Thaugdahl/image additions

dependencies/subprojects/animationwindow/include/Image.h

@@ -1,28 +1,91 @@
 #pragma once
 
-#include <string>
+#include <vector>
 #include "Point.h"
+#include "Color.h"
 #include <filesystem>
 #include "SDL_render.h"
 
 namespace TDT4102 {
+
+    struct ImageCache;
+
     struct Image {
         // Allow the texture to be read out and drawn despite being private
         friend class AnimationWindow;
+        friend class ImageCache;
 
     public:
         explicit Image();
         explicit Image(std::filesystem::path pathToImageFile);
+
+        Image &operator=(Image &&other) {
+            this->~Image();
+
+            state = other.state;
+            texture = other.texture;
+            surface = other.surface;
+
+            other.reset();
+
+            return *this;
+        }
+
+        Image(Image &&other)
+            : texture{other.texture}, surface{other.surface}, path{std::move(other.path)}, state{other.state}
+            {
+            other.reset();
+        }
+
         ~Image();
 
+        /// Creates an image instance from a vector of colors.
+        /// \see TDT4102::Image::bytes
+        static Image fromPixels(const std::vector<TDT4102::Color> &bytes,
+                               int imageWidth, int imageHeight);
+
+        static std::vector<TDT4102::Color> loadPixels(std::filesystem::path pathToImageFile);
+
         int width = 0;
         int height = 0;
+
+        std::vector<TDT4102::Color> getPixels();
+        void setPixels(const std::vector<TDT4102::Color> &, int width_, int height_);
+
     private:
 
+        enum class ImageState {
+            Loaded,
+            FromFile,
+            FromBuffer,
+            Invalidated
+        };
+
         SDL_Texture *texture = nullptr;
-        std::filesystem::path src = "non existent file";
+
+        /// Trade-off. Allows image manipulation at the cost of memory.
+        SDL_Surface *surface = nullptr;
+
+        std::filesystem::path path{"nonexistent"};
+
+        /// The state of the image
+        ImageState state = ImageState::Invalidated;
 
         void load(SDL_Renderer* renderer);
-        void draw(SDL_Renderer* renderer, TDT4102::Point location, int imageWidth = 0, int imageHeight = 0);
+        void draw(SDL_Renderer* renderer, TDT4102::Point location,
+                  int imageWidth = 0, int imageHeight = 0);
+
+        /// Does conditional texture cleanup.
+        /// Unsets the associated texture pointer
+        void cleanupTexture();
+
+        /// Conditionally cleans up the SDL_Surface
+        /// Unsets the associated SDL_Surface pointer
+        void cleanupSurface();
+
+        /// Resets the Image. For use with move-operators
+        void reset();
+
+        static ImageCache cache;
     };
 }

dependencies/subprojects/animationwindow/src/Image.cpp

@@ -1,27 +1,149 @@
 #include "Image.h"
+#include "SDL_surface.h"
 #include <SDL_image.h>
+#include <unordered_set>
+#include <cstring>
+
+namespace TDT4102 {
+/// A caching mechanism to avoid processing images loaded from files
+    struct ImageCache {
+        /// Two-way lookup
+        std::unordered_map<std::filesystem::path, std::pair<SDL_Surface *, SDL_Texture *>> pathToTexture;
+        std::unordered_set<SDL_Texture *> textureMembershipSet;
+        std::unordered_set<SDL_Surface *> surfaceMembershipSet;
+
+        /// Loads an SDL_Texture from the file path and caches it
+        SDL_Texture *insert(SDL_Renderer *renderer, SDL_Surface *surface, const std::filesystem::path &filePath);
+
+        SDL_Texture *getTexture(const std::filesystem::path &path) const;
+        SDL_Surface *getSurface(const std::filesystem::path &path) const;
+
+        bool isTextureCached(SDL_Texture *texture) const;
+        bool isSurfaceCached(SDL_Surface *texture) const;
+
+        ~ImageCache();
+
+    private:
+        ImageCache() = default;
+        friend class Image;
+    };
+}
+
+constexpr uint32_t GetPixelFormat() {
+    return SDL_PIXELFORMAT_ARGB8888;
+}
 
 TDT4102::Image::Image() {}
 
 TDT4102::Image::Image(const std::filesystem::path pathToImageFile) {
-    src = pathToImageFile;
+    path = pathToImageFile;
+
+    SDL_Surface *cachedSurface = cache.getSurface(pathToImageFile);
+
+    if ( cachedSurface == nullptr ) {
+
+        if ( ! std::filesystem::exists(path) ) {
+            throw std::runtime_error("The image file located at " + path.string() + "\ncould not be found");
+        }
+
+        surface = IMG_Load(pathToImageFile.c_str());
+        surface = SDL_ConvertSurfaceFormat(surface, GetPixelFormat(), 0);
+        width = surface->w;
+        height = surface->h;
+    } else {
+        surface = cachedSurface;
+        width = surface->w;
+        height = surface->h;
+    }
+
+    state = ImageState::FromFile;
 }
 
