Add SDL_PIXELFORMAT_INDEX2LSB and SDL_PIXELFORMAT_INDEX2MSB

include/SDL3/SDL_pixels.h

@@ -88,6 +88,7 @@ typedef enum
 {
     SDL_PIXELTYPE_UNKNOWN,
     SDL_PIXELTYPE_INDEX1,
+    SDL_PIXELTYPE_INDEX2,
     SDL_PIXELTYPE_INDEX4,
     SDL_PIXELTYPE_INDEX8,
     SDL_PIXELTYPE_PACKED8,
@@ -166,6 +167,7 @@ typedef enum
 #define SDL_ISPIXELFORMAT_INDEXED(format)   \
     (!SDL_ISPIXELFORMAT_FOURCC(format) && \
      ((SDL_PIXELTYPE(format) == SDL_PIXELTYPE_INDEX1) || \
+      (SDL_PIXELTYPE(format) == SDL_PIXELTYPE_INDEX2) || \
       (SDL_PIXELTYPE(format) == SDL_PIXELTYPE_INDEX4) || \
       (SDL_PIXELTYPE(format) == SDL_PIXELTYPE_INDEX8)))
 
@@ -208,6 +210,12 @@ typedef enum
     SDL_PIXELFORMAT_INDEX1MSB =
         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_INDEX1, SDL_BITMAPORDER_1234, 0,
                                1, 0),
+    SDL_PIXELFORMAT_INDEX2LSB =
+        SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_INDEX2, SDL_BITMAPORDER_4321, 0,
+                               2, 0),
+    SDL_PIXELFORMAT_INDEX2MSB =
+        SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_INDEX2, SDL_BITMAPORDER_1234, 0,
+                               2, 0),
     SDL_PIXELFORMAT_INDEX4LSB =
         SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_INDEX4, SDL_BITMAPORDER_4321, 0,
                                4, 0),

src/test/SDL_test_common.c

@@ -908,6 +908,12 @@ static void SDLTest_PrintPixelFormat(char *text, size_t maxlen, Uint32 format)
     case SDL_PIXELFORMAT_INDEX1MSB:
         SDL_snprintfcat(text, maxlen, "Index1MSB");
         break;
+    case SDL_PIXELFORMAT_INDEX2LSB:
+        SDL_snprintfcat(text, maxlen, "Index2LSB");
+        break;
+    case SDL_PIXELFORMAT_INDEX2MSB:
+        SDL_snprintfcat(text, maxlen, "Index2MSB");
+        break;
     case SDL_PIXELFORMAT_INDEX4LSB:
         SDL_snprintfcat(text, maxlen, "Index4LSB");
         break;

src/video/SDL_pixels.c

@@ -89,6 +89,8 @@ const char *SDL_GetPixelFormatName(Uint32 format)
 
         CASE(SDL_PIXELFORMAT_INDEX1LSB)
         CASE(SDL_PIXELFORMAT_INDEX1MSB)
+        CASE(SDL_PIXELFORMAT_INDEX2LSB)
+        CASE(SDL_PIXELFORMAT_INDEX2MSB)
         CASE(SDL_PIXELFORMAT_INDEX4LSB)
         CASE(SDL_PIXELFORMAT_INDEX4MSB)
         CASE(SDL_PIXELFORMAT_INDEX8)
@@ -309,6 +311,9 @@ Uint32 SDL_GetPixelFormatEnumForMasks(int bpp, Uint32 Rmask, Uint32 Gmask, Uint3
     case 1:
         /* SDL defaults to MSB ordering */
         return SDL_PIXELFORMAT_INDEX1MSB;
+    case 2:
+        /* SDL defaults to MSB ordering */
+        return SDL_PIXELFORMAT_INDEX2MSB;
     case 4:
         /* SDL defaults to MSB ordering */
         return SDL_PIXELFORMAT_INDEX4MSB;

