Various improvements

.gitattributes

@@ -0,0 +1 @@
+*.dds -text

.gitignore

@@ -0,0 +1,6 @@
+*.o
+*~
+*.trace
+ddsinfo
+glddstest
+afl-mojodds

Makefile

@@ -0,0 +1,34 @@
+
+CC?=gcc
+CFLAGS?=-Wall -g -O -std=c99
+LDFLAGS?=-g
+
+CFLAGS+=$(shell sdl2-config --cflags)
+CFLAGS+=$(shell pkg-config glew --cflags)
+
+LDLIBS+=$(shell sdl2-config --libs)
+LDLIBS+=$(shell pkg-config glew --libs)
+
+
+.SUFFIXES: .o
+
+PROGRAMS:=ddsinfo glddstest afl-mojodds
+
+.PHONY: all clean
+
+all: $(PROGRAMS)
+
+clean:
+	-rm $(PROGRAMS) *.o
+
+
+ddsinfo: ddsinfo.o mojodds.o
+	$(CC) $(LDFLAGS) -o $@ $^
+
+
+glddstest: glddstest.o mojodds.o
+	$(CC) $(LDFLAGS) -o $@ $^ $(LDLIBS)
+
+
+afl-mojodds: afl-mojodds.o mojodds.o
+	$(CC) $(LDFLAGS) -o $@ $^

afl-mojodds.c

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+#include <assert.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "mojodds.h"
+
+
+// helper for fuzzing with AFL
+// if you don't know what this is you don't need it
+
+
+void __afl_manual_init(void);
+
+
+int main(int argc, char *argv[]) {
+	if (argc != 2) {
+		return 0;
+	}
+
+#ifdef __AFL_HAVE_MANUAL_INIT
+	__afl_manual_init();
+#endif  // __AFL_HAVE_MANUAL_INIT
+
+	const char *filename = argv[1];
+
+	FILE *f = fopen(filename, "rb");
+	if (!f) {
+		return 1;
+	}
+
+	fseek(f, 0, SEEK_END);
+	long size = ftell(f);
+	fseek(f, 0, SEEK_SET);
+
+	char *contents = malloc(size);
+	size_t readbytes = fread(contents, 1, size, f);
+	if (readbytes != size) {
+		free(contents);
+		fclose(f);
+		return 2;
+	}
+
+	fclose(f);
+
+	int isDDS = MOJODDS_isDDS(contents, size);
+	if (!isDDS) {
+		return 3;
+	}
+
+	const void *tex = NULL;
+	unsigned long texlen = 0;
+	unsigned int glfmt = 0, w = 0, h = 0, miplevels = 0;
+	unsigned int cubemapfacelen = 0;
+	MOJODDS_textureType textureType = 0;
+	int retval = MOJODDS_getTexture(contents, size, &tex, &texlen, &glfmt, &w, &h, &miplevels, &cubemapfacelen, &textureType);
+	if (!retval) {
+		free(contents);
+		return 4;
+	}
+
+	uint32_t hash = 0x12345678;
+	switch (textureType) {
+	case MOJODDS_TEXTURE_2D:
+	for (unsigned int miplevel = 0; miplevel < miplevels; miplevel++) {
+		const void *miptex = NULL;
+		unsigned long miptexlen = 0;
+		unsigned int mipW = 0, mipH = 0;
+		retval = MOJODDS_getMipMapTexture(miplevel, glfmt, tex, w, h, &miptex, &miptexlen, &mipW, &mipH);
+		if (!retval) {
+			continue;
+		}
+
+		// read every byte to make sure any buffer overflows actually overflow
+		const char *miptex_ = (const char *) miptex;
+		for (unsigned int i = 0; i < miptexlen; i++) {
+			hash = (hash * 65537) ^ miptex_[i];
+		}
+	}
+	break;
+
+	case MOJODDS_TEXTURE_CUBE:
+		for (MOJODDS_cubeFace cubeFace = MOJODDS_CUBEFACE_POSITIVE_X; cubeFace <= MOJODDS_CUBEFACE_NEGATIVE_Z; cubeFace++) {
+			for (unsigned int miplevel = 0; miplevel < miplevels; miplevel++) {
+				const void *miptex = NULL;
+				unsigned long miptexlen = 0;
+				unsigned int mipW = 0, mipH = 0;
+				retval = MOJODDS_getCubeFace(cubeFace, miplevel, glfmt, tex, cubemapfacelen, w, h, &miptex, &miptexlen, &mipW, &mipH);
+				if (!retval) {
+					continue;
+				}
+
+				// read every byte to make sure any buffer overflows actually overflow
+				const char *miptex_ = (const char *) miptex;
+				for (unsigned int i = 0; i < miptexlen; i++) {
+					hash = (hash * 65537) ^ miptex_[i];
+				}
+			}
+		}
+		break;
+
+	case MOJODDS_TEXTURE_VOLUME:
+		// TODO: do something with the data
+		break;
+
+	}
+	// do something the optimizer is not allowed to remove
+	printf("0x%08x\n", hash);
+
+	free(contents);
+
+	return 0;
+}

