Codechange: Give sprite encoders a hint which colour components of a sprite are filled with useful information.

src/fontcache.cpp

@@ -351,6 +351,7 @@ const Sprite *TrueTypeFontCache::GetGlyph(GlyphID key)
 				0,  // x_offs
 				0,  // y_offs
 				ST_FONT,
+				SCC_PAL,
 				builtin_questionmark_data
 			};
 
@@ -614,6 +615,7 @@ const Sprite *FreeTypeFontCache::InternalGetGlyph(GlyphID key, bool aa)
 	SpriteLoader::Sprite sprite;
 	sprite.AllocateData(ZOOM_LVL_NORMAL, width * height);
 	sprite.type = ST_FONT;
+	sprite.colours = (aa ? SCC_PAL | SCC_ALPHA : SCC_PAL);
 	sprite.width = width;
 	sprite.height = height;
 	sprite.x_offs = slot->bitmap_left;
@@ -676,7 +678,6 @@ const void *FreeTypeFontCache::InternalGetFontTable(uint32 tag, size_t &length)
 	length = len;
 	return result;
 }
-
 #endif /* WITH_FREETYPE */
 
 

src/os/macosx/font_osx.cpp

@@ -286,6 +286,7 @@ const Sprite *CoreTextFontCache::InternalGetGlyph(GlyphID key, bool use_aa)
 	SpriteLoader::Sprite sprite;
 	sprite.AllocateData(ZOOM_LVL_NORMAL, width * height);
 	sprite.type = ST_FONT;
+	sprite.colours = (use_aa ? SCC_PAL | SCC_ALPHA : SCC_PAL);
 	sprite.width = width;
 	sprite.height = height;
 	sprite.x_offs = (int16)std::round(CGRectGetMinX(bounds));

src/os/windows/font_win32.cpp

@@ -495,6 +495,7 @@ void Win32FontCache::ClearFontCache()
 	SpriteLoader::Sprite sprite;
 	sprite.AllocateData(ZOOM_LVL_NORMAL, width * height);
 	sprite.type = ST_FONT;
+	sprite.colours = (aa ? SCC_PAL | SCC_ALPHA : SCC_PAL);
 	sprite.width = width;
 	sprite.height = height;
 	sprite.x_offs = gm.gmptGlyphOrigin.x;

src/spritecache.cpp

@@ -199,6 +199,7 @@ static bool ResizeSpriteIn(SpriteLoader::Sprite *sprite, ZoomLevel src, ZoomLeve
 	sprite[tgt].height = sprite[src].height * scaled_1;
 	sprite[tgt].x_offs = sprite[src].x_offs * scaled_1;
 	sprite[tgt].y_offs = sprite[src].y_offs * scaled_1;
+	sprite[tgt].colours = sprite[src].colours;
 
 	sprite[tgt].AllocateData(tgt, sprite[tgt].width * sprite[tgt].height);
 
@@ -221,6 +222,7 @@ static void ResizeSpriteOut(SpriteLoader::Sprite *sprite, ZoomLevel zoom)
 	sprite[zoom].height = UnScaleByZoom(sprite[ZOOM_LVL_NORMAL].height, zoom);
 	sprite[zoom].x_offs = UnScaleByZoom(sprite[ZOOM_LVL_NORMAL].x_offs, zoom);
 	sprite[zoom].y_offs = UnScaleByZoom(sprite[ZOOM_LVL_NORMAL].y_offs, zoom);
+	sprite[zoom].colours = sprite[ZOOM_LVL_NORMAL].colours;
 
 	sprite[zoom].AllocateData(zoom, sprite[zoom].height * sprite[zoom].width);
 
