Added screenshot feature (F2 key)

src/coders/png.cpp

@@ -201,12 +201,12 @@ int _png_write(const char* filename, uint width, uint height, const ubyte* data,
 
 	spng_set_ihdr(ctx, &ihdr);
 	fmt = SPNG_FMT_PNG;
-
-	ret = spng_encode_image(ctx, data, width * height , fmt, SPNG_ENCODE_FINALIZE);
-
+	ret = spng_encode_image(ctx, data, (size_t)width * (size_t)height * pixsize , fmt, SPNG_ENCODE_FINALIZE);
 	if (ret) {
 		printf("spng_encode_image() error: %s\n", spng_strerror(ret));
-		goto encode_error;
+		fflush(stdout);
+		spng_ctx_free(ctx);
+		return ret;
 	}
 
 	size_t png_size;
@@ -218,9 +218,7 @@ int _png_write(const char* filename, uint width, uint height, const ubyte* data,
 	else {
 		files::write_bytes(filename, (const char*)png_buf, png_size);
 	}
-	free(png_buf);
-
-encode_error:
+	fflush(stdout);
 	spng_ctx_free(ctx);
 	return ret;
 }

src/engine.cpp

@@ -13,6 +13,7 @@
 #include "window/Camera.h"
 #include "window/input.h"
 #include "graphics/Batch2D.h"
+#include "graphics/ImageData.h"
 #include "world/World.h"
 #include "world/Level.h"
 #include "voxels/Chunk.h"
@@ -23,8 +24,10 @@
 #include "frontend/world_render.h"
 #include "frontend/hud.h"
 #include "frontend/gui/GUI.h"
+#include "util/platform.h"
 
 #include "coders/json.h"
+#include "coders/png.h"
 #include "files/files.h"
 
 using std::shared_ptr;
@@ -73,6 +76,14 @@ void Engine::updateHotkeys() {
 	if (Events::jpressed(keycode::O)) {
 		occlusion = !occlusion;
 	}
+	if (Events::jpressed(keycode::F2)) {
+		ImageData* image = Window::takeScreenshot();
+		image->flipY();
+		std::string filename = platform::get_screenshot_file("png");
+		png::write_image(filename, image);
+		delete image;
+		std::cout << "saved screenshot as " << filename << std::endl;
+	}
 	if (Events::jpressed(keycode::F3)) {
 		level->player->debug = !level->player->debug;
 	}

src/graphics/ImageData.cpp

@@ -1,6 +1,7 @@
 #include "ImageData.h"
 
 #include <assert.h>
+#include <stdexcept>
 
 inline int min(int a, int b) {
     return (a < b) ? a : b;
@@ -23,7 +24,52 @@ ImageData::~ImageData() {
     }
 }
 
-#include <iostream>
+void ImageData::flipX() {
+    uint size;
+    switch (format) {
+        case ImageFormat::rgb888:
+        case ImageFormat::rgba8888: {
+            size = (format == ImageFormat::rgba8888) ? 4 : 3;
+            ubyte* pixels = (ubyte*)data;
+            for (uint y = 0; y < height; y++) {
+                for (uint x = 0; x < width/2; x++) {
+                    for (uint c = 0; c < size; c++) {
+                        ubyte temp = pixels[(y * width + x) * size + c];
+                        pixels[(y * width + x) * size + c] = pixels[(y * width + (width - x - 1)) * size + c];
+                        pixels[(y * width + (width - x - 1)) * size + c] = temp;
+                    }
+                }
+            }
+            break;
+        }
+        default:
+            throw std::runtime_error("format is not supported");
+    }
+}
+
+void ImageData::flipY() {
+    uint size;
+    switch (format) {
+        case ImageFormat::rgb888:
+        case ImageFormat::rgba8888: {
+            size = (format == ImageFormat::rgba8888) ? 4 : 3;
+            ubyte* pixels = (ubyte*)data;
+            for (uint y = 0; y < height/2; y++) {
+                for (uint x = 0; x < width; x++) {
+                    for (uint c = 0; c < size; c++) {
+                        ubyte temp = pixels[(y * width + x) * size + c];
+                        pixels[(y * width + x) * size + c] = pixels[((height-y-1) * width + x) * size + c];
+                        pixels[((height-y-1) * width + x) * size + c] = temp;
+                    }
+                }
+            }
+            break;
+        }
+        default:
+            throw std::runtime_error("format is not supported");
+    }
+}
+
 ImageData* add_atlas_margins(ImageData* image, int grid_size) {
     // RGBA is only supported
     assert(image->getFormat() == ImageFormat::rgba8888);

