = srcpal[bit].g;
@@ -644,7 +728,7 @@ static void BlitBtoNAlphaKey(SDL_BlitInfo *info)
                     ALPHA_BLEND_RGBA(sR, sG, sB, A, dR, dG, dB, dA);
                     ASSEMBLE_RGBA(dst, dstbpp, dstfmt, dR, dG, dB, dA);
                 }
-                byte >>= 1;
+                byte >>= srcbpp;
                 dst += dstbpp;
             }
             src += srcskip;
@@ -654,10 +738,10 @@ static void BlitBtoNAlphaKey(SDL_BlitInfo *info)
         while (height--) {
             Uint8 byte = 0, bit;
             for (c = 0; c < width; ++c) {
-                if (!(c & 7)) {
+                if (!(c & align)) {
                     byte = *src++;
                 }
-                bit = (byte & 0x80) >> 7;
+                bit = (byte >> (8 - srcbpp)) & mask;
                 if (bit != ckey) {
                     sR = srcpal[bit].r;
                     sG = srcpal[bit].g;
@@ -666,7 +750,7 @@ static void BlitBtoNAlphaKey(SDL_BlitInfo *info)
                     ALPHA_BLEND_RGBA(sR, sG, sB, A, dR, dG, dB, dA);
                     ASSEMBLE_RGBA(dst, dstbpp, dstfmt, dR, dG, dB, dA);
                 }
-                byte <<= 1;
+                byte <<= srcbpp;
                 dst += dstbpp;
             }
             src += srcskip;
@@ -675,121 +759,226 @@ static void BlitBtoNAlphaKey(SDL_BlitInfo *info)
     }
 }
 
-static const SDL_BlitFunc bitmap_blit[] = {
-    (SDL_BlitFunc)NULL, BlitBto1, BlitBto2, BlitBto3, BlitBto4
+
+
+static void Blit1bto1(SDL_BlitInfo *info) {
+    BlitBto1(info, 1);
+}
+
+static void Blit1bto2(SDL_BlitInfo *info) {
+    BlitBto2(info, 1);
+}
+
+static void Blit1bto3(SDL_BlitInfo *info) {
+    BlitBto3(info, 1);
+}
+
+static void Blit1bto4(SDL_BlitInfo *info) {
+    BlitBto4(info, 1);
+}
+
+static const SDL_BlitFunc bitmap_blit_1b[] = {
+    (SDL_BlitFunc)NULL, Blit1bto1, Blit1bto2, Blit1bto3, Blit1bto4
 };
 
-static const SDL_BlitFunc colorkey_blit[] = {
-    (SDL_BlitFunc)NULL, BlitBto1Key, BlitBto2Key, BlitBto3Key, BlitBto4Key
+static void Blit1bto1Key(SDL_BlitInfo *info) {
+    BlitBto1Key(info, 1);
+}
+
+static void Blit1bto2Key(SDL_BlitInfo *info) {
+    BlitBto2Key(info, 1);
+}
+
+static void Blit1bto3Key(SDL_BlitInfo *info) {
+    BlitBto3Key(info, 1);
+}
+
+static void Blit1bto4Key(SDL_BlitInfo *info) {
+    BlitBto4Key(info, 1);
+}
+
+static const SDL_BlitFunc colorkey_blit_1b[] = {
+    (SDL_BlitFunc)NULL, Blit1bto1Key, Blit1bto2Key, Blit1bto3Key, Blit1bto4Key
 };
 
-static void Blit4bto4(SDL_BlitInfo *info)
+static void Blit1btoNAlpha(SDL_BlitInfo *info)
 {
-    int width = info->dst_w;
-    int height = info->dst_h;
-    Uint8 *src = info->src;
-    Uint32 *dst = (Uint32 *)info->dst;
-    int srcskip = info->src_skip;
-    int dstskip = info->dst_skip;
-    Uint32 *map = (Uint32 *)info->table;
-    int c;
+    BlitBtoNAlpha(info, 1);
+}
 
-    /* Set up some basic variables */
-    srcskip += width - (width + 1) / 2;
+static void Blit1btoNAlphaKey(SDL_BlitInfo *info)
+{
+    BlitBtoNAlphaKey(info, 1);
+}
 
