From: John Tsiombikas <nuclear@member.fsf.org>
Date: Fri, 4 Nov 2022 22:14:11 +0000 (+0200)
Subject: add missing tools/pngdump to the repo
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=commitdiff_plain;h=HEAD;p=gbajam22

add missing tools/pngdump to the repo
---

diff --git a/.gitignore b/.gitignore
index 1dd77b1..6dc338a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,7 @@ cfg.mk
 *.elf
 *.a
 pngdump
+meshdump
 mmutil
 lutgen
 vistab
diff --git a/tools/pngdump/Makefile b/tools/pngdump/Makefile
new file mode 100644
index 0000000..d9b2878
--- /dev/null
+++ b/tools/pngdump/Makefile
@@ -0,0 +1,10 @@
+CFLAGS = -pedantic -Wall -Wno-unused-function -g
+LDFLAGS = -lpng -lz -lm
+
+pngdump: main.o image.o quant.o
+	$(CC) -o $@ $^ $(LDFLAGS)
+
+clean:
+	$(RM) main.o
+	$(RM) image.o
+	$(RM) pngdump
diff --git a/tools/pngdump/image.c b/tools/pngdump/image.c
new file mode 100644
index 0000000..7094888
--- /dev/null
+++ b/tools/pngdump/image.c
@@ -0,0 +1,676 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <png.h>
+#include "image.h"
+
+int alloc_image(struct image *img, int x, int y, int bpp)
+{
+	memset(img, 0, sizeof *img);
+	img->width = x;
+	img->height = y;
+	img->bpp = bpp;
+	img->scansz = img->pitch = x * (bpp == 15 ? 16 : bpp) / 8;
+
+	if(!(img->pixels = malloc(y * img->scansz))) {
+		fprintf(stderr, "failed to allocate %dx%d (%dbpp) pixel buffer\n", x, y, bpp);
+		return -1;
+	}
+
+	/* just a guess, assume the user will fill the details, but set up reasonable
+	 * defaults just in case...
+	 */
+	if(bpp <= 8) {
+		img->nchan = 1;
+		img->cmap_ncolors = 1 << bpp;
+	} else if(bpp <= 24) {
+		img->nchan = 3;
+	} else {
+		img->nchan = 4;
+	}
+	return 0;
+}
+
+int load_image(struct image *img, const char *fname)
+{
+	int i;
+	FILE *fp;
+	png_struct *png;
+	png_info *info;
+	int chan_bits, color_type;
+	png_uint_32 xsz, ysz;
+	png_color *palette;
+	unsigned char **scanline;
+	unsigned char *dptr;
+
+	if(!(fp = fopen(fname, "rb"))) {
+		fprintf(stderr, "failed to open: %s: %s\n", fname, strerror(errno));
+		return -1;
+	}
+
+	if(!(png = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0))) {
+		fclose(fp);
+		return -1;
+	}
+	if(!(info = png_create_info_struct(png))) {
+		fclose(fp);
+		png_destroy_read_struct(&png, 0, 0);
+		return -1;
+	}
+	if(setjmp(png_jmpbuf(png))) {
+		fclose(fp);
+		png_destroy_read_struct(&png, &info, 0);
+		return -1;
+	}
+
+	png_init_io(png, fp);
+	png_read_png(png, info, 0, 0);
+
+	png_get_IHDR(png, info, &xsz, &ysz, &chan_bits, &color_type, 0, 0, 0);
+	img->width = xsz;
+	img->height = ysz;
+	img->nchan = png_get_channels(png, info);
+	img->bpp = img->nchan * chan_bits;
+	img->scansz = img->pitch = xsz * img->bpp / 8;
+	img->cmap_ncolors = 0;
+
+	if(color_type == PNG_COLOR_TYPE_PALETTE) {
+		png_get_PLTE(png, info, &palette, &img->cmap_ncolors);
+		memcpy(img->cmap, palette, img->cmap_ncolors * sizeof *img->cmap);
+	}
+
+	if(!(img->pixels = malloc(ysz * img->scansz))) {
+		perror("failed to allocate pixel buffer");
+		fclose(fp);
+		png_destroy_read_struct(&png, &info, 0);
+		return -1;
+	}
+	dptr = img->pixels;
+
+	scanline = (unsigned char**)png_get_rows(png, info);
+	for(i=0; i<ysz; i++) {
+		memcpy(dptr, scanline[i], img->scansz);
+		dptr += img->pitch;
+	}
+
+	fclose(fp);
+	png_destroy_read_struct(&png, &info, 0);
+	return 0;
+}
+
+int save_image(struct image *img, const char *fname)
+{
+	FILE *fp;
+	int res;
+
+	if(!(fp = fopen(fname, "wb"))) {
+		fprintf(stderr, "save_image: failed to open: %s: %s\n", fname, strerror(errno));
+		return -1;
+	}
+	res = save_image_file(img, fp);
+	fclose(fp);
+	return res;
+}
+
+int save_image_file(struct image *img, FILE *fp)
+{
+	int i, chan_bits, coltype;
+	png_struct *png;
+	png_info *info;
+	png_text txt;
+	unsigned char **scanline = 0;
+	unsigned char *pptr;
+
+	if(!(png = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0))) {
+		fclose(fp);
+		return -1;
+	}
+	if(!(info = png_create_info_struct(png))) {
+		png_destroy_write_struct(&png, 0);
+		fclose(fp);
+		return -1;
+	}
+
+	txt.compression = PNG_TEXT_COMPRESSION_NONE;
+	txt.key = "Software";
+	txt.text = "pngdump";
+	txt.text_length = 0;
+
+	if(setjmp(png_jmpbuf(png))) {
+		png_destroy_write_struct(&png, &info);
+		free(scanline);
+		fclose(fp);
+		return -1;
+	}
+
+	switch(img->nchan) {
+	case 1:
+		if(img->cmap_ncolors > 0) {
+			coltype = PNG_COLOR_TYPE_PALETTE;
