Codechange: Allow for using a sprite encoder that is not the currently active blitter when loading a sprite.

src/blitter/base.hpp

@@ -25,7 +25,7 @@ enum BlitterMode {
 /**
  * How all blitters should look like. Extend this class to make your own.
  */
-class Blitter {
+class Blitter : public SpriteEncoder {
 public:
 	/** Parameters related to blitting. */
 	struct BlitterParams {
@@ -58,6 +58,11 @@ public:
 	 */
 	virtual uint8 GetScreenDepth() = 0;
 
+	bool Is32BppSupported() override
+	{
+		return this->GetScreenDepth() > 8;
+	}
+
 	/**
 	 * Draw an image to the screen, given an amount of params defined above.
 	 */
@@ -74,11 +79,6 @@ public:
 	 */
 	virtual void DrawColourMappingRect(void *dst, int width, int height, PaletteID pal) = 0;
 
-	/**
-	 * Convert a sprite from the loader to our own format.
-	 */
-	virtual Sprite *Encode(const SpriteLoader::Sprite *sprite, AllocatorProc *allocator) = 0;
-
 	/**
 	 * Move the destination pointer the requested amount x and y, keeping in mind
 	 *  any pitch and bpp of the renderer.

src/spritecache.cpp

@@ -404,10 +404,14 @@ static void *ReadRecolourSprite(uint16 file_slot, uint num)
  * @param id          Sprite number.
  * @param sprite_type Type of sprite.
  * @param allocator   Allocator function to use.
+ * @param encoder     Sprite encoder to use.
  * @return Read sprite data.
  */
-static void *ReadSprite(const SpriteCache *sc, SpriteID id, SpriteType sprite_type, AllocatorProc *allocator)
+static void *ReadSprite(const SpriteCache *sc, SpriteID id, SpriteType sprite_type, AllocatorProc *allocator, SpriteEncoder *encoder)
 {
+	/* Use current blitter if no other sprite encoder is given. */
+	if (encoder == nullptr) encoder = BlitterFactory::GetCurrentBlitter();
+
 	uint8 file_slot = sc->file_slot;
 	size_t file_pos = sc->file_pos;
 
@@ -422,7 +426,7 @@ static void *ReadSprite(const SpriteCache *sc, SpriteID id, SpriteType sprite_ty
 	sprite[ZOOM_LVL_NORMAL].type = sprite_type;
 
 	SpriteLoaderGrf sprite_loader(sc->container_ver);
-	if (sprite_type != ST_MAPGEN && BlitterFactory::GetCurrentBlitter()->GetScreenDepth() == 32) {
+	if (sprite_type != ST_MAPGEN && encoder->Is32BppSupported()) {
 		/* Try for 32bpp sprites first. */
 		sprite_avail = sprite_loader.LoadSprite(sprite, file_slot, file_pos, sprite_type, true);
 	}
@@ -433,7 +437,7 @@ static void *ReadSprite(const SpriteCache *sc, SpriteID id, SpriteType sprite_ty
 	if (sprite_avail == 0) {
 		if (sprite_type == ST_MAPGEN) return nullptr;
 		if (id == SPR_IMG_QUERY) usererror("Okay... something went horribly wrong. I couldn't load the fallback sprite. What should I do?");
-		return (void*)GetRawSprite(SPR_IMG_QUERY, ST_NORMAL, allocator);
+		return (void*)GetRawSprite(SPR_IMG_QUERY, ST_NORMAL, allocator, encoder);
 	}
 
 	if (sprite_type == ST_MAPGEN) {
@@ -466,7 +470,7 @@ static void *ReadSprite(const SpriteCache *sc, SpriteID id, SpriteType sprite_ty
 
 	if (!ResizeSprites(sprite, sprite_avail, file_slot, sc->id)) {
 		if (id == SPR_IMG_QUERY) usererror("Okay... something went horribly wrong. I couldn't resize the fallback sprite. What should I do?");
-		return (void*)GetRawSprite(SPR_IMG_QUERY, ST_NORMAL, allocator);
+		return (void*)GetRawSprite(SPR_IMG_QUERY, ST_NORMAL, allocator, encoder);
 	}
 
 	if (sprite->type == ST_FONT && ZOOM_LVL_FONT != ZOOM_LVL_NORMAL) {
@@ -478,7 +482,7 @@ static void *ReadSprite(const SpriteCache *sc, SpriteID id, SpriteType sprite_ty
 		sprite[ZOOM_LVL_NORMAL].data   = sprite[ZOOM_LVL_FONT].data;
 	}
 