src/graphics/ImageData.h

@@ -17,6 +17,9 @@ public:
     ImageData(ImageFormat format, uint width, uint height, void* data);
     ~ImageData();
 
+    void flipX();
+    void flipY();
+
     void* getData() const {
         return data;
     }

src/settings.h

@@ -15,7 +15,7 @@ struct DisplaySettings {
 	/* GLFW swap interval value, 0 - unlimited fps, 1 - vsync*/
 	int swapInterval = 1;
 	/* Window title */
-	const char* title = "VoxelEngine-Cpp v0.13";
+	const char* title = "VoxelEngine-Cpp v0.14";
 };
 
 struct ChunksSettings {

src/util/platform.cpp

@@ -1,12 +1,46 @@
 #include "platform.h"
 
+#include <sstream>
+#include <filesystem>
+#include <iomanip>
+#include <time.h>
+
+#include "../typedefs.h"
+
 #define SETTINGS_FILE "settings.json"
+#define SCREENSHOTS_FOLDER "screenshots"
+
+using std::string;
 
 
-std::string platform::get_settings_file() {
+string platform::get_settings_file() {
 	return SETTINGS_FILE;
 }
 
+string platform::get_screenshot_file(string ext) {
+	std::string folder = SCREENSHOTS_FOLDER;
+	if (!std::filesystem::is_directory(folder)) {
+		std::filesystem::create_directory(folder);
+	}
+
+	auto t = std::time(nullptr);
+    auto tm = *std::localtime(&t);
+
+	const char* format = "%d-%m-%Y_%H-%M-%S";
+
+	std::stringstream ss;
+	ss << std::put_time(&tm, format);
+	string datetimestr = ss.str();
+
+	string filename = folder+"/screenshot-"+datetimestr+"."+ext;
+	uint index = 0;
+	while (std::filesystem::exists(filename)) {
+		filename = folder+"/screenshot-"+datetimestr+"-"+std::to_string(index)+"."+ext;
+		index++;
+	}
+	return filename;
+}
+
 #ifdef WIN32
 #include <Windows.h>
 

src/util/platform.h

@@ -6,6 +6,7 @@
 namespace platform {
     extern void configure_encoding();
     extern std::string get_settings_file();
+    extern std::string get_screenshot_file(std::string ext);
 }
 
 #endif // UTIL_PLATFORM_H_

src/window/Window.cpp

@@ -1,6 +1,7 @@
 #include <iostream>
 #include "Window.h"
 #include "Events.h"
+#include "../graphics/ImageData.h"
 
 #include <GL/glew.h>
 #include <GLFW/glfw3.h>
@@ -181,3 +182,9 @@ void Window::swapBuffers(){
 double Window::time() {
 	return glfwGetTime();
 }
+
+ImageData* Window::takeScreenshot() {
+	ubyte* data = new ubyte[width * height * 3];
+	glReadPixels(0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, data);
+	return new ImageData(ImageFormat::rgb888, width, height, data);
+}

src/window/Window.h

@@ -10,6 +10,7 @@
 #include <glm/glm.hpp>
 
 class GLFWwindow;
+class ImageData;
 
 class Window {
 	static GLFWwindow* window;
@@ -33,8 +34,9 @@ public:
 	static void resetScissor();
 
 	static void clear();
-
 	static double time();
+
+	static ImageData* takeScreenshot();
 };
 
 #endif /* WINDOW_WINDOW_H_ */