Merge pull request #5916 from Laserlicht/generate_overlay_shadow

Generate overlay & shadow

client/render/ImageLocator.cpp

@@ -25,6 +25,12 @@ SharedImageLocator::SharedImageLocator(const JsonNode & config, EImageBlitMode m
 
 	if(!config["defFile"].isNull())
 		defFile = AnimationPath::fromJson(config["defFile"]);
+
+	if(!config["generateShadow"].isNull())
+		generateShadow = static_cast<SharedImageLocator::ShadowMode>(config["generateShadow"].Integer());
+
+	if(!config["generateOverlay"].isNull())
+		generateOverlay = static_cast<SharedImageLocator::OverlayMode>(config["generateOverlay"].Integer());
 }
 
 SharedImageLocator::SharedImageLocator(const ImagePath & path, EImageBlitMode mode)
@@ -60,6 +66,10 @@ bool SharedImageLocator::operator < (const SharedImageLocator & other) const
 		return defFrame < other.defFrame;
 	if(layer != other.layer)
 		return layer < other.layer;
+	if(generateShadow != other.generateShadow)
+		return generateShadow < other.generateShadow;
+	if(generateOverlay != other.generateOverlay)
+		return generateOverlay < other.generateOverlay;
 
 	return false;
 }

client/render/ImageLocator.h

@@ -16,12 +16,28 @@
 
 struct SharedImageLocator
 {
+	enum class ShadowMode
+	{
+		SHADOW_NONE,
+		SHADOW_NORMAL,
+		SHADOW_SHEAR
+	};
+	enum class OverlayMode
+	{
+		OVERLAY_NONE,
+		OVERLAY_OUTLINE,
+		OVERLAY_FLAG
+	};
+
 	std::optional<ImagePath> image;
 	std::optional<AnimationPath> defFile;
 	int defFrame = -1;
 	int defGroup = -1;
 	EImageBlitMode layer = EImageBlitMode::OPAQUE;
 
+	std::optional<ShadowMode> generateShadow;
+	std::optional<OverlayMode> generateOverlay;
+
 	SharedImageLocator() = default;
 	SharedImageLocator(const AnimationPath & path, int frame, int group, EImageBlitMode layer);
 	SharedImageLocator(const JsonNode & config, EImageBlitMode layer);

client/renderSDL/RenderHandler.cpp

@@ -291,9 +291,15 @@ std::shared_ptr<SDLImageShared> RenderHandler::loadScaledImage(const ImageLocato
 
 	std::string imagePathString = pathToLoad.getName();
 
-	if(locator.layer == EImageBlitMode::ONLY_FLAG_COLOR || locator.layer == EImageBlitMode::ONLY_SELECTION)
+	bool generateShadow = locator.generateShadow && (*locator.generateShadow) != SharedImageLocator::ShadowMode::SHADOW_NONE;
+	bool generateOverlay = locator.generateOverlay && (*locator.generateOverlay) != SharedImageLocator::OverlayMode::OVERLAY_NONE;
+	bool isShadow = locator.layer == EImageBlitMode::ONLY_SHADOW_HIDE_SELECTION || locator.layer == EImageBlitMode::ONLY_SHADOW_HIDE_FLAG_COLOR;
+	bool isOverlay = locator.layer == EImageBlitMode::ONLY_FLAG_COLOR || locator.layer == EImageBlitMode::ONLY_SELECTION;
+	bool optimizeImage = !(isShadow && generateShadow) && !(isOverlay && generateOverlay); // images needs to expanded
+
+	if(isOverlay && !generateOverlay)
 		imagePathString += "-OVERLAY";
-	if(locator.layer == EImageBlitMode::ONLY_SHADOW_HIDE_SELECTION || locator.layer == EImageBlitMode::ONLY_SHADOW_HIDE_FLAG_COLOR)
+	if(isShadow && !generateShadow)
 		imagePathString += "-SHADOW";
 	if(locator.playerColored.isValidPlayer())
 		imagePathString += "-" + boost::to_upper_copy(GameConstants::PLAYER_COLOR_NAMES[locator.playerColored.getNum()]);
@@ -304,16 +310,26 @@ std::shared_ptr<SDLImageShared> RenderHandler::loadScaledImage(const ImageLocato
 	auto imagePathSprites = ImagePath::builtin(imagePathString).addPrefix(scaledSpritesPath.at(locator.scalingFactor));
 	auto imagePathData = ImagePath::builtin(imagePathString).addPrefix(scaledDataPath.at(locator.scalingFactor));
 