-	return BlitterFactory::GetCurrentBlitter()->Encode(sprite, allocator);
+	return encoder->Encode(sprite, allocator);
 }
 
 
@@ -845,9 +849,10 @@ static void *HandleInvalidSpriteRequest(SpriteID sprite, SpriteType requested, S
  * @param sprite Sprite to read.
  * @param type Expected sprite type.
  * @param allocator Allocator function to use. Set to nullptr to use the usual sprite cache.
+ * @param encoder Sprite encoder to use. Set to nullptr to use the currently active blitter.
  * @return Sprite raw data
  */
-void *GetRawSprite(SpriteID sprite, SpriteType type, AllocatorProc *allocator)
+void *GetRawSprite(SpriteID sprite, SpriteType type, AllocatorProc *allocator, SpriteEncoder *encoder)
 {
 	assert(type != ST_MAPGEN || IsMapgenSpriteID(sprite));
 	assert(type < ST_INVALID);
@@ -863,19 +868,19 @@ void *GetRawSprite(SpriteID sprite, SpriteType type, AllocatorProc *allocator)
 
 	if (sc->type != type) return HandleInvalidSpriteRequest(sprite, type, sc, allocator);
 
-	if (allocator == nullptr) {
+	if (allocator == nullptr && encoder == nullptr) {
 		/* Load sprite into/from spritecache */
 
 		/* Update LRU */
 		sc->lru = ++_sprite_lru_counter;
 
 		/* Load the sprite, if it is not loaded, yet */
-		if (sc->ptr == nullptr) sc->ptr = ReadSprite(sc, sprite, type, AllocSprite);
+		if (sc->ptr == nullptr) sc->ptr = ReadSprite(sc, sprite, type, AllocSprite, nullptr);
 
 		return sc->ptr;
 	} else {
 		/* Do not use the spritecache, but a different allocator. */
-		return ReadSprite(sc, sprite, type, allocator);
+		return ReadSprite(sc, sprite, type, allocator, encoder);
 	}
 }
 

src/spritecache.h

@@ -11,6 +11,7 @@
 #define SPRITECACHE_H
 
 #include "gfx_type.h"
+#include "spriteloader/spriteloader.hpp"
 
 /** Data structure describing a sprite. */
 struct Sprite {
@@ -25,7 +26,7 @@ extern uint _sprite_cache_size;
 
 typedef void *AllocatorProc(size_t size);
 
-void *GetRawSprite(SpriteID sprite, SpriteType type, AllocatorProc *allocator = nullptr);
+void *GetRawSprite(SpriteID sprite, SpriteType type, AllocatorProc *allocator = nullptr, SpriteEncoder *encoder = nullptr);
 bool SpriteExists(SpriteID sprite);
 
 SpriteType GetSpriteType(SpriteID sprite);

src/spriteloader/spriteloader.hpp

@@ -13,6 +13,9 @@
 #include "../core/alloc_type.hpp"
 #include "../gfx_type.h"
 
+struct Sprite;
+typedef void *AllocatorProc(size_t size);
+
 /** Interface for the loader of our sprites. */
 class SpriteLoader {
 public:
@@ -64,4 +67,20 @@ public:
 	virtual ~SpriteLoader() { }
 };
 
+/** Interface for something that can encode a sprite. */
+class SpriteEncoder {
+public:
+
+	virtual ~SpriteEncoder() { }
+
+	/**
+	 * Can the sprite encoder make use of RGBA sprites?
+	 */
+	virtual bool Is32BppSupported() = 0;
+
+	/**
+	 * Convert a sprite from the loader to our own format.
+	 */
+	virtual Sprite *Encode(const SpriteLoader::Sprite *sprite, AllocatorProc *allocator) = 0;
+};
 #endif /* SPRITELOADER_HPP */