-    while (height--) {
-        Uint8 byte = 0, bit;
-        for (c = 0; c < width; ++c) {
-            if (!(c & 0x1)) {
-                byte = *src++;
-            }
-            bit = (byte & 0xF0) >> 4;
-            if (1) {
-                *dst = map[bit];
-            }
-            byte <<= 4;
-            dst++;
-        }
-        src += srcskip;
-        dst = (Uint32 *)((Uint8 *)dst + dstskip);
-    }
+
+
+static void Blit2bto1(SDL_BlitInfo *info) {
+    BlitBto1(info, 2);
 }
 
-static void Blit4bto4Key(SDL_BlitInfo *info)
+static void Blit2bto2(SDL_BlitInfo *info) {
+    BlitBto2(info, 2);
+}
+
+static void Blit2bto3(SDL_BlitInfo *info) {
+    BlitBto3(info, 2);
+}
+
+static void Blit2bto4(SDL_BlitInfo *info) {
+    BlitBto4(info, 2);
+}
+
+static const SDL_BlitFunc bitmap_blit_2b[] = {
+    (SDL_BlitFunc)NULL, Blit2bto1, Blit2bto2, Blit2bto3, Blit2bto4
+};
+
+static void Blit2bto1Key(SDL_BlitInfo *info) {
+    BlitBto1Key(info, 2);
+}
+
+static void Blit2bto2Key(SDL_BlitInfo *info) {
+    BlitBto2Key(info, 2);
+}
+
+static void Blit2bto3Key(SDL_BlitInfo *info) {
+    BlitBto3Key(info, 2);
+}
+
+static void Blit2bto4Key(SDL_BlitInfo *info) {
+    BlitBto4Key(info, 2);
+}
+
+static const SDL_BlitFunc colorkey_blit_2b[] = {
+    (SDL_BlitFunc)NULL, Blit2bto1Key, Blit2bto2Key, Blit2bto3Key, Blit2bto4Key
+};
+
+static void Blit2btoNAlpha(SDL_BlitInfo *info)
 {
-    int width = info->dst_w;
-    int height = info->dst_h;
-    Uint8 *src = info->src;
-    Uint32 *dst = (Uint32 *)info->dst;
-    int srcskip = info->src_skip;
-    int dstskip = info->dst_skip;
-    Uint32 ckey = info->colorkey;
-    Uint32 *map = (Uint32 *)info->table;
-    int c;
+    BlitBtoNAlpha(info, 2);
+}
 
-    /* Set up some basic variables */
-    srcskip += width - (width + 1) / 2;
+static void Blit2btoNAlphaKey(SDL_BlitInfo *info)
+{
+    BlitBtoNAlphaKey(info, 2);
+}
 
-    while (height--) {
-        Uint8 byte = 0, bit;
-        for (c = 0; c < width; ++c) {
-            if (!(c & 0x1)) {
-                byte = *src++;
-            }
-            bit = (byte & 0xF0) >> 4;
-            if (bit != ckey) {
-                *dst = map[bit];
-            }
-            byte <<= 4;
-            dst++;
-        }
-        src += srcskip;
-        dst = (Uint32 *)((Uint8 *)dst + dstskip);
-    }
+
+
+static void Blit4bto1(SDL_BlitInfo *info) {
+    BlitBto1(info, 4);
+}
+
+static void Blit4bto2(SDL_BlitInfo *info) {
+    BlitBto2(info, 4);
+}
+
+static void Blit4bto3(SDL_BlitInfo *info) {
+    BlitBto3(info, 4);
+}
+
+static void Blit4bto4(SDL_BlitInfo *info) {
+    BlitBto4(info, 4);
+}
+
+static const SDL_BlitFunc bitmap_blit_4b[] = {
+    (SDL_BlitFunc)NULL, Blit4bto1, Blit4bto2, Blit4bto3, Blit4bto4
+};
+
+static void Blit4bto1Key(SDL_BlitInfo *info) {
+    BlitBto1Key(info, 4);
+}
+
+static void Blit4bto2Key(SDL_BlitInfo *info) {
+    BlitBto2Key(info, 4);
+}
+
+static void Blit4bto3Key(SDL_BlitInfo *info) {
+    BlitBto3Key(info, 4);
+}
+
+static void Blit4bto4Key(SDL_BlitInfo *info) {
+    BlitBto4Key(info, 4);
 }
 
