Remove unused SDL_TextureModulate enum

Fixes https://github.com/libsdl-org/SDL/issues/6387

include/SDL3/SDL_render.h

@@ -115,16 +115,6 @@ typedef enum
     SDL_TEXTUREACCESS_TARGET     /**< Texture can be used as a render target */
 } SDL_TextureAccess;
 
-/**
- * The texture channel modulation used in SDL_RenderTexture().
- */
-typedef enum
-{
-    SDL_TEXTUREMODULATE_NONE = 0x00000000,     /**< No modulation */
-    SDL_TEXTUREMODULATE_COLOR = 0x00000001,    /**< srcC = srcC * color */
-    SDL_TEXTUREMODULATE_ALPHA = 0x00000002     /**< srcA = srcA * alpha */
-} SDL_TextureModulate;
-
 /**
  * Flip constants for SDL_RenderTextureRotated
  */

src/render/SDL_render.c

@@ -1408,11 +1408,6 @@ int SDL_SetTextureColorMod(SDL_Texture *texture, Uint8 r, Uint8 g, Uint8 b)
 {
     CHECK_TEXTURE_MAGIC(texture, -1);
 
-    if (r < 255 || g < 255 || b < 255) {
-        texture->modMode |= SDL_TEXTUREMODULATE_COLOR;
-    } else {
-        texture->modMode &= ~SDL_TEXTUREMODULATE_COLOR;
-    }
     texture->color.r = r;
     texture->color.g = g;
     texture->color.b = b;
@@ -1442,11 +1437,6 @@ int SDL_SetTextureAlphaMod(SDL_Texture *texture, Uint8 alpha)
 {
     CHECK_TEXTURE_MAGIC(texture, -1);
 
-    if (alpha < 255) {
-        texture->modMode |= SDL_TEXTUREMODULATE_ALPHA;
-    } else {
-        texture->modMode &= ~SDL_TEXTUREMODULATE_ALPHA;
-    }
     texture->color.a = alpha;
     if (texture->native) {
         return SDL_SetTextureAlphaMod(texture->native, alpha);

src/render/SDL_sysrender.h

@@ -65,7 +65,6 @@ struct SDL_Texture
     int access;                 /**< SDL_TextureAccess */
     int w;                      /**< The width of the texture */
     int h;                      /**< The height of the texture */
-    int modMode;                /**< The texture modulation mode */
     SDL_BlendMode blendMode;    /**< The texture blend mode */
     SDL_ScaleMode scaleMode;    /**< The texture scale mode */
     SDL_Color color;            /**< Texture modulation values */