@@ -487,6 +489,7 @@ static void *ReadSprite(const SpriteCache *sc, SpriteID id, SpriteType sprite_ty
 		sprite[ZOOM_LVL_NORMAL].x_offs = sprite[ZOOM_LVL_FONT].x_offs;
 		sprite[ZOOM_LVL_NORMAL].y_offs = sprite[ZOOM_LVL_FONT].y_offs;
 		sprite[ZOOM_LVL_NORMAL].data   = sprite[ZOOM_LVL_FONT].data;
+		sprite[ZOOM_LVL_NORMAL].colours = sprite[ZOOM_LVL_FONT].colours;
 	}
 
 	return encoder->Encode(sprite, allocator);

src/spriteloader/grf.cpp

@@ -23,15 +23,6 @@
 
 extern const byte _palmap_w2d[];
 
-/** The different colour components a sprite can have. */
-enum SpriteColourComponent {
-	SCC_RGB   = 1 << 0, ///< Sprite has RGB.
-	SCC_ALPHA = 1 << 1, ///< Sprite has alpha.
-	SCC_PAL   = 1 << 2, ///< Sprite has palette data.
-	SCC_MASK  = SCC_RGB | SCC_ALPHA | SCC_PAL, ///< Mask of valid colour bits.
-};
-DECLARE_ENUM_AS_BIT_SET(SpriteColourComponent)
-
 /**
  * We found a corrupted sprite. This means that the sprite itself
  * contains invalid data or is too small for the given dimensions.
@@ -234,6 +225,7 @@ uint8 LoadSpriteV1(SpriteLoader::Sprite *sprite, uint8 file_slot, size_t file_po
 	sprite[zoom_lvl].width  = FioReadWord();
 	sprite[zoom_lvl].x_offs = FioReadWord();
 	sprite[zoom_lvl].y_offs = FioReadWord();
+	sprite[zoom_lvl].colours = SCC_PAL;
 
 	if (sprite[zoom_lvl].width > INT16_MAX) {
 		WarnCorruptSprite(file_slot, file_pos, __LINE__);
@@ -302,6 +294,8 @@ uint8 LoadSpriteV2(SpriteLoader::Sprite *sprite, uint8 file_slot, size_t file_po
 			if (colour & SCC_ALPHA) bpp++;    // Has alpha data.
 			if (colour & SCC_PAL)   bpp++;    // Has palette data.
 
+			sprite[zoom_lvl].colours = (SpriteColourComponent)colour;
+
 			/* For chunked encoding we store the decompressed size in the file,
 			 * otherwise we can calculate it from the image dimensions. */
 			uint decomp_size = (type & 0x08) ? FioReadDword() : sprite[zoom_lvl].width * sprite[zoom_lvl].height * bpp;

src/spriteloader/spriteloader.hpp

@@ -11,11 +11,21 @@
 #define SPRITELOADER_HPP
 
 #include "../core/alloc_type.hpp"
+#include "../core/enum_type.hpp"
 #include "../gfx_type.h"
 
 struct Sprite;
 typedef void *AllocatorProc(size_t size);
 
+/** The different colour components a sprite can have. */
+enum SpriteColourComponent {
+	SCC_RGB   = 1 << 0, ///< Sprite has RGB.
+	SCC_ALPHA = 1 << 1, ///< Sprite has alpha.
+	SCC_PAL   = 1 << 2, ///< Sprite has palette data.
+	SCC_MASK  = SCC_RGB | SCC_ALPHA | SCC_PAL, ///< Mask of valid colour bits.
+};
+DECLARE_ENUM_AS_BIT_SET(SpriteColourComponent)
+
 /** Interface for the loader of our sprites. */
 class SpriteLoader {
 public:
@@ -40,6 +50,7 @@ public:
 		int16 x_offs;                    ///< The x-offset of where the sprite will be drawn
 		int16 y_offs;                    ///< The y-offset of where the sprite will be drawn
 		SpriteType type;                 ///< The sprite type
+		SpriteColourComponent colours;   ///< The colour components of the sprite with useful information.
 		SpriteLoader::CommonPixel *data; ///< The sprite itself
 
 		/**