xyzimage example

diff.diff

--- xyzcrush.cpp	2018-01-27 02:08:27.431825844 +0100
+++ xyzcrush_new.cpp	2018-01-27 02:03:22.000000000 +0100
@@ -25,6 +25,7 @@
 # include <algorithm>
 #endif
 #include "zopfli/zlib_container.h"
+#include "../../include/xyzimage.h"
 
 # ifdef __MINGW64_VERSION_MAJOR
 int _dowildcard = -1; /* enable wildcard expansion for mingw-w64 */
@@ -73,8 +74,33 @@
 	return s;
 }
 
+ZopfliOptions zopfli_options;
+
+static size_t zopfli_compress_func(void* buffer_in, size_t len_in, void* buffer_out, size_t len_out, xyzimage_error_t* error) {
+	// buffer_in, buffer_out, len_in and len_out verified by caller
+
+	size_t comp_size = 0;
+	unsigned char* comp_data = NULL;
+
+	ZopfliZlibCompress(
+			&zopfli_options, (const unsigned char*)buffer_in, len_in, &comp_data, &comp_size);
+
+	if (comp_size > len_out) {
+		free(comp_data);
+		if (error) {
+			*error = XYZIMAGE_ERROR_BUFFER_TOO_SMALL;
+		}
+		return 0;
+	}
+
+	memcpy(buffer_out, comp_data, comp_size);
+
+	free(comp_data);
+
+	return comp_size;
+}
+
 int main(int argc, char* argv[]) {
-	ZopfliOptions zopfli_options;
 	ZopfliInitOptions(&zopfli_options);
 	zopfli_options.verbose = 0;
 	zopfli_options.verbose_more = 0;
@@ -93,8 +119,7 @@
 	char header[5];
 
 	for (int arg = 1; arg < argc; arg++) {
-		std::ifstream file(argv[arg],
-			std::ios::binary | std::ios::ate);
+		FILE* file = fopen(argv[arg], "rb");
 		if (!file) {
 			std::cerr << "Error reading file " << argv[arg] << "."
 				<< std::endl;
@@ -102,65 +127,49 @@
 			continue;
 		}
 
-		long size = file.tellg();
-		header[4] = '\0';
+		xyzimage_error_t error_code = XYZIMAGE_ERROR_OK;
+		XYZImage* img = xyzimage_fopen(file, &error_code);
 
-		file.seekg(0, std::ios::beg);
-		file.read(header, 4);
+		fclose(file);
 
-		if (memcmp(header, "XYZ1", 4) != 0) {
+		if (error_code != XYZIMAGE_ERROR_OK) {
 			std::cerr << "Input file " << argv[arg]
-				<< " is not an XYZ file: '" << header << "'." << std::endl;
+					  << " is not an XYZ file" << std::endl;
 			errors++;
 			continue;
 		}
 
-		unsigned short width;
-		unsigned short height;
-		file.read((char*) &width, 2);
-		file.read((char*) &height, 2);
-
-		int compressed_xyz_size = size - 8;
-		Bytef* compressed_xyz_data = new Bytef[compressed_xyz_size];
-
-		file.read((char*) compressed_xyz_data, compressed_xyz_size);
-
-		uLongf xyz_size = 768 + (width * height);
-		Bytef* xyz_data = new Bytef[xyz_size];
+		// Compress XYZ data
+		xyzimage_set_compress_func(img, zopfli_compress_func);
 
-		int status = uncompress(xyz_data, &xyz_size, compressed_xyz_data,
-			compressed_xyz_size);
+		std::stringstream ss;
+		ss << GetFilename(argv[arg]) + std::string(".xyz");
+		std::string xyz_filename = ss.str();
 
-		if (status != Z_OK) {
-			std::cerr << "XYZ error in file " << argv[arg] << "." << std::endl;
+		FILE* xyz_file = fopen(xyz_filename.c_str(), "wb");
+		if (!xyz_file) {
+			std::cerr << "Error writing file " << argv[arg] << "."
+					  << std::endl;
 			errors++;
 			continue;
 		}
-		delete[] compressed_xyz_data;
 
-		// Compress XYZ data
-		size_t comp_size = 0;
-		unsigned char* comp_data = 0;
+		xyzimage_fwrite(img, xyz_file, &error_code);
 
-		ZopfliZlibCompress(&zopfli_options, xyz_data, xyz_size, &comp_data,
-			&comp_size);
+		fclose(xyz_file);
 
-		delete[] xyz_data;
+		if (error_code != XYZIMAGE_ERROR_OK) {
+			std::cerr << "Error writing file " << argv[arg] << "."
+					  << std::endl;
+			errors++;
+			continue;
+		}
 
-		std::stringstream ss;
-		ss << GetFilename(argv[arg]) + std::string(".xyz");
-		std::string xyz_filename = ss.str();
-		std::ofstream xyz_file(xyz_filename.c_str(), std::ofstream::binary);
-		xyz_file.write("XYZ1", 4);
-		xyz_file.write(reinterpret_cast<char*>(&width), 2);
-		xyz_file.write(reinterpret_cast<char*>(&height), 2);
-		xyz_file.write(reinterpret_cast<char*>(comp_data), comp_size);
-		xyz_file.close();
-		delete[] comp_data;
+		xyzimage_free(img);
 
-		std::cout << "Input file " << argv[arg] << ": " << size << "->"
+		/*std::cout << "Input file " << argv[arg] << ": " << size << "->"
 			<< comp_size + 8 << " (" << (comp_size + 8) * 100 / size << "%)"
-			<< std::endl;
+			<< std::endl;*/
 	}
 
 	if (errors > 0) {

main.c

#include <stdio.h>

#include "xyzimage.h"

int main() {
	xyzimage_error_t error_code = XYZIMAGE_ERROR_OK;

	FILE* f = fopen("WHATEVER.xyz", "rb");

	XYZImage* img = xyzimage_fopen(f, &error_code);

	if (error_code != XYZIMAGE_ERROR_OK) {
		return 1;
	}

	fclose(f);

	f = fopen("/tmp/out.xyz", "wb");

	xyzimage_fwrite(img, f, &error_code);

	if (error_code != XYZIMAGE_ERROR_OK) {
		return 1;
	}

	xyzimage_free(img);

	return 0;
}