+	std::shared_ptr<SDLImageShared> img = nullptr;
+
 	if(CResourceHandler::get()->existsResource(imagePathSprites) && (settings["video"]["useHdTextures"].Bool() || locator.scalingFactor == 1))
-		return std::make_shared<SDLImageShared>(imagePathSprites);
+		img = std::make_shared<SDLImageShared>(imagePathSprites, optimizeImage);
+	else if(CResourceHandler::get()->existsResource(imagePathData) && (settings["video"]["useHdTextures"].Bool() || locator.scalingFactor == 1))
+		img = std::make_shared<SDLImageShared>(imagePathData, optimizeImage);
+	else if(CResourceHandler::get()->existsResource(imagePath))
+		img = std::make_shared<SDLImageShared>(imagePath, optimizeImage);
 
-	if(CResourceHandler::get()->existsResource(imagePathData) && (settings["video"]["useHdTextures"].Bool() || locator.scalingFactor == 1))
-		return std::make_shared<SDLImageShared>(imagePathData);
+	if(img)
+	{
+		// TODO: Performance improvement - Run algorithm on optimized ("trimmed") images
+		// Not implemented yet because different frame image sizes seems to cause wobbeling shadow -> needs a way around this
+		if(isShadow && generateShadow)
+			img = img->drawShadow((*locator.generateShadow) == SharedImageLocator::ShadowMode::SHADOW_SHEAR);
+		if(isOverlay && generateOverlay && (*locator.generateOverlay) == SharedImageLocator::OverlayMode::OVERLAY_OUTLINE)
+			img = img->drawOutline(Colors::WHITE, 1);
+	}
 
-	if(CResourceHandler::get()->existsResource(imagePath))
-		return std::make_shared<SDLImageShared>(imagePath);
-
-	return nullptr;
+	return img;
 }
 
 std::shared_ptr<IImage> RenderHandler::loadImage(const ImageLocator & locator)

client/renderSDL/SDLImage.cpp

@@ -70,7 +70,7 @@ SDLImageShared::SDLImageShared(SDL_Surface * from)
 	fullSize.y = surf->h;
 }
 
-SDLImageShared::SDLImageShared(const ImagePath & filename)
+SDLImageShared::SDLImageShared(const ImagePath & filename, bool optimizeImage)
 	: surf(nullptr),
 	margins(0, 0),
 	fullSize(0, 0),
@@ -89,7 +89,8 @@ SDLImageShared::SDLImageShared(const ImagePath & filename)
 		fullSize.x = surf->w;
 		fullSize.y = surf->h;
 
-		optimizeSurface();
+		if(optimizeImage)
+			optimizeSurface();
 	}
 }
 
@@ -429,6 +430,49 @@ std::shared_ptr<const ISharedImage> SDLImageShared::verticalFlip() const
 	return ret;
 }
 