 void TDT4102::Image::load(SDL_Renderer* renderer) {
-    if(!std::filesystem::exists(src)) {
-        throw std::runtime_error("The image file located at: " + src.string() + "\ncould not be found.");
+    // We need a reference to SDL_Renderer to perform the loading operation
+    // This requires loading it once it gets used
+    if ( state == ImageState::FromFile ) {
+        texture = cache.insert(renderer, surface, path);
+        state = texture ? ImageState::Loaded : ImageState::Invalidated;
+    } else if ( state == ImageState::FromBuffer ) {
+        texture = SDL_CreateTextureFromSurface(renderer, surface);
+        state = texture ? ImageState::Loaded : ImageState::Invalidated;
+    }
+}
+
+TDT4102::Image TDT4102::Image::fromPixels(const std::vector<TDT4102::Color> &pixels, int imageWidth, int imageHeight)
+{
+    TDT4102::Image result = TDT4102::Image{};
+    result.setPixels(pixels, imageWidth, imageHeight);
+    result.state = ImageState::FromBuffer;
+    return result;
+}
+
+std::vector<TDT4102::Color> TDT4102::Image::getPixels() {
+
+    std::vector<TDT4102::Color> result;
+    result.resize(width * height);
+
+    // Convert the pixel format before copying
+    if ( surface->format->format != GetPixelFormat()) {
+        SDL_Surface *oldSurface = surface;
+        SDL_Surface *newSurface = SDL_ConvertSurfaceFormat(oldSurface, GetPixelFormat(), 0);
+
+        if ( newSurface != nullptr ) {
+            SDL_FreeSurface(oldSurface);
+            surface = newSurface;
+        }
+    }
+
+    // Early return if we're left with no surface to pull pixels from
+    if ( surface == nullptr ) {
+        return result;
+    }
+
+    // Respect pitch
+    unsigned char *pixels = static_cast<unsigned char *>(surface->pixels);
+    int pitch = surface->pitch;
+
+    for ( int y = 0; y < height; y++ ) {
+        std::memcpy(&result[y*width], &pixels[y*pitch], sizeof(TDT4102::Color)*width);
+    }
+    return result;
+}
+
+void TDT4102::Image::setPixels(const std::vector<TDT4102::Color> &pixels, int width_, int height_) {
+
+    width = width_;
+    height = height_;
+
+    cleanupTexture();
+    cleanupSurface();
+
+    surface = SDL_CreateRGBSurfaceWithFormat(0, width, height, 32, GetPixelFormat());
+
+    if ( surface == nullptr ) {
+        throw std::runtime_error{"Failed to create SDL Surface when setting pixels"};
+        state = ImageState::Invalidated;
+        return;
     }
-    texture = IMG_LoadTexture(renderer, src.string().c_str());
 
-    if(width == 0 && height == 0) {
-        SDL_QueryTexture(texture, nullptr, nullptr, &width, &height);
+    unsigned char *pixelData = static_cast<unsigned char *>(surface->pixels);
+    int pitch = surface->pitch;
+
+    for ( int y = 0; y < height; y++ ) {
+        std::memcpy(
+            &pixelData[y*pitch],
+            &pixels[y*width],
+            width * sizeof(TDT4102::Color)
+        );
     }
+
+    // Invalidate the image. Reload texture
+    state = ImageState::FromBuffer;
 }
 
+
 void TDT4102::Image::draw(SDL_Renderer *renderer, TDT4102::Point location, int imageWidth, int imageHeight) {
-    // We need a reference to SDL_Renderer to perform the loading operation
-    // This requires loading it once it gets used
-    if(texture == nullptr) {
+    if ( texture == nullptr ) {
         load(renderer);
     }
 
@@ -36,8 +158,72 @@ void TDT4102::Image::draw(SDL_Renderer *renderer, TDT4102::Point location, int i
 }
 
 TDT4102::Image::~Image() {
-    if (texture != nullptr) {
+    cleanupTexture();
+    cleanupSurface();
+}
+
+void TDT4102::Image::cleanupTexture() {
+    if (texture != nullptr && ! cache.isTextureCached(texture)) {
         SDL_DestroyTexture(texture);
-        texture = nullptr;
+    }
+    texture = nullptr;
+}
+
+void TDT4102::Image::cleanupSurface() {
+    if ( surface != nullptr && !cache.isSurfaceCached(surface)) {
+        SDL_FreeSurface(surface);
+    }
+    surface = nullptr;
+}
+
+void TDT4102::Image::reset() {
+    state = ImageState::Invalidated;
+    texture = nullptr;
+    surface = nullptr;
+}
+
+
+TDT4102::ImageCache TDT4102::Image::cache = TDT4102::ImageCache{};
+
+SDL_Texture *TDT4102::ImageCache::insert(SDL_Renderer *renderer, SDL_Surface *surface, const std::filesystem::path &filePath) {
+    // TODO: Normalize cache key
+    if ( pathToTexture.contains(filePath) ) {
+        return pathToTexture[filePath].second;
+    } else {
+        SDL_Texture *texture = SDL_CreateTextureFromSurface(renderer, surface);
+        pathToTexture.insert(std::make_pair(filePath, std::make_pair(surface, texture)));
+        textureMembershipSet.insert(texture);
+        surfaceMembershipSet.insert(surface);
+        return texture;
+    }
+}
+
+bool TDT4102::ImageCache::isTextureCached(SDL_Texture *texture) const {
+    return textureMembershipSet.contains(texture);
+}
+
+bool TDT4102::ImageCache::isSurfaceCached(SDL_Surface *surface) const {
+    return surfaceMembershipSet.contains(surface);
+}
+
+
+SDL_Surface *TDT4102::ImageCache::getSurface(const std::filesystem::path &path) const {
+    if ( pathToTexture.contains(path) ) {
+        return pathToTexture[path].first;
+    }
+    return nullptr;
+}
+
+SDL_Texture *TDT4102::ImageCache::getTexture(const std::filesystem::path &path) const {
+    if ( pathToTexture.contains(path) ) {
+        return pathToTexture[path].second;
+    }
+    return nullptr;
+}
+
+TDT4102::ImageCache::~ImageCache() {
+    for ( auto &[key, value] : pathToTexture ) {
+        SDL_FreeSurface(value.first);
+        SDL_DestroyTexture(value.second);
     }
 }