From f3e86b9fd38cc2727f75f509cea0a4235878b825 Mon Sep 17 00:00:00 2001
From: Sylvain <sylvain.becker@gmail.com>
Date: Tue, 15 Mar 2022 17:46:12 +0100
Subject: [PATCH] Fixed bug #2199: make SDL_blit_slow handles
 SDL_PIXELFORMAT_ARGB2101010, storing as RGBA

---
 src/video/SDL_blit.c      |  4 +---
 src/video/SDL_blit_slow.c | 47 ++++++++++++++++++++++++++-------------
 2 files changed, 33 insertions(+), 18 deletions(-)

diff --git a/src/video/SDL_blit.c b/src/video/SDL_blit.c
index dc4d7e9c3..fa6492f51 100644
--- a/src/video/SDL_blit.c
+++ b/src/video/SDL_blit.c
@@ -231,9 +231,7 @@ SDL_CalculateBlit(SDL_Surface * surface)
     if (map->identity && !(map->info.flags & ~SDL_COPY_RLE_DESIRED)) {
         blit = SDL_BlitCopy;
     } else if (surface->format->Rloss > 8 || dst->format->Rloss > 8) {
-        /* Greater than 8 bits per channel not supported yet */
-        SDL_InvalidateMap(map);
-        return SDL_SetError("Blit combination not supported");
+        blit = SDL_Blit_Slow;
     }
 #if SDL_HAVE_BLIT_0
     else if (surface->format->BitsPerPixel < 8 &&
diff --git a/src/video/SDL_blit_slow.c b/src/video/SDL_blit_slow.c
index a104517e8..df31a3b6a 100644
--- a/src/video/SDL_blit_slow.c
+++ b/src/video/SDL_blit_slow.c
@@ -46,6 +46,8 @@ SDL_Blit_Slow(SDL_BlitInfo * info)
     SDL_PixelFormat *dst_fmt = info->dst_fmt;
     int srcbpp = src_fmt->BytesPerPixel;
     int dstbpp = dst_fmt->BytesPerPixel;
+    int srcfmt_isnot_2101010 = (src_fmt->format != SDL_PIXELFORMAT_ARGB2101010);
+    int dstfmt_isnot_2101010 = (dst_fmt->format != SDL_PIXELFORMAT_ARGB2101010);
     Uint32 rgbmask = ~src_fmt->Amask;
     Uint32 ckey = info->colorkey & rgbmask;
 
@@ -62,14 +64,19 @@ SDL_Blit_Slow(SDL_BlitInfo * info)
         while (n--) {
             srcx = posx >> 16;
             src = (info->src + (srcy * info->src_pitch) + (srcx * srcbpp));
-            if (src_fmt->Amask) {
-                DISEMBLE_RGBA(src, srcbpp, src_fmt, srcpixel, srcR, srcG,
-                              srcB, srcA);
+            if (srcfmt_isnot_2101010) {
+                if (src_fmt->Amask) {
+                    DISEMBLE_RGBA(src, srcbpp, src_fmt, srcpixel, srcR, srcG, srcB, srcA);
+                } else {
+                    DISEMBLE_RGB(src, srcbpp, src_fmt, srcpixel, srcR, srcG, srcB);
+                    srcA = 0xFF;
+                }
             } else {
-                DISEMBLE_RGB(src, srcbpp, src_fmt, srcpixel, srcR, srcG,
-                             srcB);
-                srcA = 0xFF;
+                /* SDL_PIXELFORMAT_ARGB2101010 */
+                srcpixel = *((Uint32 *)(src));
+                RGBA_FROM_ARGB2101010(srcpixel, srcR, srcG, srcB, srcA);
             }
+
             if (flags & SDL_COPY_COLORKEY) {
                 /* srcpixel isn't set for 24 bpp */
                 if (srcbpp == 3) {
@@ -82,13 +89,17 @@ SDL_Blit_Slow(SDL_BlitInfo * info)
                     continue;
                 }
             }
-            if (dst_fmt->Amask) {
-                DISEMBLE_RGBA(dst, dstbpp, dst_fmt, dstpixel, dstR, dstG,
-                              dstB, dstA);
+            if (dstfmt_isnot_2101010) {
+                if (dst_fmt->Amask) {
+                    DISEMBLE_RGBA(dst, dstbpp, dst_fmt, dstpixel, dstR, dstG, dstB, dstA);
+                } else {
+                    DISEMBLE_RGB(dst, dstbpp, dst_fmt, dstpixel, dstR, dstG, dstB);
+                    dstA = 0xFF;
+                }
             } else {
-                DISEMBLE_RGB(dst, dstbpp, dst_fmt, dstpixel, dstR, dstG,
-                             dstB);
-                dstA = 0xFF;
+                /* SDL_PIXELFORMAT_ARGB2101010 */
+                dstpixel = *((Uint32 *)(dst));
+                RGBA_FROM_ARGB2101010(dstpixel, dstR, dstG, dstB, dstA);
             }
 
             if (flags & SDL_COPY_MODULATE_COLOR) {
@@ -151,10 +162,16 @@ SDL_Blit_Slow(SDL_BlitInfo * info)
                     dstA = 255;
                 break;
             }
-            if (dst_fmt->Amask) {
-                ASSEMBLE_RGBA(dst, dstbpp, dst_fmt, dstR, dstG, dstB, dstA);
+            if (dstfmt_isnot_2101010) {
+                if (dst_fmt->Amask) {
+                    ASSEMBLE_RGBA(dst, dstbpp, dst_fmt, dstR, dstG, dstB, dstA);
+                } else {
+                    ASSEMBLE_RGB(dst, dstbpp, dst_fmt, dstR, dstG, dstB);
+                }
             } else {
-                ASSEMBLE_RGB(dst, dstbpp, dst_fmt, dstR, dstG, dstB);
+                Uint32 Pixel;
+                ARGB2101010_FROM_RGBA(Pixel, dstR, dstG, dstB, dstA);
+                *(Uint32 *)dst = Pixel;
             }
             posx += incx;
             dst += dstbpp;