+		} else {
+			coltype = PNG_COLOR_TYPE_GRAY;
+		}
+		break;
+	case 2:
+		coltype = PNG_COLOR_TYPE_GRAY_ALPHA;
+		break;
+	case 3:
+		coltype = PNG_COLOR_TYPE_RGB;
+		break;
+	case 4:
+		coltype = PNG_COLOR_TYPE_RGB_ALPHA;
+		break;
+	}
+
+	chan_bits = img->bpp / img->nchan;
+	png_set_IHDR(png, info, img->width, img->height, chan_bits, coltype, PNG_INTERLACE_NONE,
+			PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+	png_set_text(png, info, &txt, 1);
+
+	if(img->cmap_ncolors > 0) {
+		png_set_PLTE(png, info, (png_color*)img->cmap, img->cmap_ncolors);
+	}
+
+	if(!(scanline = malloc(img->height * sizeof *scanline))) {
+		png_destroy_write_struct(&png, &info);
+		fclose(fp);
+		return -1;
+	}
+
+	pptr = img->pixels;
+	for(i=0; i<img->height; i++) {
+		scanline[i] = pptr;
+		pptr += img->pitch;
+	}
+	png_set_rows(png, info, scanline);
+
+	png_init_io(png, fp);
+	png_write_png(png, info, 0, 0);
+	png_destroy_write_struct(&png, &info);
+	free(scanline);
+	return 0;
+}
+
+
+int cmp_image(struct image *a, struct image *b)
+{
+	int i;
+	unsigned char *aptr = a->pixels;
+	unsigned char *bptr = b->pixels;
+
+	if(a->width != b->width || a->height != b->height || a->bpp != b->bpp || a->nchan != b->nchan) {
+		return -1;
+	}
+
+	for(i=0; i<a->height; i++) {
+		if(memcmp(aptr, bptr, a->scansz) != 0) {
+			return -1;
+		}
+		aptr += a->pitch;
+		bptr += b->pitch;
+	}
+	return 0;
+}
+
+void blit(struct image *src, int sx, int sy, int w, int h, struct image *dst, int dx, int dy)
+{
+	int i;
+	unsigned char *sptr, *dptr;
+
+	assert(src->bpp == dst->bpp);
+	assert(src->nchan == dst->nchan);
+
+	if(sx < 0) { w += sx; sx = 0; }
+	if(sy < 0) { h += sy; sy = 0; }
+	if(dx < 0) { w += dx; sx -= dx; dx = 0; }
+	if(dy < 0) { h += dy; sy -= dy; dy = 0; }
+	if(sx + w >= src->width) w = src->width - sx;
+	if(sy + h >= src->height) h = src->height - sy;
+	if(dx + w >= dst->width) w = dst->width - dx;
+	if(dy + h >= dst->height) h = dst->height - dy;
+
+	if(w <= 0 || h <= 0) return;
+
+	sptr = src->pixels + sy * src->pitch + sx * src->bpp / 8;
+	dptr = dst->pixels + dy * dst->pitch + dx * dst->bpp / 8;
+
+	for(i=0; i<h; i++) {
+		memcpy(dptr, sptr, w * dst->bpp / 8);
+		dptr += dst->pitch;
+		sptr += src->pitch;
+	}
+}
+
+unsigned int get_pixel(struct image *img, int x, int y)
+{
+	unsigned int r, g, b;
+	unsigned char *pptr;
+	unsigned short *pptr16;
+	unsigned int *pptr32;
+
+	switch(img->bpp) {
+	case 4:
+		pptr = img->pixels + y * img->pitch + x / 2;
+		return x & 1 ? *pptr & 0xf : *pptr >> 4;
+	case 8:
+		pptr = img->pixels + y * img->pitch + x;
+		return *pptr;
+	case 15:
+	case 16:
+		pptr16 = (unsigned short*)(img->pixels + y * img->pitch + x * 2);
+		return *pptr16;
+	case 24:
+		pptr = img->pixels + y * img->pitch + x * 3;
+		r = pptr[0];
+		g = pptr[1];
+		b = pptr[2];
+		return r | (g << 8) | (b << 16);
+	case 32:
+		pptr32 = (unsigned int*)(img->pixels + y * img->pitch + x * 4);
+		return *pptr32;
+
+	default:
+		fprintf(stderr, "get_pixel not implemented for %d bpp\n", img->bpp);
+	}
+
+	return 0;
+}
+
+unsigned int get_pixel_rgb(struct image *img, int x, int y, unsigned int *rgb)
+{
+	unsigned int pix = get_pixel(img, x, y);
+
+	switch(img->bpp) {
+	case 15:
+		rgb[0] = (pix & 0x7c00) >> 7;
+		rgb[1] = (pix & 0x03e0) >> 2;
+		rgb[2] = (pix & 0x001f) << 3;
+		rgb[0] |= ((rgb[0] & 8) >> 1) | ((rgb[0] & 8) >> 2) | ((rgb[0] & 8) >> 3);
+		rgb[1] |= ((rgb[1] & 8) >> 1) | ((rgb[1] & 8) >> 2) | ((rgb[1] & 8) >> 3);
+		rgb[2] |= ((rgb[2] & 8) >> 1) | ((rgb[2] & 8) >> 2) | ((rgb[2] & 8) >> 3);
+		break;
+
+	case 16:
+		rgb[0] = (pix & 0xf800) >> 8;
+		rgb[1] = (pix & 0x07e0) >> 3;
+		rgb[2] = (pix & 0x001f) << 3;
+		rgb[0] |= ((rgb[0] & 8) >> 1) | ((rgb[0] & 8) >> 2) | ((rgb[0] & 8) >> 3);
+		rgb[1] |= ((rgb[1] & 4) >> 1) | ((rgb[1] & 4) >> 2);
+		rgb[2] |= ((rgb[2] & 8) >> 1) | ((rgb[2] & 8) >> 2) | ((rgb[2] & 8) >> 3);
+		break;
+
+	case 24:
+	case 32:
+		rgb[0] = pix & 0xff;
+		rgb[1] = (pix >> 8) & 0xff;
+		rgb[2] = (pix >> 16) & 0xff;
+		break;
+
+	default:
+		assert(pix >= 0 && pix < img->cmap_ncolors);
+		rgb[0] = img->cmap[pix].r;
+		rgb[1] = img->cmap[pix].g;
+		rgb[2] = img->cmap[pix].b;
+	}
+
+	return pix;
+}
+
+void put_pixel(struct image *img, int x, int y, unsigned int pix)
+{
+	unsigned char *pptr;
+	unsigned short *pptr16;
+
+	switch(img->bpp) {
+	case 4:
+		pptr = img->pixels + y * img->pitch + x / 2;