+std::shared_ptr<SDLImageShared> SDLImageShared::drawShadow(bool doSheer) const
+{
+	if(upscalingInProgress)
+		throw std::runtime_error("Attempt to access images that is still being loaded!");
+
+	if (!surf)
+		return nullptr;
+
+	SDL_Surface * shadow = CSDL_Ext::drawShadow(surf, doSheer);
+	auto ret = std::make_shared<SDLImageShared>(shadow);
+	ret->fullSize = fullSize;
+	ret->margins.x = margins.x;
+	ret->margins.y = margins.y;
+	ret->optimizeSurface();
+
+	// erase our own reference
+	SDL_FreeSurface(shadow);
+
+	return ret;
+}
+
+std::shared_ptr<SDLImageShared> SDLImageShared::drawOutline(const ColorRGBA & color, int thickness) const
+{
+	if(upscalingInProgress)
+		throw std::runtime_error("Attempt to access images that is still being loaded!");
+
+	if (!surf)
+		return nullptr;
+
+	SDL_Color sdlColor = { color.r, color.g, color.b, color.a };
+	SDL_Surface * outline = CSDL_Ext::drawOutline(surf, sdlColor, thickness);
+	auto ret = std::make_shared<SDLImageShared>(outline);
+	ret->fullSize = fullSize;
+	ret->margins.x = margins.x;
+	ret->margins.y = margins.y;
+	ret->optimizeSurface();
+
+	// erase our own reference
+	SDL_FreeSurface(outline);
+
+	return ret;
+}
+
 // Keep the original palette, in order to do color switching operation
 void SDLImageShared::savePalette()
 {

client/renderSDL/SDLImage.h

@@ -46,7 +46,7 @@ public:
 	//Load image from def file
 	SDLImageShared(const CDefFile *data, size_t frame, size_t group=0);
 	//Load from bitmap file
-	SDLImageShared(const ImagePath & filename);
+	SDLImageShared(const ImagePath & filename, bool optimizeImage=true);
 	//Create using existing surface, extraRef will increase refcount on SDL_Surface
 	SDLImageShared(SDL_Surface * from);
 	~SDLImageShared();
@@ -71,5 +71,8 @@ public:
 	[[nodiscard]] std::shared_ptr<const ISharedImage> scaleInteger(int factor, SDL_Palette * palette, EImageBlitMode blitMode) const override;
 	[[nodiscard]] std::shared_ptr<const ISharedImage> scaleTo(const Point & size, SDL_Palette * palette) const override;
 
+	std::shared_ptr<SDLImageShared> drawShadow(bool doSheer) const;
+	std::shared_ptr<SDLImageShared> drawOutline(const ColorRGBA & color, int thickness) const;
+
 	friend class SDLImageLoader;
 };

client/renderSDL/SDL_Extensions.cpp

@@ -23,6 +23,7 @@
 #include "../../lib/GameConstants.h"
 
 #include <tbb/parallel_for.h>
+#include <tbb/parallel_reduce.h>
 
 #include <SDL_render.h>
 #include <SDL_surface.h>
@@ -685,3 +686,299 @@ void CSDL_Ext::getClipRect(SDL_Surface * src, Rect & other)
 
