Added support for textures with palettes

Closes libsdl-org#6192

Author: slouken

include/SDL3/SDL_render.h

@@ -660,6 +660,7 @@ extern SDL_DECLSPEC SDL_Texture * SDLCALL SDL_CreateTextureFromSurface(SDL_Rende
  *   pixels, required
  * - `SDL_PROP_TEXTURE_CREATE_HEIGHT_NUMBER`: the height of the texture in
  *   pixels, required
+ * - `SDL_PROP_TEXTURE_CREATE_PALETTE_POINTER`: an SDL_Palette to use with the texture, optional.
  * - `SDL_PROP_TEXTURE_CREATE_SDR_WHITE_POINT_FLOAT`: for HDR10 and floating
  *   point textures, this defines the value of 100% diffuse white, with higher
  *   values being displayed in the High Dynamic Range headroom. This defaults
@@ -759,6 +760,7 @@ extern SDL_DECLSPEC SDL_Texture * SDLCALL SDL_CreateTextureWithProperties(SDL_Re
 #define SDL_PROP_TEXTURE_CREATE_ACCESS_NUMBER               "SDL.texture.create.access"
 #define SDL_PROP_TEXTURE_CREATE_WIDTH_NUMBER                "SDL.texture.create.width"
 #define SDL_PROP_TEXTURE_CREATE_HEIGHT_NUMBER               "SDL.texture.create.height"
+#define SDL_PROP_TEXTURE_CREATE_PALETTE_POINTER             "SDL.texture.create.palette"
 #define SDL_PROP_TEXTURE_CREATE_SDR_WHITE_POINT_FLOAT       "SDL.texture.create.SDR_white_point"
 #define SDL_PROP_TEXTURE_CREATE_HDR_HEADROOM_FLOAT          "SDL.texture.create.HDR_headroom"
 #define SDL_PROP_TEXTURE_CREATE_D3D11_TEXTURE_POINTER       "SDL.texture.create.d3d11.texture"
@@ -929,6 +931,40 @@ extern SDL_DECLSPEC SDL_Renderer * SDLCALL SDL_GetRendererFromTexture(SDL_Textur
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_GetTextureSize(SDL_Texture *texture, float *w, float *h);
 
+/**
+ * Set the palette used by a texture.
+ *
+ * A single palette can be shared with many textures.
+ *
+ * \param texture the texture to update.
+ * \param palette the SDL_Palette structure to use.
+ * \returns true on success or false on failure; call SDL_GetError() for more
+ *          information.
+ *
+ * \threadsafety This function should only be called on the main thread.
+ *
+ * \since This function is available since SDL 3.4.0.
+ *
+ * \sa SDL_CreatePalette
+ * \sa SDL_GetTexturePalette
+ */
+extern SDL_DECLSPEC bool SDLCALL SDL_SetTexturePalette(SDL_Texture *texture, SDL_Palette *palette);
+
+/**
+ * Get the palette used by a texture.
+ *
+ * \param texture the texture to query.
+ * \returns a pointer to the palette used by the texture, or NULL if there is
+ *          no palette used.
+ *
+ * \threadsafety This function should only be called on the main thread.
+ *
+ * \since This function is available since SDL 3.4.0.
+ *
+ * \sa SDL_SetTexturePalette
+ */
+extern SDL_DECLSPEC SDL_Palette * SDLCALL SDL_GetTexturePalette(SDL_Texture *texture);
+
 /**
  * Set an additional color value multiplied into render copy operations.
  *
@@ -1155,7 +1191,7 @@ extern SDL_DECLSPEC bool SDLCALL SDL_GetTextureBlendMode(SDL_Texture *texture, S
 /**
  * Set the scale mode used for texture scale operations.
  *
- * The default texture scale mode is SDL_SCALEMODE_LINEAR.
+ * The default texture scale mode is SDL_SCALEMODE_LINEAR for RGB and YUV textures and SDL_SCALEMODE_PIXELART for indexed textures.
  *
  * If the scale mode is not supported, the closest supported mode is chosen.
  *

src/dynapi/SDL_dynapi.sym

@@ -1257,6 +1257,8 @@ SDL3_0.0.0 {
     SDL_hid_get_properties;
     SDL_GetPixelFormatFromGPUTextureFormat;
     SDL_GetGPUTextureFormatFromPixelFormat;
+    SDL_SetTexturePalette;
+    SDL_GetTexturePalette;
     # extra symbols go here (don't modify this line)
   local: *;
 };

src/dynapi/SDL_dynapi_overrides.h

@@ -1283,3 +1283,5 @@
 #define SDL_GetPixelFormatFromGPUTextureFormat SDL_GetPixelFormatFromGPUTextureFormat_REAL
 #define SDL_GetGPUTextureFormatFromPixelFormat SDL_GetGPUTextureFormatFromPixelFormat_REAL
 #define JNI_OnLoad JNI_OnLoad_REAL
+#define SDL_SetTexturePalette SDL_SetTexturePalette_REAL
+#define SDL_GetTexturePalette SDL_GetTexturePalette_REAL

src/dynapi/SDL_dynapi_procs.h

@@ -1291,3 +1291,5 @@ SDL_DYNAPI_PROC(SDL_PropertiesID,SDL_hid_get_properties,(SDL_hid_device *a),(a),
 SDL_DYNAPI_PROC(SDL_PixelFormat,SDL_GetPixelFormatFromGPUTextureFormat,(SDL_GPUTextureFormat a),(a),return)
 SDL_DYNAPI_PROC(SDL_GPUTextureFormat,SDL_GetGPUTextureFormatFromPixelFormat,(SDL_PixelFormat a),(a),return)
 SDL_DYNAPI_PROC(Sint32,JNI_OnLoad,(JavaVM *a, void *b),(a,b),return)
+SDL_DYNAPI_PROC(bool,SDL_SetTexturePalette,(SDL_Texture *a,SDL_Palette *b),(a,b),return)
+SDL_DYNAPI_PROC(SDL_Palette*,SDL_GetTexturePalette,(SDL_Texture *a),(a),return)