+		if(x & 1) {
+			*pptr = (*pptr & 0xf0) | pix;
+		} else {
+			*pptr = (*pptr & 0xf) | (pix << 4);
+		}
+		break;
+
+	case 8:
+		pptr = img->pixels + y * img->pitch + x;
+		*pptr = pix;
+		break;
+
+	case 15:
+	case 16:
+		pptr16 = (unsigned short*)(img->pixels + y * img->pitch + x * 2);
+		*pptr16 = pix;
+		break;
+
+	default:
+		fprintf(stderr, "put_pixel not implemented for %d bpp\n", img->bpp);
+	}
+}
+
+void overlay_key(struct image *src, unsigned int key, struct image *dst)
+{
+	int i, j;
+	unsigned int pix;
+
+	assert(src->bpp == dst->bpp);
+	assert(src->width == dst->width);
+	assert(src->height == dst->height);
+
+	for(i=0; i<dst->height; i++) {
+		for(j=0; j<dst->width; j++) {
+			pix = get_pixel(src, j, i);
+			if(pix != key) {
+				put_pixel(dst, j, i, pix);
+			}
+		}
+	}
+}
+
+#if 0
+/* ---- color quantization ---- */
+struct octnode;
+
+struct octree {
+	struct octnode *root;
+	struct octnode *levn[8];
+	int ncol, maxcol;
+};
+
+struct octnode {
+	struct octree *tree;
+	int r, g, b, nref;
+	int palidx;
+	int nsub;
+	struct octnode *sub[8];
+	struct octnode *next;
+};
+
+static void add_color(struct octree *ot, int r, int g, int b);
+static void reduce_colors(struct octree *ot);
+static int assign_colors(struct octnode *on, int next, struct cmapent *cmap);
+static int lookup_color(struct octree *ot, int r, int g, int b);
+static struct octnode *new_node(struct octree *ot, int lvl);
+static void del_node(struct octnode *on, int lvl);
+static void print_tree(struct octnode *n, int lvl);
+static int count_leaves(struct octnode *n);
+
+void quantize_image(struct image *img, int maxcol)
+{
+	int i, j, cidx;
+	unsigned int rgb[3];
+	struct octree ot = {0};
+	struct image newimg = *img;
+
+	if(img->bpp > 8) {
+		newimg.bpp = 8;
+		newimg.nchan = 1;
+		newimg.scansz = newimg.width;
+		newimg.pitch = 8 * img->pitch / img->bpp;
+	}
+
+	ot.root = new_node(&ot, 0);
+	ot.maxcol = maxcol;
+
+	for(i=0; i<img->height; i++) {
+		for(j=0; j<img->width; j++) {
+			get_pixel_rgb(img, j, i, rgb);
+			add_color(&ot, rgb[0], rgb[1], rgb[2]);
+
+			while(count_leaves(ot.root) > ot.maxcol) {
+			//while(ot.ncol > ot.maxcol) {
+				reduce_colors(&ot);
+			}
+		}
+	}
+
+	/* use created octree to generate the palette */
+	newimg.cmap_ncolors = assign_colors(ot.root, 0, newimg.cmap);
+
+	/* replace image pixels */
+	for(i=0; i<img->height; i++) {
+		for(j=0; j<img->width; j++) {
+			get_pixel_rgb(img, j, i, rgb);
+			cidx = lookup_color(&ot, rgb[0], rgb[1], rgb[2]);
+			assert(cidx >= 0 && cidx < maxcol);
+			put_pixel(&newimg, j, i, cidx);
+		}
+	}
+
+	*img = newimg;
+}
+
+static int subidx(int bit, int r, int g, int b)
+{
+	assert(bit >= 0 && bit < 8);
+	bit = 7 - bit;
+	return ((r >> bit) & 1) | ((g >> (bit - 1)) & 2) | ((b >> (bit - 2)) & 4);
+}
+
+static int tree_height(struct octnode *on)
+{
+	int i, subh, max = 0;
+
+	if(!on) return 0;
+
+	for(i=0; i<8; i++) {
+		subh = tree_height(on->sub[i]);
+		if(subh > max) max = subh;
+	}
+	return max + 1;
+}
+
+static void add_color(struct octree *ot, int r, int g, int b)
+{
+	int i, idx;
+	struct octnode *on;
+
+	on = ot->root;
+	for(i=0; i<8; i++) {
+		idx = subidx(i, r, g, b);
+
+		if(!on->sub[idx]) {
+			on->sub[idx] = new_node(ot, i + 1);
+			if(i == 7) {
+				/* this only adds a color if the parent node was previously not
+				 * a leaf. Otherwise the new one just takes the parent's place
+				 */
+				ot->ncol++;
+			}
+			on->nsub++;
+		}
+
+		on->r += r;
+		on->g += g;
+		on->b += b;
+		on->nref++;
+
+		on = on->sub[idx];
+	}
+
+	on->r += r;
+	on->g += g;
+	on->b += b;
+	on->nref++;
+}
+
+static int count_nodes(struct octnode *n)
+{
+	int count = 0;
+	while(n) {
+		count++;
+		n = n->next;
+	}
+	return count;
+}
+
+static int count_leaves(struct octnode *n)
+{
+	int i, cnt;
+
+	if(!n) return 0;
+	if(n->nsub <= 0) return 1;
+
+	cnt = 0;
+	for(i=0; i<8; i++) {
+		cnt += count_leaves(n->sub[i]);
+	}
+	return cnt;
+}
+
+static void reduce_colors(struct octree *ot)
+{
+	int i, lvl, best_nref;
+	struct octnode *n, *best;
+
+	lvl = 8;
+	while(--lvl >= 0) {
+		best_nref = INT_MAX;
+		best = 0;
+		n = ot->levn[lvl];
+
+		while(n) {
+			if(n->nref < best_nref && n->nsub) {
+				best = n;
+				best_nref = n->nref;
+			}
+			n = n->next;
+		}
+
+		if(best) {
+			for(i=0; i<8; i++) {
+				if(best->sub[i]) {
+					del_node(best->sub[i], lvl + 1);