 	other = CSDL_Ext::fromSDL(rect);
 }
+
+SDL_Surface* CSDL_Ext::drawOutline(SDL_Surface* sourceSurface, const SDL_Color& color, int thickness)
+{
+	if(thickness < 1)
+		return nullptr;
+
+	SDL_Surface* destSurface = newSurface(Point(sourceSurface->w, sourceSurface->h));
+
+	if(SDL_MUSTLOCK(sourceSurface)) SDL_LockSurface(sourceSurface);
+	if(SDL_MUSTLOCK(destSurface)) SDL_LockSurface(destSurface);
+
+	int width = sourceSurface->w;
+	int height = sourceSurface->h;
+
+	// Helper lambda to get alpha
+	auto getAlpha = [&](int x, int y) -> Uint8 {
+		if (x < 0 || x >= width || y < 0 || y >= height)
+			return 0;
+		Uint32 pixel = *((Uint32*)sourceSurface->pixels + y * width + x);
+		Uint8 r;
+		Uint8 g;
+		Uint8 b;
+		Uint8 a;
+		SDL_GetRGBA(pixel, sourceSurface->format, &r, &g, &b, &a);
+		return a;
+	};
+
+	tbb::parallel_for(tbb::blocked_range<size_t>(0, height), [&](const tbb::blocked_range<size_t>& r)
+	{
+		for (int y = r.begin(); y != r.end(); ++y)
+		{
+			for (int x = 0; x < width; x++)
+			{
+				Uint8 alpha = getAlpha(x, y);
+				if (alpha != 0)
+					continue; // Skip opaque or semi-transparent pixels
+
+				Uint8 maxNearbyAlpha = 0;
+
+				for (int dy = -thickness; dy <= thickness; ++dy)
+				{
+					for (int dx = -thickness; dx <= thickness; ++dx)
+					{
+						if (dx * dx + dy * dy > thickness * thickness)
+							continue; // circular area
+
+						int nx = x + dx;
+						int ny = y + dy;
+						if (nx < 0 || ny < 0 || nx >= width || ny >= height)
+							continue;
+
+						Uint8 neighborAlpha = getAlpha(nx, ny);
+						if (neighborAlpha > maxNearbyAlpha)
+							maxNearbyAlpha = neighborAlpha;
+					}
+				}
+
+				if (maxNearbyAlpha > 0)
+				{
+					Uint8 finalAlpha = maxNearbyAlpha - alpha; // alpha is 0 here, so effectively maxNearbyAlpha
+					Uint32 newPixel = SDL_MapRGBA(destSurface->format, color.r, color.g, color.b, finalAlpha);
+					*((Uint32*)destSurface->pixels + y * width + x) = newPixel;
+				}
+			}
+		}
+	});
+
+	if(SDL_MUSTLOCK(sourceSurface)) SDL_UnlockSurface(sourceSurface);
+	if(SDL_MUSTLOCK(destSurface)) SDL_UnlockSurface(destSurface);
+
+	return destSurface;
+}
+
+void applyAffineTransform(SDL_Surface* src, SDL_Surface* dst, double a, double b, double c, double d, double tx, double ty)
+{
+	// Check if the transform is purely scaling (and optionally translation)
+	bool isPureScaling = vstd::isAlmostZero(b) && vstd::isAlmostZero(c);
+
+	if (isPureScaling)
+	{
+		// Calculate target dimensions
+		int scaledW = static_cast<int>(src->w * a);
+		int scaledH = static_cast<int>(src->h * d);
+
+		SDL_Rect srcRect = { 0, 0, src->w, src->h };
+		SDL_Rect dstRect = { static_cast<int>(tx), static_cast<int>(ty), scaledW, scaledH };
+
+		// Convert surfaces to same format if needed
+		if (src->format->format != dst->format->format)
+		{
+			SDL_Surface* converted = SDL_ConvertSurface(src, dst->format, 0);
+			if (!converted)
+				throw std::runtime_error("SDL_ConvertSurface failed!");
+
+			SDL_BlitScaled(converted, &srcRect, dst, &dstRect);
+			SDL_FreeSurface(converted);
+		}
+		else
+			SDL_BlitScaled(src, &srcRect, dst, &dstRect);
+
+		return;
+	}
+
+	// Lock surfaces for direct pixel access
+	if (SDL_MUSTLOCK(src)) SDL_LockSurface(src);
+	if (SDL_MUSTLOCK(dst)) SDL_LockSurface(dst);
+
+	// Calculate inverse matrix M_inv for mapping dst -> src
+	double det = a * d - b * c;
+	if (vstd::isAlmostZero(det))
+		throw std::runtime_error("Singular transform matrix!");
+	double invDet = 1.0 / det;
+	double ia =  d * invDet;
+	double ib = -b * invDet;
+	double ic = -c * invDet;
+	double id =  a * invDet;
+
+	auto srcPixels = (Uint32*)src->pixels;
+	auto dstPixels = (Uint32*)dst->pixels;
+
+	tbb::parallel_for(tbb::blocked_range<size_t>(0, dst->h), [&](const tbb::blocked_range<size_t>& r)
+	{
+		// For each pixel in the destination image
+		for(int y = r.begin(); y != r.end(); ++y)
+		{
+			for(int x = 0; x < dst->w; x++)
+			{
+				// Map destination pixel (x,y) back to source coordinates (srcX, srcY)
+				double srcX = ia * (x - tx) + ib * (y - ty);
+				double srcY = ic * (x - tx) + id * (y - ty);
+
+				// Nearest neighbor sampling (can be improved to bilinear)
+				auto srcXi = static_cast<int>(round(srcX));
+				auto srcYi = static_cast<int>(round(srcY));
+
+				// Check bounds