+static const SDL_BlitFunc colorkey_blit_4b[] = {
+    (SDL_BlitFunc)NULL, Blit4bto1Key, Blit4bto2Key, Blit4bto3Key, Blit4bto4Key
+};
+
+static void Blit4btoNAlpha(SDL_BlitInfo *info)
+{
+    BlitBtoNAlpha(info, 4);
+}
+
+static void Blit4btoNAlphaKey(SDL_BlitInfo *info)
+{
+    BlitBtoNAlphaKey(info, 4);
+}
+
+
+
 SDL_BlitFunc SDL_CalculateBlit0(SDL_Surface *surface)
 {
     int which;
 
-    /* 4bits to 32bits */
-    if (surface->format->BitsPerPixel == 4) {
-        if (surface->map->dst->format->BytesPerPixel == 4) {
-            switch (surface->map->info.flags & ~SDL_COPY_RLE_MASK) {
-            case 0:
-                return Blit4bto4;
+    if (surface->map->dst->format->BitsPerPixel < 8) {
+        which = 0;
+    } else {
+        which = surface->map->dst->format->BytesPerPixel;
+    }
+
+    if (SDL_PIXELTYPE(surface->format->format) == SDL_PIXELTYPE_INDEX1) {
+        switch (surface->map->info.flags & ~SDL_COPY_RLE_MASK) {
+        case 0:
+            return bitmap_blit_1b[which];
 
-            case SDL_COPY_COLORKEY:
-                return Blit4bto4Key;
-            }
+        case SDL_COPY_COLORKEY:
+            return colorkey_blit_1b[which];
+
+        case SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
+            return which >= 2 ? Blit1btoNAlpha : (SDL_BlitFunc)NULL;
+
+        case SDL_COPY_COLORKEY | SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
+            return which >= 2 ? Blit1btoNAlphaKey : (SDL_BlitFunc)NULL;
         }
-        /* We don't fully support 4-bit packed pixel modes */
         return NULL;
     }
 
-    if (surface->format->BitsPerPixel != 1) {
-        /* We don't support sub 8-bit packed pixel modes */
-        return (SDL_BlitFunc) NULL;
-    }
-    if (surface->map->dst->format->BitsPerPixel < 8) {
-        which = 0;
-    } else {
-        which = surface->map->dst->format->BytesPerPixel;
+    if (SDL_PIXELTYPE(surface->format->format) == SDL_PIXELTYPE_INDEX2) {
+        switch (surface->map->info.flags & ~SDL_COPY_RLE_MASK) {
+        case 0:
+            return bitmap_blit_2b[which];
+
+        case SDL_COPY_COLORKEY:
+            return colorkey_blit_2b[which];
+
+        case SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
+            return which >= 2 ? Blit2btoNAlpha : (SDL_BlitFunc)NULL;
+
+        case SDL_COPY_COLORKEY | SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
+            return which >= 2 ? Blit2btoNAlphaKey : (SDL_BlitFunc)NULL;
+        }
+        return NULL;
     }
-    switch (surface->map->info.flags & ~SDL_COPY_RLE_MASK) {
-    case 0:
-        return bitmap_blit[which];
 
-    case SDL_COPY_COLORKEY:
-        return colorkey_blit[which];
+    if (SDL_PIXELTYPE(surface->format->format) == SDL_PIXELTYPE_INDEX4) {
+        switch (surface->map->info.flags & ~SDL_COPY_RLE_MASK) {
+        case 0:
+            return bitmap_blit_4b[which];
 
-    case SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
-        return which >= 2 ? BlitBtoNAlpha : (SDL_BlitFunc) NULL;
+        case SDL_COPY_COLORKEY:
+            return colorkey_blit_4b[which];
 
-    case SDL_COPY_COLORKEY | SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
-        return which >= 2 ? BlitBtoNAlphaKey : (SDL_BlitFunc) NULL;
+        case SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
+            return which >= 2 ? Blit4btoNAlpha : (SDL_BlitFunc)NULL;
+
+        case SDL_COPY_COLORKEY | SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
+            return which >= 2 ? Blit4btoNAlphaKey : (SDL_BlitFunc)NULL;
+        }
+        return NULL;
     }
-    return (SDL_BlitFunc) NULL;
+
+    return NULL;
 }
 
 #endif /* SDL_HAVE_BLIT_0 */