+					best->sub[i] = 0;
+				}
+			}
+			if(best->nsub) {
+				/* this wasn't previously a leaf, but now it is */
+				ot->ncol++;
+				best->nsub = 0;
+			}
+			break;
+		}
+	}
+}
+
+static int assign_colors(struct octnode *on, int next, struct cmapent *cmap)
+{
+	int i;
+
+	if(!on) return next;
+
+	if(on->nsub <= 0) {
+		assert(next < on->tree->maxcol);
+		cmap[next].r = on->r / on->nref;
+		cmap[next].g = on->g / on->nref;
+		cmap[next].b = on->b / on->nref;
+		on->palidx = next++;
+	}
+
+	for(i=0; i<8; i++) {
+		next = assign_colors(on->sub[i], next, cmap);
+	}
+	return next;
+}
+
+static int lookup_color(struct octree *ot, int r, int g, int b)
+{
+	int i, idx;
+	struct octnode *on = ot->root;
+
+	for(i=0; i<8; i++) {
+		idx = subidx(i, r, g, b);
+		if(!on->sub[idx]) break;
+		on = on->sub[idx];
+	}
+
+	return on->palidx;
+}
+
+static int have_node(struct octnode *list, struct octnode *n)
+{
+	while(list) {
+		if(list == n) return 1;
+		list = list->next;
+	}
+	return 0;
+}
+
+static struct octnode *new_node(struct octree *ot, int lvl)
+{
+	struct octnode *on;
+
+	if(!(on = calloc(1, sizeof *on))) {
+		perror("failed to allocate octree node");
+		abort();
+	}
+
+	on->tree = ot;
+	on->palidx = -1;
+
+	if(lvl < 8) {
+		if(have_node(ot->levn[lvl], on)) {
+			fprintf(stderr, "double-insertion!\n");
+			abort();
+		}
+		on->next = ot->levn[lvl];
+		ot->levn[lvl] = on;
+	}
+	return on;
+}
+
+static void del_node(struct octnode *on, int lvl)
+{
+	int i;
+	struct octree *ot;
+	struct octnode dummy, *prev;
+
+	if(!on) return;
+	ot = on->tree;
+
+	if(!on->nsub) {
+		ot->ncol--;	/* removing a leaf removes a color */
+	}
+
+	for(i=0; i<8; i++) {
+		del_node(on->sub[i], lvl + 1);
+	}
+
+	if(lvl < 8) {
+		dummy.next = ot->levn[lvl];
+		prev = &dummy;
+
+		while(prev->next) {
+			if(prev->next == on) {
+				prev->next = on->next;
+				break;
+			}
+			prev = prev->next;
+		}
+		ot->levn[lvl] = dummy.next;
+	}
+
+	free(on);
+}
+
+static void print_tree(struct octnode *n, int lvl)
+{
+	int i;
+
+	if(!n) return;
+
+	for(i=0; i<lvl; i++) {
+		fputs("|  ", stdout);
+	}
+
+	printf("+-%p: <%d %d %d> #%d", (void*)n, n->r, n->g, n->b, n->nref);
+	if(n->palidx >= 0) printf(" [%d]\n", n->palidx);
+	putchar('\n');
+
+	for(i=0; i<8; i++) {
+		print_tree(n->sub[i], lvl + 1);
+	}
+}
+#endif
diff --git a/tools/pngdump/image.h b/tools/pngdump/image.h
new file mode 100644
index 0000000..f86de94
--- /dev/null
+++ b/tools/pngdump/image.h
@@ -0,0 +1,38 @@
+#ifndef IMAGE_H_
+#define IMAGE_H_
+
+#include <stdio.h>
+
+struct cmapent {
+	unsigned char r, g, b;
+};
+
+struct image {
+	int width, height;
+	int bpp;
+	int nchan;
+	int scansz;	/* scanline size in bytes */
+	int pitch;	/* bytes from one scanline to the next */
+	int cmap_ncolors;
+	struct cmapent cmap[256];
+	unsigned char *pixels;
+};
+
+int alloc_image(struct image *img, int x, int y, int bpp);
+int load_image(struct image *img, const char *fname);
+int save_image(struct image *img, const char *fname);
+int save_image_file(struct image *img, FILE *fp);
+
+int cmp_image(struct image *a, struct image *b);
+
+void blit(struct image *src, int sx, int sy, int w, int h, struct image *dst, int dx, int dy);
+void overlay_key(struct image *src, unsigned int key, struct image *dst);
+
+unsigned int get_pixel(struct image *img, int x, int y);
+unsigned int get_pixel_rgb(struct image *img, int x, int y, unsigned int *rgb);
+void put_pixel(struct image *img, int x, int y, unsigned int pix);
+
+int quantize_image(struct image *img, int maxcol);
+int gen_shades(struct image *img, int levels, int maxcol, int *shade_lut);
+
+#endif	/* IMAGE_H_ */
diff --git a/tools/pngdump/main.c b/tools/pngdump/main.c
new file mode 100644
index 0000000..f62621e
--- /dev/null
+++ b/tools/pngdump/main.c
@@ -0,0 +1,430 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <errno.h>
+#include <assert.h>
+#include "image.h"
+
+enum {
+	MODE_PIXELS,
+	MODE_CMAP,
+	MODE_PNG,
+	MODE_INFO
+};
+
+void conv_gba_image(struct image *img);
+void dump_colormap(struct image *img, int text, FILE *fp);
+void print_usage(const char *argv0);
+
+int main(int argc, char **argv)
+{
+	int i, j, mode = 0;
+	int text = 0;
+	int renibble = 0;
+	char *outfname = 0;
+	char *slut_fname = 0, *cmap_fname = 0;
+	char *infiles[256];
+	int num_infiles = 0;
+	struct image img, tmpimg;
+	FILE *out = stdout;
+	FILE *aux_out;
+	int *shade_lut = 0;