+				if (srcXi >= 0 && srcXi < src->w && srcYi >= 0 && srcYi < src->h)
+				{
+					Uint32 pixel = srcPixels[srcYi * src->w + srcXi];
+					dstPixels[y * dst->w + x] = pixel;
+				}
+				else
+					dstPixels[y * dst->w + x] = 0x00000000;  // transparent black
+			}
+		}
+	});
+
+	if (SDL_MUSTLOCK(src)) SDL_UnlockSurface(src);
+	if (SDL_MUSTLOCK(dst)) SDL_UnlockSurface(dst);
+}
+
+int getLowestNonTransparentY(SDL_Surface* surface)
+{
+	if (SDL_MUSTLOCK(surface)) SDL_LockSurface(surface);
+
+	const int w = surface->w;
+	const int h = surface->h;
+	const int bpp = surface->format->BytesPerPixel;
+	auto pixels = static_cast<Uint8*>(surface->pixels);
+
+	// Use parallel_reduce to find the max y with non-transparent pixel
+	int lowestY = tbb::parallel_reduce(
+		tbb::blocked_range<int>(0, h),
+		-1,  // initial lowestY = -1 (fully transparent)
+		[&](const tbb::blocked_range<int>& r, int localMaxY) -> int
+		{
+			for (int y = r.begin(); y != r.end(); ++y)
+			{
+				Uint8* row = pixels + y * surface->pitch;
+				for (int x = 0; x < w; ++x)
+				{
+					Uint32 pixel = *(Uint32*)(row + x * bpp);
+					Uint8 a = (pixel >> 24) & 0xFF; // Fast path for ARGB8888
+					if (a > 0)
+					{
+						localMaxY = std::max(localMaxY, y);
+						break; // no need to scan rest of row
+					}
+				}
+			}
+			return localMaxY;
+		},
+		[](int a, int b) -> int
+		{
+			return std::max(a, b);
+		}
+	);
+
+	if (SDL_MUSTLOCK(surface)) SDL_UnlockSurface(surface);
+	return lowestY;
+}
+
+void fillAlphaPixelWithRGBA(SDL_Surface* surface, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
+{
+	if (SDL_MUSTLOCK(surface)) SDL_LockSurface(surface);
+
+	auto pixels = (Uint32*)surface->pixels;
+	int pixelCount = surface->w * surface->h;
+
+	tbb::parallel_for(tbb::blocked_range<size_t>(0, pixelCount), [&](const tbb::blocked_range<size_t>& range)
+	{
+		for(int i = range.begin(); i != range.end(); ++i)
+		{
+			Uint32 pixel = pixels[i];
+			Uint8 pr;
+			Uint8 pg;
+			Uint8 pb;
+			Uint8 pa;
+			// Extract existing RGBA components using SDL_GetRGBA
+			SDL_GetRGBA(pixel, surface->format, &pr, &pg, &pb, &pa);
+
+			Uint32 newPixel = SDL_MapRGBA(surface->format, r, g, b, a);
+			if(pa < 128)
+				newPixel = SDL_MapRGBA(surface->format, 0, 0, 0, 0);
+
+			pixels[i] = newPixel;
+		}
+	});
+
+	if (SDL_MUSTLOCK(surface)) SDL_UnlockSurface(surface);
+}
+
+void boxBlur(SDL_Surface* surface)
+{
+	if (SDL_MUSTLOCK(surface)) SDL_LockSurface(surface);
+
+	int width = surface->w;
+	int height = surface->h;
+	int pixelCount = width * height;
+
+	Uint32* pixels = static_cast<Uint32*>(surface->pixels);
+	std::vector<Uint32> temp(pixelCount);
+
+	tbb::parallel_for(0, height, [&](int y)
+	{
+		for (int x = 0; x < width; ++x)
+		{
+			int sumR = 0;
+			int sumG = 0;
+			int sumB = 0;
+			int sumA = 0;
+			int count = 0;
+
+			for (int ky = -1; ky <= 1; ++ky)
+			{
+				int ny = std::clamp(y + ky, 0, height - 1);
+				for (int kx = -1; kx <= 1; ++kx)
+				{
+					int nx = std::clamp(x + kx, 0, width - 1);
+					Uint32 pixel = pixels[ny * width + nx];
+
+					sumA += (pixel >> 24) & 0xFF;
+					sumR += (pixel >> 16) & 0xFF;
+					sumG += (pixel >> 8)  & 0xFF;
+					sumB += (pixel >> 0)  & 0xFF;
+					++count;
+				}
+			}
+
+			Uint8 a = sumA / count;
+			Uint8 r = sumR / count;
+			Uint8 g = sumG / count;
+			Uint8 b = sumB / count;
+			temp[y * width + x] = (a << 24) | (r << 16) | (g << 8) | b;
+		}
+	});
+
+	std::copy(temp.begin(), temp.end(), pixels);
+
+	if (SDL_MUSTLOCK(surface)) SDL_UnlockSurface(surface);
+}
+
+SDL_Surface * CSDL_Ext::drawShadow(SDL_Surface * sourceSurface, bool doSheer)
+{
+	SDL_Surface *destSurface = newSurface(Point(sourceSurface->w, sourceSurface->h));
+
+	double shearX = doSheer ? 0.5 : 0.0;
+	double scaleY = doSheer ? 0.5 : 0.25;
+
+	int lowestSource = getLowestNonTransparentY(sourceSurface);
+	int lowestTransformed = lowestSource * scaleY;
+
+	// Parameters for applyAffineTransform
+	double a = 1.0;
+	double b = shearX;
+	double c = 0.0;
+	double d = scaleY;
+	double tx = -shearX * lowestSource;
+	double ty = lowestSource - lowestTransformed;
+
+	applyAffineTransform(sourceSurface, destSurface, a, b, c, d, tx, ty);
+	fillAlphaPixelWithRGBA(destSurface, 0, 0, 0, 128);
+	boxBlur(destSurface);
+
+	return destSurface;
+}