ddsinfo.c

@@ -0,0 +1,133 @@
+#include <errno.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "mojodds.h"
+
+
+// from http://graphics.stanford.edu/~seander/bithacks.html
+static bool isPow2(unsigned int v) {
+	return v && !(v & (v - 1));
+}
+
+
+static int ddsinfo(const char *filename) {
+    printf("%s\n", filename);
+
+	FILE *f = fopen(filename, "rb");
+	if (!f) {
+		printf("Error opening %s: %s (%d)\n", filename, strerror(errno), errno);
+		return 1;
+	}
+
+	fseek(f, 0, SEEK_END);
+	long size = ftell(f);
+	fseek(f, 0, SEEK_SET);
+
+	char *contents = malloc(size);
+	size_t readbytes = fread(contents, 1, size, f);
+	if (readbytes != size) {
+		printf("Only got %u of %ld bytes: %s\n", (unsigned int) readbytes, size, strerror(errno));
+		free(contents);
+		fclose(f);
+		return 2;
+	}
+
+	fclose(f);
+
+	int isDDS = MOJODDS_isDDS(contents, size);
+	printf("isDDS: %d\n", isDDS);
+	if (isDDS) {
+		const void *tex = NULL;
+		unsigned long texlen = 0;
+		unsigned int glfmt = 0, w = 0, h = 0, miplevels = 0;
+		unsigned int cubemapfacelen = 0;
+		MOJODDS_textureType textureType = 0;
+		int retval = MOJODDS_getTexture(contents, size, &tex, &texlen, &glfmt, &w, &h, &miplevels, &cubemapfacelen, &textureType);
+		if (!retval) {
+			printf("MOJODDS_getTexture failed\n");
+			free(contents);
+			return 3;
+		}
+
+		uintptr_t texoffset = ((const char *)(tex)) - contents;
+		printf("texoffset: %u\n", (unsigned int)(texoffset));
+		printf("texlen: %lu\n", texlen);
+		printf("glfmt: 0x%x\n", glfmt);
+		printf("width x height: %u x %u\n", w, h);
+		printf("miplevels: %u\n", miplevels);
+		printf("textureType: ");
+		switch (textureType) {
+		case MOJODDS_TEXTURE_2D:
+			printf("2D\n");
+		printf("\n");
+
+		for (unsigned int miplevel = 0; miplevel < miplevels; miplevel++) {
+			const void *miptex = NULL;
+			unsigned long miptexlen = 0;
+			unsigned int mipW = 0, mipH = 0;
+			retval = MOJODDS_getMipMapTexture(miplevel, glfmt, tex, w, h, &miptex, &miptexlen, &mipW, &mipH);
+			if (!retval) {
+				printf("MOJODDS_getMipMapTexture(%u) error: %d\n", miplevel, retval);
+				continue;
+			}
+
+			uintptr_t miptexoffset = ((const char *)(miptex)) - ((const char *)(tex));
+			bool npot = !(isPow2(mipW) || isPow2(mipH));
+			printf("%4u x %4u  %s", mipW, mipH, npot ? "NPOT  " : "      ");
+			printf("miptexoffset: %8u  ", (unsigned int)(miptexoffset));
+			printf("miptexlen: %8lu\n", miptexlen);
+		}
+			break;
+
+		case MOJODDS_TEXTURE_CUBE:
+			printf("cube\n");
+			printf("cubemapfacelen: %u\n", cubemapfacelen);
+			printf("\n");
+
+			for (unsigned int miplevel = 0; miplevel < miplevels; miplevel++) {
+				const void *miptex = NULL;
+				unsigned long miptexlen = 0;
+				unsigned int mipW = 0, mipH = 0;
+				retval = MOJODDS_getCubeFace(MOJODDS_CUBEFACE_POSITIVE_X, miplevel, glfmt, tex, cubemapfacelen, w, h, &miptex, &miptexlen, &mipW, &mipH);
+				if (!retval) {
+					printf("MOJODDS_getMipMapTexture(%u) error: %d\n", miplevel, retval);
+					continue;
+				}
+
+				uintptr_t miptexoffset = ((const char *)(miptex)) - ((const char *)(tex));
+				bool npot = !(isPow2(mipW) || isPow2(mipH));
+				printf("%4u x %4u  %s", mipW, mipH, npot ? "NPOT  " : "      ");
+				printf("miptexoffset: %8u  ", (unsigned int)(miptexoffset));
+				printf("miptexlen: %8lu\n", miptexlen);
+			}
+			break;
+
+		case MOJODDS_TEXTURE_VOLUME:
+			printf("volume\n");
+			break;
+
+		}
+	}
+
+	free(contents);
+
+	return 0;
+}
+
+
+int main(int argc, char *argv[]) {
+	if (argc < 2) {
+		printf("Usage: %s DDS-file ...\n", argv[0]);
+		return 0;
+	}
+
+	for (int i = 1; i < argc; i++) {
+		ddsinfo(argv[i]);
+	}
+
+	return 0;
+}