Merged r3007:3008 from branches/SDL-1.2: MapRGB/MapRGBA const correctness.

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%402299

include/SDL_video.h

@@ -1300,15 +1300,16 @@ extern DECLSPEC void SDLCALL SDL_DestroyRenderer(SDL_WindowID windowID);
 /*
  * Maps an RGB triple to an opaque pixel value for a given pixel format
  */
-extern DECLSPEC Uint32 SDLCALL SDL_MapRGB
-    (SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b);
+extern DECLSPEC Uint32 SDLCALL SDL_MapRGB(const SDL_PixelFormat * const format,
+                                          const Uint8 r, const Uint8 g,
+                                          const Uint8 b);
 
 /*
  * Maps an RGBA quadruple to a pixel value for a given pixel format
  */
-extern DECLSPEC Uint32 SDLCALL SDL_MapRGBA(SDL_PixelFormat * format,
-                                           Uint8 r, Uint8 g, Uint8 b,
-                                           Uint8 a);
+extern DECLSPEC Uint32 SDLCALL SDL_MapRGBA(const SDL_PixelFormat * const fmt,
+                                           const Uint8 r, const Uint8 g,
+                                           const Uint8 b, const Uint8 a);
 
 /*
  * Maps a pixel value into the RGB components for a given pixel format

src/video/SDL_pixels.c

@@ -537,7 +537,8 @@ SDL_FindColor(SDL_Palette * pal, Uint8 r, Uint8 g, Uint8 b)
 
 /* Find the opaque pixel value corresponding to an RGB triple */
 Uint32
-SDL_MapRGB(SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b)
+SDL_MapRGB(const SDL_PixelFormat * const format, const Uint8 r, const Uint8 g,
+           const Uint8 b)
 {
     if (format->palette == NULL) {
         return (r >> format->Rloss) << format->Rshift
@@ -550,7 +551,8 @@ SDL_MapRGB(SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b)
 
 /* Find the pixel value corresponding to an RGBA quadruple */
 Uint32
-SDL_MapRGBA(SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
+SDL_MapRGBA(const SDL_PixelFormat * const format, const Uint8 r, const Uint8 g,
+            const Uint8 b, const Uint8 a)
 {
     if (format->palette == NULL) {
         return (r >> format->Rloss) << format->Rshift