Blitter: Change some informational virtual functions to member values

src/blitter/32bpp_base.hpp

@@ -18,7 +18,11 @@
 /** Base for all 32bpp blitters. */
 class Blitter_32bppBase : public Blitter {
 public:
-	uint8 GetScreenDepth() override { return 32; }
+	Blitter_32bppBase()
+	{
+		this->SetScreenDepth(32);
+	}
+
 	void *MoveTo(void *video, int x, int y) override;
 	void SetPixel(void *video, int x, int y, uint8 colour) override;
 	void SetPixel32(void *video, int x, int y, uint8 colour, uint32 colour32) override;

src/blitter/8bpp_base.hpp

@@ -15,7 +15,11 @@
 /** Base for all 8bpp blitters. */
 class Blitter_8bppBase : public Blitter {
 public:
-	uint8 GetScreenDepth() override { return 8; }
+	Blitter_8bppBase()
+	{
+		this->SetScreenDepth(8);
+	}
+
 	void DrawColourMappingRect(void *dst, int width, int height, PaletteID pal) override;
 	void *MoveTo(void *video, int x, int y) override;
 	void SetPixel(void *video, int x, int y, uint8 colour) override;

src/blitter/base.hpp

@@ -44,6 +44,15 @@ DECLARE_ENUM_AS_BIT_SET(BlitterSpriteFlags);
  * How all blitters should look like. Extend this class to make your own.
  */
 class Blitter : public SpriteEncoder {
+	uint8 screen_depth = 0;
+
+protected:
+	void SetScreenDepth(uint8 depth)
+	{
+		this->screen_depth = depth;
+		this->SetIs32BppSupported(depth > 8);
+	}
+
 public:
 	/** Parameters related to blitting. */
 	struct BlitterParams {
@@ -75,11 +84,9 @@ public:
 	 * Get the screen depth this blitter works for.
 	 *  This is either: 8, 16, 24 or 32.
 	 */
-	virtual uint8 GetScreenDepth() = 0;
-
-	bool Is32BppSupported() override
+	inline uint8 GetScreenDepth() const
 	{
-		return this->GetScreenDepth() > 8;
+		return this->screen_depth;
 	}
 
 	/**

src/blitter/null.hpp

@@ -15,7 +15,11 @@
 /** Blitter that does nothing. */
 class Blitter_Null : public Blitter {
 public:
-	uint8 GetScreenDepth() override { return 0; }
+	Blitter_Null()
+	{
+		this->SetScreenDepth(0);
+	}
+
 	void Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom) override {};
 	void DrawColourMappingRect(void *dst, int width, int height, PaletteID pal) override {};
 	Sprite *Encode(const SpriteLoader::Sprite *sprite, AllocatorProc *allocator) override;