+	int *lutptr;
+	int shade_levels = 8;
+	int maxcol = 0;
+	int lvl;
+	int conv_555 = 0;
+	int gbacolors = 0;
+
+	for(i=1; i<argc; i++) {
+		if(argv[i][0] == '-') {
+			if(argv[i][2] == 0) {
+				switch(argv[i][1]) {
+				case 'P':
+					mode = MODE_PNG;
+					break;
+
+				case 'p':
+					mode = MODE_PIXELS;
+					break;
+
+				case 'c':
+					mode = MODE_CMAP;
+					break;
+
+				case 'i':
+					mode = MODE_INFO;
+					break;
+
+				case 'C':
+					if(!argv[++i] || (maxcol = atoi(argv[i])) < 2 || maxcol > 256) {
+						fprintf(stderr, "-C must be followed by the number of colors to reduce down to\n");
+						return 1;
+					}
+					break;
+
+				case 's':
+					if(!argv[++i] || (shade_levels = atoi(argv[i])) == 0) {
+						fprintf(stderr, "-s must be followed by the number of shade levels\n");
+						return 1;
+					}
+					break;
+
+				case 't':
+					text = 1;
+					break;
+
+				case 'n':
+					renibble = 1;
+					break;
+
+				case 'g':
+					gbacolors = 1;
+					break;
+
+				case 'o':
+					if(!argv[++i]) {
+						fprintf(stderr, "%s must be followed by a filename\n", argv[i - 1]);
+						return 1;
+					}
+					outfname = argv[i];
+					break;
+
+				case 'h':
+					print_usage(argv[0]);
+					return 0;
+
+				default:
+					fprintf(stderr, "invalid option: %s\n", argv[i]);
+					print_usage(argv[0]);
+					return 1;
+				}
+			} else {
+				if(strcmp(argv[i], "-oc") == 0) {
+					if(!argv[++i]) {
+						fprintf(stderr, "-oc must be followed by a filename\n");
+						return 1;
+					}
+					cmap_fname = argv[i];
+
+				} else if(strcmp(argv[i], "-os") == 0) {
+					if(!argv[++i]) {
+						fprintf(stderr, "-os must be followed by a filename\n");
+						return 1;
+					}
+					slut_fname = argv[i];
+
+				} else if(strcmp(argv[i], "-555") == 0) {
+					conv_555 = 1;
+
+				} else {
+					fprintf(stderr, "invalid option: %s\n", argv[i]);
+					print_usage(argv[0]);
+					return 1;
+				}
+			}
+		} else {
+			infiles[num_infiles++] = argv[i];
+		}
+	}
+
+	if(!num_infiles) {
+		fprintf(stderr, "pass the filename of a PNG file\n");
+		return 1;
+	}
+	if(load_image(&img, infiles[0]) == -1) {
+		fprintf(stderr, "failed to load PNG file: %s\n", infiles[0]);
+		return 1;
+	}
+
+	if(gbacolors) {
+		conv_gba_image(&img);
+	}
+
+	for(i=1; i<num_infiles; i++) {
+		if(load_image(&tmpimg, infiles[i]) == -1) {
+			fprintf(stderr, "failed to load PNG file: %s\n", infiles[i]);
+			return 1;
+		}
+		if(tmpimg.width != img.width || tmpimg.height != img.height) {
+			fprintf(stderr, "size mismatch: first image (%s) is %dx%d, %s is %dx%d\n",
+					infiles[0], img.width, img.height, infiles[i], tmpimg.width, tmpimg.height);
+			return 1;
+		}
+		if(tmpimg.bpp != img.bpp) {
+			fprintf(stderr, "bpp mismatch: first image (%s) is %d bpp, %s is %d bpp\n",
+					infiles[0], img.bpp, infiles[i], img.bpp);
+			return 1;
+		}
+
+		overlay_key(&tmpimg, 0, &img);
+	}
+
+	/* generate shading LUT and quantize image as necessary */
+	if(slut_fname) {
+		if(img.bpp > 8) {
+			fprintf(stderr, "shading LUT generation is only supported for indexed color images\n");
+			return 1;
+		}
+		if(!(aux_out = fopen(slut_fname, "wb"))) {
+			fprintf(stderr, "failed to open shading LUT output file: %s: %s\n", slut_fname, strerror(errno));
+			return 1;
+		}
+
+		if(!maxcol) maxcol = 256;
+
+		if(!(shade_lut = malloc(maxcol * shade_levels * sizeof *shade_lut))) {
+			fprintf(stderr, "failed to allocate shading look-up table\n");
+			return 1;
+		}
+
+		gen_shades(&img, shade_levels, maxcol, shade_lut);
+
+		lutptr = shade_lut;
+		for(i=0; i<maxcol; i++) {
+			for(j=0; j<shade_levels; j++) {
+				lvl = lutptr[shade_levels - j - 1];
+				if(text) {
+					fprintf(aux_out, "%d%c", lvl, j < shade_levels - 1 ? ' ' : '\n');
+				} else {
+					fputc(lvl, aux_out);
+				}
+			}
+			lutptr += shade_levels;
+		}
+		fclose(aux_out);
+
+	} else if(maxcol) {
+		/* perform any color reductions if requested */
+		if(img.bpp <= 8 && img.cmap_ncolors <= maxcol) {
+			fprintf(stderr, "requested reduction to %d colors, but image has %d colors\n", maxcol, img.cmap_ncolors);
+			return 1;
+		}
+		quantize_image(&img, maxcol);
+	}
+
+	if(cmap_fname) {
+		if(img.bpp > 8) {
+			fprintf(stderr, "colormap output works only for indexed color images\n");
+			return 1;
+		}
+		if(!(aux_out = fopen(cmap_fname, "wb"))) {
