Adjust code to develop + change place in code where alpha is applied

client/gui/CAnimation.cpp

@@ -94,8 +94,8 @@ public:
 	// Keep the original palette, in order to do color switching operation
 	void savePalette();
 
-	void draw(SDL_Surface * where, int posX=0, int posY=0, const Rect *src=nullptr, ui8 alpha=255) override;
-	void draw(SDL_Surface * where, const SDL_Rect * dest, const SDL_Rect * src, ui8 alpha=255) override;
+	void draw(SDL_Surface * where, int posX=0, int posY=0, const Rect *src=nullptr) const override;
+	void draw(SDL_Surface * where, const SDL_Rect * dest, const SDL_Rect * src) const override;
 	std::shared_ptr<IImage> scaleFast(float scale) const override;
 	void exportBitmap(const boost::filesystem::path & path) const override;
 	void playerColored(PlayerColor player) override;
@@ -642,17 +642,16 @@ SDLImage::SDLImage(std::string filename)
 	}
 }
 
-void SDLImage::draw(SDL_Surface *where, int posX, int posY, const Rect *src, ui8 alpha)
+void SDLImage::draw(SDL_Surface *where, int posX, int posY, const Rect *src) const
 {
 	if(!surf)
 		return;
 
 	Rect destRect(posX, posY, surf->w, surf->h);
-
-	draw(where, &destRect, src, alpha);
+	draw(where, &destRect, src);
 }
 
-void SDLImage::draw(SDL_Surface* where, const SDL_Rect* dest, const SDL_Rect* src, ui8 alpha)
+void SDLImage::draw(SDL_Surface* where, const SDL_Rect* dest, const SDL_Rect* src) const
 {
 	if (!surf)
 		return;
@@ -663,12 +662,6 @@ void SDLImage::draw(SDL_Surface* where, const SDL_Rect* dest, const SDL_Rect* sr
 
 	if(src)
 	{
-		if(alpha != UINT8_MAX)
-		{
-			const ColorShifterMultiplyAndAdd alphaShifter ({255, 255, 255, alpha}, {0, 0, 0, 0});
-			adjustPalette(&alphaShifter);
-		}
-
 		if(src->x < margins.x)
 			destShift.x += margins.x - src->x;
 

client/gui/CAnimation.h

@@ -40,8 +40,8 @@ public:
 	using SpecialPalette = std::array<SDL_Color, 7>;
 
 	//draws image on surface "where" at position
-	virtual void draw(SDL_Surface * where, int posX = 0, int posY = 0, const Rect * src = nullptr, ui8 alpha = 255) = 0;
-	virtual void draw(SDL_Surface * where, const SDL_Rect * dest, const SDL_Rect * src, ui8 alpha = 255) = 0;
+	virtual void draw(SDL_Surface * where, int posX = 0, int posY = 0, const Rect * src = nullptr) const = 0;
+	virtual void draw(SDL_Surface * where, const SDL_Rect * dest, const SDL_Rect * src) const = 0;
 
 	virtual std::shared_ptr<IImage> scaleFast(float scale) const = 0;
 

client/gui/Canvas.cpp

@@ -70,12 +70,12 @@ void Canvas::draw(std::shared_ptr<IImage> image, const Point & pos, const Rect &
 		image->draw(surface, renderOffset.x + pos.x, renderOffset.y + pos.y, &sourceRect);
 }
 
-void Canvas::draw(std::shared_ptr<IImage> image, const Point & pos, const Rect & sourceRect, uint8_t alpha)
-{
-	assert(image);
-	if (image)
-		image->draw(surface, renderOffset.x + pos.x, renderOffset.y + pos.y, &sourceRect, alpha);
-}
+//void Canvas::draw(std::shared_ptr<IImage> image, const Point & pos, const Rect & sourceRect, uint8_t alpha)
+//{
+//	assert(image);
+//	if (image)
+//		image->draw(surface, renderOffset.x + pos.x, renderOffset.y + pos.y, &sourceRect, alpha);
+//}
 
 void Canvas::draw(Canvas & image, const Point & pos)
 {

client/gui/Canvas.h

@@ -52,7 +52,8 @@ public:
 	void draw(std::shared_ptr<IImage> image, const Point & pos, const Rect & sourceRect);
 
 	/// renders section of image bounded by sourceRect at specified position at specific transparency value
-	void draw(std::shared_ptr<IImage> image, const Point & pos, const Rect & sourceRect, uint8_t alpha);
+	/// disabled for now as never used in code with alpha support
+//	void draw(std::shared_ptr<IImage> image, const Point & pos, const Rect & sourceRect, uint8_t alpha);
 
 
 	/// renders another canvas onto this canvas

client/widgets/Images.cpp

@@ -16,6 +16,7 @@
 #include "../gui/SDL_Pixels.h"
 #include "../gui/CGuiHandler.h"
 #include "../gui/CCursorHandler.h"
+#include "../gui/ColorFilter.h"
 
 #include "../battle/BattleInterface.h"
 #include "../battle/BattleInterfaceClasses.h"
@@ -454,7 +455,15 @@ void CShowableAnim::blitImage(size_t frame, size_t group, SDL_Surface *to)
 	Rect src( xOffset, yOffset, pos.w, pos.h);
 	auto img = anim->getImage(frame, group);
 	if(img)
-		img->draw(to, pos.x, pos.y, &src, alpha);
+	{
+		if(alpha != UINT8_MAX)
+		{
+			const ColorFilter alphaFilter = ColorFilter::genAlphaShifter(vstd::lerp(0.0f, 1.0f, alpha/255.0f));
+			img->adjustPalette(alphaFilter);
+		}
+
+		img->draw(to, pos.x, pos.y, &src);
+	}
 }
 
 void CShowableAnim::rotate(bool on, bool vertical)

client/widgets/Images.h

@@ -142,7 +142,7 @@ public:
 	//Set per-surface alpha, 0 = transparent, 255 = opaque
 	void setAlpha(ui32 alphaValue);
 
-	CShowableAnim(int x, int y, std::string name, ui8 flags=0, ui32 Delay=4, size_t Group=0, uint8_t alpha = 255);
+	CShowableAnim(int x, int y, std::string name, ui8 flags=0, ui32 Delay=4, size_t Group=0, uint8_t alpha = UINT8_MAX);
 	~CShowableAnim();
 
 	//set animation to group or part of group