Add gfx tool for graphics postprocessing

tools/common.h

@@ -0,0 +1,37 @@
+#ifndef GUARD_COMMON_H
+#define GUARD_COMMON_H
+
+int __getopt_long_i__;
+#define getopt_long(c, v, s, l) getopt_long(c, v, s, l, &__getopt_long_i__)
+
+FILE *fopen_verbose(char *filename, char *mode) {
+	FILE *f = fopen(filename, mode);
+	if (!f) {
+		fprintf(stderr, "Could not open file: \"%s\"\n", filename);
+	}
+	return f;
+}
+
+uint8_t *read_u8(char *filename, int *size) {
+	FILE *f = fopen_verbose(filename, "rb");
+	if (!f) {
+		exit(1);
+	}
+	fseek(f, 0, SEEK_END);
+	*size = ftell(f);
+	rewind(f);
+	uint8_t *data = malloc(*size);
+	fread(data, 1, *size, f);
+	fclose(f);
+	return data;
+}
+
+void write_u8(char *filename, uint8_t *data, int size) {
+	FILE *f = fopen_verbose(filename, "wb");
+	if (f) {
+		fwrite(data, 1, size, f);
+		fclose(f);
+	}
+}
+
+#endif // GUARD_COMMON_H