+			fprintf(stderr, "failed to open colormap output file: %s: %s\n", cmap_fname, strerror(errno));
+			return 1;
+		}
+		dump_colormap(&img, text, aux_out);
+		fclose(aux_out);
+	}
+
+	if(img.bpp == 4 && renibble) {
+		unsigned char *ptr = img.pixels;
+		for(i=0; i<img.width * img.height; i++) {
+			unsigned char p = *ptr;
+			*ptr++ = (p << 4) | (p >> 4);
+		}
+	}
+
+	if(conv_555) {
+		struct image img555;
+		unsigned int rgb24[3], rgb15;
+
+		if(alloc_image(&img555, img.width, img.height, 15) == -1) {
+			fprintf(stderr, "failed to allocate temporary %dx%d image for 555 conversion\n",
+					img.width, img.height);
+			return 1;
+		}
+
+		for(i=0; i<img.height; i++) {
+			for(j=0; j<img.width; j++) {
+				get_pixel_rgb(&img, j, i, rgb24);
+				rgb15 = ((rgb24[0] >> 3) & 0x1f) | ((rgb24[1] << 2) & 0x3e0) |
+					((rgb24[2] << 7) & 0x7c00);
+				put_pixel(&img555, j, i, rgb15);
+			}
+		}
+		free(img.pixels);
+		img = img555;
+	}
+
+	if(outfname) {
+		if(!(out = fopen(outfname, "wb"))) {
+			fprintf(stderr, "failed to open output file: %s: %s\n", outfname, strerror(errno));
+			return 1;
+		}
+	}
+
+	switch(mode) {
+	case MODE_PNG:
+		save_image_file(&img, out);
+		break;
+
+	case MODE_PIXELS:
+		fwrite(img.pixels, 1, img.scansz * img.height, out);
+		break;
+
+	case MODE_CMAP:
+		dump_colormap(&img, text, out);
+		break;
+
+	case MODE_INFO:
+		printf("size: %dx%d\n", img.width, img.height);
+		printf("bit depth: %d\n", img.bpp);
+		printf("scanline size: %d bytes\n", img.scansz);
+		if(img.cmap_ncolors > 0) {
+			printf("colormap entries: %d\n", img.cmap_ncolors);
+		} else {
+			printf("color channels: %d\n", img.nchan);
+		}
+		break;
+	}
+
+	fclose(out);
+	return 0;
+}
+
+#define MIN(a, b)			((a) < (b) ? (a) : (b))
+#define MIN3(a, b, c)		((a) < (b) ? MIN(a, c) : MIN(b, c))
+#define MAX(a, b)			((a) > (b) ? (a) : (b))
+#define MAX3(a, b, c)		((a) > (b) ? MAX(a, c) : MAX(b, c))
+
+void rgb_to_hsv(float *rgb, float *hsv)
+{
+	float min, max, delta;
+
+	min = MIN3(rgb[0], rgb[1], rgb[2]);
+	max = MAX3(rgb[0], rgb[1], rgb[2]);
+	delta = max - min;
+
+	if(max == 0) {
+		hsv[0] = hsv[1] = hsv[2] = 0;
+		return;
+	}
+
+	hsv[2] = max;			/* value */
+	hsv[1] = delta / max;	/* saturation */
+
+	if(delta == 0.0f) {
+		hsv[0] = 0.0f;
+	} else if(max == rgb[0]) {
+		hsv[0] = (rgb[1] - rgb[2]) / delta;
+	} else if(max == rgb[1]) {
+		hsv[0] = 2.0f + (rgb[2] - rgb[0]) / delta;
+	} else {
+		hsv[0] = 4.0f + (rgb[0] - rgb[1]) / delta;
+	}
+	/*
+	hsv[0] /= 6.0f;
+
+	if(hsv[0] < 0.0f) hsv[0] += 1.0f;
+	*/
+	hsv[0] *= 60.0f;
+	if(hsv[0] < 0) hsv[0] += 360;
+	hsv[0] /= 360.0f;
+}
+
+#define RETRGB(r, g, b) \
+	do { \
+		rgb[0] = r; \
+		rgb[1] = g; \
+		rgb[2] = b; \
+		return; \
+	} while(0)
+
+void hsv_to_rgb(float *hsv, float *rgb)
+{
+	float sec, frac, o, p, q;
+	int hidx;
+
+	if(hsv[1] == 0.0f) {
+		rgb[0] = rgb[1] = rgb[2] = hsv[2];	/* value */
+	}
+
+	sec = floor(hsv[0] * (360.0f / 60.0f));
+	frac = (hsv[0] * (360.0f / 60.0f)) - sec;
+
+	o = hsv[2] * (1.0f - hsv[1]);
+	p = hsv[2] * (1.0f - hsv[1] * frac);
+	q = hsv[2] * (1.0f - hsv[1] * (1.0f - frac));
+
+	hidx = (int)sec;
+	switch(hidx) {
+	default:
+	case 0: RETRGB(hsv[2], q, o);
+	case 1: RETRGB(p, hsv[2], o);
+	case 2: RETRGB(o, hsv[2], q);
+	case 3: RETRGB(o, p, hsv[2]);
+	case 4: RETRGB(q, o, hsv[2]);
+	case 5: RETRGB(hsv[2], o, p);
+	}
+}
+
+void gba_color(struct cmapent *color)
+{
+	float rgb[3], hsv[3];
+
+	rgb[0] = pow((float)color->r / 255.0f, 2.2);
+	rgb[1] = pow((float)color->g / 255.0f, 2.2);
+	rgb[2] = pow((float)color->b / 255.0f, 2.2);
+
+	/* saturate colors */
+	rgb_to_hsv(rgb, hsv);
+	hsv[1] *= 1.2f;
+	hsv[2] *= 2.0f;
+	if(hsv[1] > 1.0f) hsv[1] = 1.0f;
+	if(hsv[2] > 1.0f) hsv[2] = 1.0f;
+	hsv_to_rgb(hsv, rgb);
+
+	rgb[0] = pow(rgb[0], 1.0 / 2.6);
+	rgb[1] = pow(rgb[1], 1.0 / 2.6);
+	rgb[2] = pow(rgb[2], 1.0 / 2.6);
+
+	color->r = (int)(rgb[0] * 255.0f);
+	color->g = (int)(rgb[1] * 255.0f);
+	color->b = (int)(rgb[2] * 255.0f);
+}
+
+void conv_gba_image(struct image *img)
+{
+	int i;
+
+	if(img->cmap_ncolors) {
+		for(i=0; i<img->cmap_ncolors; i++) {
+			gba_color(img->cmap + i);
+		}
+	} else {
+		/* TODO */
+	}
+}
+
+void dump_colormap(struct image *img, int text, FILE *fp)
+{
+	int i;
+
+	if(text) {
+		for(i=0; i<img->cmap_ncolors; i++) {
+			fprintf(fp, "%d %d %d\n", img->cmap[i].r, img->cmap[i].g, img->cmap[i].b);
+		}
+	} else {
+		fwrite(img->cmap, sizeof img->cmap[0], 1 << img->bpp, fp);
