Initial commit

source/Graphics/ImageLoader.cpp

@@ -0,0 +1,130 @@
+
+#include <Spectre/System/File.h>
+#include <Spectre/System/Log.h>
+#include <Spectre/Graphics/Image.h>
+#include "ImageLoader.h"
+
+// Disable some file formats that we don't use.
+#define STBI_NO_PSD
+#define STBI_NO_PIC
+#define STBI_NO_GIF
+#define STBI_NO_HDR
+#define STBI_NO_PNM
+
+#define STB_IMAGE_IMPLEMENTATION
+#include "stb_image.h"
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#include "stb_image_write.h"
+
+#include <string.h>
+#include <stdio.h>
+#include <vector>
+
+bool ImageLoader::loadFromFile(const char *filename, Image& img)
+{
+	FILE *fd = fopen(filename, "rb");
+
+	if (fd) {
+		std::vector<unsigned char> buf;
+		fseek(fd, 0, SEEK_END);
+		buf.resize(ftell(fd));
+		rewind(fd);
+		fread(&buf[0], 1, buf.size(), fd);
+		fclose(fd);
+
+		// loaded into memory. now decode.
+		if (decode((const char*)&buf[0], buf.size(), img) == false) {
+			log("ImageLoader: could not load file '%s'. Reason: %s", 
+				filename, m_error);
+			return false;
+		}
+		return true;
+	}
+
+	log("ImageLoader: could not open file '%s'. Reason: %s",
+		filename, std::strerror(errno));
+	return false;
+}
+
+bool ImageLoader::loadFromMemory(const void *data, unsigned size, Image& img)
+{
+	//std::vector<unsigned char> buf;
+
+	//buf.assign(((unsigned char*) data), ((unsigned char*) data) + size); 
+
+	return decode((const char*) data, size, img);
+}
+
+// TODO: Support more formats.
+bool ImageLoader::saveToFile(const Image& img, const char *filename)
+{
+	std::string ext = File::getExtension(filename);
+	std::vector<unsigned char> encoded_data;
+
+	if (ext == "png") {
+
+		if (!encodePNG(img, encoded_data)) {
+			log("ImageLoader: failed to save file '%s'. Reason: \n", 
+				filename, m_error);
+		}
+
+	} else {
+		log("ImageLoader: Invalid file format\n");
+		return false;
+	}
+
+	if (encoded_data.size() > 0) {
+
+		FILE *fd = fopen(filename, "wb");
+		if (fd) {
+			fwrite(&encoded_data[0], 1, encoded_data.size(), fd);
+			fclose(fd);
+		}
+		return true;
+	}
+
+	return false;
+}
+
+
+bool ImageLoader::decode(const char *data, unsigned int size, Image& img)
+{
+	// width, height, num components.
+	int w, h, n_comp;
+	const stbi_uc *ptr = (const stbi_uc *) data;
+
+	unsigned char *pixels = stbi_load_from_memory(ptr, size, &w, &h, &n_comp, 4);
+
+	if (pixels) {
+
+		unsigned int len = w * h * 4;
+
+		img.create(w, h, pixels);
+
+		stbi_image_free(pixels);
+
+		return true;
+	}
+
+	m_error = stbi_failure_reason();
+	return false;
+}
+
+bool ImageLoader::encodePNG(const Image& img, std::vector<unsigned char>& data)
+{
+	int buf_len;
+	unsigned char *raw = (unsigned char*) img.getPixels();
+	unsigned char *buf;
+
+	buf = stbi_write_png_to_mem(raw, img.getStride(), img.getWidth(), img.getHeight(), img.getBpp() / 8, &buf_len);
+	if (buf && buf_len > 0) {
+		
+		data.resize(buf_len);
+		std::memcpy(&data[0], buf, buf_len);
+		STBIW_FREE(buf);
+
+		return true;
+	}
+	m_error = stbi_failure_reason();
+	return false;
+}