test/testautomation_pixels.c

@@ -11,6 +11,8 @@
 static const Uint32 g_AllFormats[] = {
     SDL_PIXELFORMAT_INDEX1LSB,
     SDL_PIXELFORMAT_INDEX1MSB,
+    SDL_PIXELFORMAT_INDEX2LSB,
+    SDL_PIXELFORMAT_INDEX2MSB,
     SDL_PIXELFORMAT_INDEX4LSB,
     SDL_PIXELFORMAT_INDEX4MSB,
     SDL_PIXELFORMAT_INDEX8,
@@ -56,6 +58,8 @@ static const int g_numAllFormats = SDL_arraysize(g_AllFormats);
 static const char *g_AllFormatsVerbose[] = {
     "SDL_PIXELFORMAT_INDEX1LSB",
     "SDL_PIXELFORMAT_INDEX1MSB",
+    "SDL_PIXELFORMAT_INDEX2LSB",
+    "SDL_PIXELFORMAT_INDEX2MSB",
     "SDL_PIXELFORMAT_INDEX4LSB",
     "SDL_PIXELFORMAT_INDEX4MSB",
     "SDL_PIXELFORMAT_INDEX8",

test/testautomation_surface.c

@@ -660,6 +660,34 @@ static int surface_testOverflow(void *arg)
                         surface != NULL ? "(success)" : SDL_GetError());
     SDL_DestroySurface(surface);
 
+    /* SDL_PIXELFORMAT_INDEX2* needs 1 byte per 4 pixels. */
+    surface = SDL_CreateSurfaceFrom(buf, 12, 1, 3, SDL_PIXELFORMAT_INDEX2LSB);
+    SDLTest_AssertCheck(surface != NULL, "12px * 2 bits per px fits in 3 bytes: %s",
+                        surface != NULL ? "(success)" : SDL_GetError());
+    SDL_DestroySurface(surface);
+    surface = SDL_CreateSurfaceFrom(buf, 12, 1, 3, SDL_PIXELFORMAT_INDEX2MSB);
+    SDLTest_AssertCheck(surface != NULL, "12px * 2 bits per px fits in 3 bytes: %s",
+                        surface != NULL ? "(success)" : SDL_GetError());
+    SDL_DestroySurface(surface);
+
+    surface = SDL_CreateSurfaceFrom(buf, 13, 1, 3, SDL_PIXELFORMAT_INDEX2LSB);
+    SDLTest_AssertCheck(surface == NULL, "Should detect pitch < width * bpp (%d)", surface ? surface->pitch : 0);
+    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
+                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
+    surface = SDL_CreateSurfaceFrom(buf, 13, 1, 3, SDL_PIXELFORMAT_INDEX2MSB);
+    SDLTest_AssertCheck(surface == NULL, "Should detect pitch < width * bpp");
+    SDLTest_AssertCheck(SDL_strcmp(SDL_GetError(), expectedError) == 0,
+                        "Expected \"%s\", got \"%s\"", expectedError, SDL_GetError());
+
+    surface = SDL_CreateSurfaceFrom(buf, 13, 1, 4, SDL_PIXELFORMAT_INDEX2LSB);
+    SDLTest_AssertCheck(surface != NULL, "13px * 2 bits per px fits in 4 bytes: %s",
+                        surface != NULL ? "(success)" : SDL_GetError());
+    SDL_DestroySurface(surface);
+    surface = SDL_CreateSurfaceFrom(buf, 13, 1, 4, SDL_PIXELFORMAT_INDEX2MSB);
+    SDLTest_AssertCheck(surface != NULL, "13px * 2 bits per px fits in 4 bytes: %s",
+                        surface != NULL ? "(success)" : SDL_GetError());
+    SDL_DestroySurface(surface);
+
     /* SDL_PIXELFORMAT_INDEX1* needs 1 byte per 8 pixels. */
     surface = SDL_CreateSurfaceFrom(buf, 16, 1, 2, SDL_PIXELFORMAT_INDEX1LSB);
     SDLTest_AssertCheck(surface != NULL, "16px * 1 bit per px fits in 2 bytes: %s",