+	}
+}
+
+void print_usage(const char *argv0)
+{
+	printf("Usage: %s [options] <input file>\n", argv0);
+	printf("Options:\n");
+	printf(" -o <output file>: specify output file (default: stdout)\n");
+	printf(" -oc <cmap file>: output colormap to separate file\n");
+	printf(" -os <lut file>: generate and output shading LUT\n");
+	printf(" -p: dump pixels (default)\n");
+	printf(" -P: output in PNG format\n");
+	printf(" -c: dump colormap (palette) entries\n");
+	printf(" -C <colors>: reduce image down to specified number of colors\n");
+	printf(" -s <shade levels>: used in conjunction with -os (default: 8)\n");
+	printf(" -i: print image information\n");
+	printf(" -t: output as text when possible\n");
+	printf(" -n: swap the order of nibbles (for 4bpp)\n");
+	printf(" -555: convert to BGR555\n");
+	printf(" -h: print usage and exit\n");
+}
diff --git a/tools/pngdump/quant.c b/tools/pngdump/quant.c
new file mode 100644
index 0000000..4dc2fee
--- /dev/null
+++ b/tools/pngdump/quant.c
@@ -0,0 +1,396 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <errno.h>
+#include <assert.h>
+#include "image.h"
+
+#define NUM_LEVELS	8
+
+struct octnode;
+
+struct octree {
+	struct octnode *root;
+	struct octnode *redlist[NUM_LEVELS];
+	int redlev;
+	int nleaves, maxcol;
+};
+
+struct octnode {
+	int lvl;
+	struct octree *tree;
+	int r, g, b, nref;
+	int palidx;
+	int nsub, leaf;
+	struct octnode *sub[8];
+	struct octnode *next;
+};
+
+
+static void init_octree(struct octree *tree, int maxcol);
+static void destroy_octree(struct octree *tree);
+
+static struct octnode *alloc_node(struct octree *tree, int lvl);
+static void free_node(struct octnode *n);
+static void free_tree(struct octnode *n);
+
+static void add_color(struct octree *tree, int r, int g, int b, int nref);
+static void reduce_colors(struct octree *tree);
+static int assign_colors(struct octnode *n, int next, struct cmapent *cmap);
+static int lookup_color(struct octree *tree, int r, int g, int b);
+static int subidx(int bit, int r, int g, int b);
+static void print_tree(struct octnode *n, int lvl);
+
+int quantize_image(struct image *img, int maxcol)
+{
+	int i, j, cidx;
+	unsigned int rgb[3];
+	struct octree tree;
+	struct image newimg = *img;
+
+	if(maxcol < 2 || maxcol > 256) {
+		return -1;
+	}
+
+	if(img->bpp > 8) {
+		newimg.bpp = maxcol > 16 ? 8 : 4;
+		newimg.nchan = 1;
+		newimg.scansz = newimg.width * newimg.bpp / 8;
+		newimg.pitch = newimg.scansz;
+	}
+
+	init_octree(&tree, maxcol);
+
+	for(i=0; i<img->height; i++) {
+		for(j=0; j<img->width; j++) {
+			get_pixel_rgb(img, j, i, rgb);
+			add_color(&tree, rgb[0], rgb[1], rgb[2], 1);
+
+			while(tree.nleaves > maxcol) {
+				reduce_colors(&tree);
+			}
+		}
+	}
+
+	/* use created octree to generate the palette */
+	newimg.cmap_ncolors = assign_colors(tree.root, 0, newimg.cmap);
+
+	/* replace image pixels */
+	for(i=0; i<img->height; i++) {
+		for(j=0; j<img->width; j++) {
+			get_pixel_rgb(img, j, i, rgb);
+			cidx = lookup_color(&tree, rgb[0], rgb[1], rgb[2]);
+			assert(cidx >= 0 && cidx < maxcol);
+			put_pixel(&newimg, j, i, cidx);
+		}
+	}
+
+	*img = newimg;
+
+	destroy_octree(&tree);
+	return 0;
+}
+
+int gen_shades(struct image *img, int levels, int maxcol, int *shade_lut)
+{
+	int i, j, cidx, r, g, b;
+	unsigned int color[3];
+	struct octree tree;
+	struct image newimg = *img;
+
+	if(maxcol < 2 || maxcol > 256) {
+		return -1;
+	}
+
+	init_octree(&tree, maxcol);
+
+	for(i=0; i<img->cmap_ncolors; i++) {
+		add_color(&tree, img->cmap[i].r, img->cmap[i].g, img->cmap[i].b, 1024);
+	}
+
+	for(i=0; i<img->cmap_ncolors; i++) {
+		for(j=0; j<levels - 1; j++) {
+			r = img->cmap[i].r * j / (levels - 1);
+			g = img->cmap[i].g * j / (levels - 1);
+			b = img->cmap[i].b * j / (levels - 1);
+			add_color(&tree, r, g, b, 1);
+
+			while(tree.nleaves > maxcol) {
+				reduce_colors(&tree);
+			}
+		}
+	}
+
+	newimg.cmap_ncolors = assign_colors(tree.root, 0, newimg.cmap);
+
+	/* replace image pixels */
+	for(i=0; i<img->height; i++) {
+		for(j=0; j<img->width; j++) {
+			get_pixel_rgb(img, j, i, color);
+			cidx = lookup_color(&tree, color[0], color[1], color[2]);
+			put_pixel(&newimg, j, i, cidx);
+		}
+	}
+
+	/* populate shade_lut based on the new palette, can't generate levels only
+	 * for the original colors, because the palette entries will have changed
+	 * and moved around.