client/renderSDL/SDL_Extensions.h

@@ -76,4 +76,7 @@ SDL_Color toSDL(const ColorRGBA & color);
 	void setDefaultColorKey(SDL_Surface * surface);
 	///set key-color to 0,255,255 only if it exactly mapped
 	void setDefaultColorKeyPresize(SDL_Surface * surface);
+
+	SDL_Surface * drawOutline(SDL_Surface * source, const SDL_Color & color, int thickness);
+	SDL_Surface * drawShadow(SDL_Surface * source, bool doSheer);
 }

client/renderSDL/ScalableImage.cpp

@@ -440,6 +440,8 @@ std::shared_ptr<const ISharedImage> ScalableImageShared::loadOrGenerateImage(EIm
 
 	loadingLocator.image = locator.image;
 	loadingLocator.defFile = locator.defFile;
+	loadingLocator.generateShadow = locator.generateShadow;
+	loadingLocator.generateOverlay = locator.generateOverlay;
 	loadingLocator.defFrame = locator.defFrame;
 	loadingLocator.defGroup = locator.defGroup;
 	loadingLocator.layer = mode;

docs/modders/Animation_Format.md

@@ -45,7 +45,13 @@ VCMI allows overriding HoMM3 .def files with .json replacement. Compared to .def
             "frame" : 0,
 
             // Filename for this frame
-            "file" : "filename.png"
+            "file" : "filename.png",
+
+            // Automatically create shadow for this frame if required. Optional, 0 = None, 1 = Normal Shadow, 2 = Sheared Shadow (e.g. for adventure map)
+            "generateShadow" : 1,
+
+            // Automatically create overlay for this frame if required. Optional, 0 = None, 1 = Outline
+            "generateOverlay" : 1,
         }.
         ...
     ]