+	 */
+	for(i=0; i<newimg.cmap_ncolors; i++) {
+		for(j=0; j<levels; j++) {
+			r = newimg.cmap[i].r * j / (levels - 1);
+			g = newimg.cmap[i].g * j / (levels - 1);
+			b = newimg.cmap[i].b * j / (levels - 1);
+			*shade_lut++ = lookup_color(&tree, r, g, b);
+		}
+	}
+	for(i=0; i<(maxcol - newimg.cmap_ncolors) * levels; i++) {
+		*shade_lut++ = maxcol - 1;
+	}
+
+	*img = newimg;
+
+	destroy_octree(&tree);
+	return 0;
+}
+
+static void init_octree(struct octree *tree, int maxcol)
+{
+	memset(tree, 0, sizeof *tree);
+
+	tree->redlev = NUM_LEVELS - 1;
+	tree->maxcol = maxcol;
+
+	tree->root = alloc_node(tree, 0);
+}
+
+static void destroy_octree(struct octree *tree)
+{
+	free_tree(tree->root);
+}
+
+static struct octnode *alloc_node(struct octree *tree, int lvl)
+{
+	struct octnode *n;
+
+	if(!(n = calloc(1, sizeof *n))) {
+		perror("failed to allocate octree node");
+		abort();
+	}
+
+	n->lvl = lvl;
+	n->tree = tree;
+	n->palidx = -1;
+
+	if(lvl < tree->redlev) {
+		n->next = tree->redlist[lvl];
+		tree->redlist[lvl] = n;
+	} else {
+		n->leaf = 1;
+		tree->nleaves++;
+	}
+	return n;
+}
+
+static void free_node(struct octnode *n)
+{
+	struct octnode *prev, dummy;
+
+	dummy.next = n->tree->redlist[n->lvl];
+	prev = &dummy;
+	while(prev->next) {
+		if(prev->next == n) {
+			prev->next = n->next;
+			break;
+		}
+		prev = prev->next;
+	}
+	n->tree->redlist[n->lvl] = dummy.next;
+
+	if(n->leaf) {
+		n->tree->nleaves--;
+		assert(n->tree->nleaves >= 0);
+	}
+	free(n);
+}
+
+static void free_tree(struct octnode *n)
+{
+	int i;
+
+	if(!n) return;
+
+	for(i=0; i<8; i++) {
+		free_tree(n->sub[i]);
+	}
+	free_node(n);
+}
+
+static void add_color(struct octree *tree, int r, int g, int b, int nref)
+{
+	int i, idx, rr, gg, bb;
+	struct octnode *n;
+
+	rr = r * nref;
+	gg = g * nref;
+	bb = b * nref;
+
+	n = tree->root;
+	n->r += rr;
+	n->g += gg;
+	n->b += bb;
+	n->nref += nref;
+
+	for(i=0; i<NUM_LEVELS; i++) {
+		if(n->leaf) break;
+
+		idx = subidx(i, r, g, b);
+
+		if(!n->sub[idx]) {
+			n->sub[idx] = alloc_node(tree, i + 1);
+		}
+		n->nsub++;
+		n = n->sub[idx];
+
+		n->r += rr;
+		n->g += gg;
+		n->b += bb;
+		n->nref += nref;
+	}
+}
+
+static struct octnode *get_reducible(struct octree *tree)
+{
+	int best_nref;
+	struct octnode dummy, *n, *prev, *best_prev, *best = 0;
+
+	while(tree->redlev >= 0) {
+		best_nref = INT_MAX;
+		best = 0;
+		dummy.next = tree->redlist[tree->redlev];
+		prev = &dummy;
+		while(prev->next) {
+			n = prev->next;
+			if(n->nref < best_nref) {
+				best = n;
+				best_nref = n->nref;
+				best_prev = prev;
+			}
+			prev = prev->next;
+		}
+		if(best) {
+			best_prev->next = best->next;
+			tree->redlist[tree->redlev] = dummy.next;
+			break;
+		}
+		tree->redlev--;
+	}
+
+	return best;
+}
+
+static void reduce_colors(struct octree *tree)
+{
+	int i;
+	struct octnode *n;
+
+	if(!(n = get_reducible(tree))) {
+		fprintf(stderr, "warning: no reducible nodes!\n");
+		return;
+	}
+	for(i=0; i<8; i++) {
+		if(n->sub[i]) {
+			free_node(n->sub[i]);
+			n->sub[i] = 0;
+		}
+	}
+	n->leaf = 1;
+	tree->nleaves++;
+}
+
+static int assign_colors(struct octnode *n, int next, struct cmapent *cmap)
+{
+	int i;
+
+	if(!n) return next;
+
+	if(n->leaf) {
+		assert(next < n->tree->maxcol);
+		assert(n->nref);
+		cmap[next].r = n->r / n->nref;
+		cmap[next].g = n->g / n->nref;
+		cmap[next].b = n->b / n->nref;
+		n->palidx = next;
+		return next + 1;
+	}
+
+	for(i=0; i<8; i++) {
+		next = assign_colors(n->sub[i], next, cmap);
+	}
+	return next;
+}
+
+static int lookup_color(struct octree *tree, int r, int g, int b)
+{
+	int i, j, idx;
+	struct octnode *n;
+
+	n = tree->root;
+	for(i=0; i<NUM_LEVELS; i++) {
+		if(n->leaf) {
+			assert(n->palidx >= 0);
+			return n->palidx;
+		}
+
+		idx = subidx(i, r, g, b);
+		for(j=0; j<8; j++) {
+			if(n->sub[idx]) break;
+			idx = (idx + 1) & 7;
+		}
+
+		assert(n->sub[idx]);
+		n = n->sub[idx];
+	}
+
+	fprintf(stderr, "lookup_color(%d, %d, %d) failed!\n", r, g, b);
+	abort();
+	return -1;
+}
+
+static int subidx(int bit, int r, int g, int b)
+{
+	assert(bit >= 0 && bit < NUM_LEVELS);
+	bit = NUM_LEVELS - 1 - bit;
+	return ((r >> bit) & 1) | ((g >> (bit - 1)) & 2) | ((b >> (bit - 2)) & 4);
+}
+
+static void print_tree(struct octnode *n, int lvl)
+{
+	int i;
+	char ptrbuf[32], *p;
+
+	if(!n) return;
+
+	for(i=0; i<lvl; i++) {
+		fputs("|  ", stdout);
+	}
+
+	sprintf(ptrbuf, "%p", (void*)n);
+	p = ptrbuf + strlen(ptrbuf) - 4;
+
+	if(n->nref) {
+		printf("+-(%d) %s: <%d %d %d> #%d", n->lvl, p, n->r / n->nref, n->g / n->nref,
+				n->b / n->nref, n->nref);
+	} else {
+		printf("+-(%d) %s: <- - -> #0", n->lvl, p);
+	}
+	if(n->palidx >= 0) printf(" [%d]", n->palidx);
+	if(n->leaf) printf(" LEAF");
+	putchar('\n');
+
+	for(i=0; i<8; i++) {
+		print_tree(n->sub[i], lvl + 1);
+	}
+}
+