nuclear@4: #include <stdio.h>
nuclear@4: #include <stdlib.h>
nuclear@4: #include <string.h>
nuclear@4: #include <ctype.h>
nuclear@4: 
nuclear@5: #define RODATA_STR	"__attribute__((section(\".rodata\")))"
nuclear@5: 
nuclear@4: unsigned char *read_image(int *xsz, int *ysz, int *maxval);
nuclear@4: 
nuclear@5: int main(int argc, char **argv)
nuclear@4: {
nuclear@5: 	int i, j, width, height, xtiles, ytiles, maxval;
nuclear@5: 	unsigned char *pixels, *tiles, *src, *dest;
nuclear@5: 	const char *prefix = "img_";
nuclear@5: 
nuclear@5: 	if(argv[1]) {
nuclear@5: 		prefix = argv[1];
nuclear@5: 	}
nuclear@4: 
nuclear@4: 	if(!(pixels = read_image(&width, &height, &maxval))) {
nuclear@4: 		return 1;
nuclear@4: 	}
nuclear@4: 	fprintf(stderr, "read image %dx%d (maxval: %d)\n", width, height, maxval);
nuclear@4: 
nuclear@5: 	xtiles = width / 8;
nuclear@5: 	ytiles = height / 8;
nuclear@5: 	/* each tile is 32 bytes, 8 rows of 4 bytes each */
nuclear@5: 	if(!(tiles = malloc(xtiles * ytiles * 32))) {
nuclear@5: 		free(pixels);
nuclear@5: 		return 1;
nuclear@5: 	}
nuclear@4: 
nuclear@5: 	/* if we have 15 as max val, we'll assume they are straight palette indices
nuclear@5: 	 * otherwise, do color quantization and palette allocation
nuclear@5: 	 */
nuclear@5: 	if(maxval == 15) {
nuclear@5: 		/* just drop green/blue components in-place, keep red as index */
nuclear@5: 		dest = src = pixels;
nuclear@5: 		for(i=0; i<width * height; i++) {
nuclear@5: 			*dest++ = *src;
nuclear@5: 			src += 3;
nuclear@5: 		}
nuclear@5: 	} else {
nuclear@5: 		/* TODO */
nuclear@5: 	}
nuclear@5: 
nuclear@5: 	/* after processing, we have 1 color index per byte */
nuclear@5: 
nuclear@5: 	/* slice tiles and pack indices as nibbles */
nuclear@5: 	dest = tiles;
nuclear@5: 	for(i=0; i<ytiles; i++) {
nuclear@5: 		for(j=0; j<xtiles; j++) {
nuclear@5: 			int x, y;
nuclear@5: 			int tilestart = (i * xtiles * 8 + j) * 8;
nuclear@5: 
nuclear@5: 			for(y=0; y<8; y++) {
nuclear@5: 				for(x=0; x<4; x++) {
nuclear@5: 					src = pixels + tilestart + y * width + x * 2;
nuclear@5: 					*dest++ = (src[0] << 4) | (src[1] & 0xf);
nuclear@5: 				}
nuclear@5: 			}
nuclear@5: 
nuclear@4: 		}
nuclear@4: 	}
nuclear@4: 
nuclear@5: 	/* output as C array */
nuclear@5: 	printf("/* generated by ppm2md */\n");
nuclear@5: 	printf("int %sxtiles " RODATA_STR " = %d;\n", prefix, xtiles);
nuclear@5: 	printf("int %sytiles " RODATA_STR " = %d;\n", prefix, ytiles);
nuclear@5: 	printf("unsigned char %stiles[][32] " RODATA_STR " = {", prefix);
nuclear@5: 
nuclear@5: 	src = tiles;
nuclear@5: 	for(i=0; i<xtiles * ytiles; i++) {
nuclear@5: 		if(i > 0) {
nuclear@5: 			printf(",\n");
nuclear@5: 		} else {
nuclear@5: 			putchar('\n');
nuclear@5: 		}
nuclear@5: 		printf("\t{");
nuclear@5: 		for(j=0; j<32; j++) {
nuclear@5: 			if(j == 0) {
nuclear@5: 				printf("%u", (unsigned int)*src++);
nuclear@5: 			} else {
nuclear@5: 				printf(", %u", (unsigned int)*src++);
nuclear@5: 			}
nuclear@5: 		}
nuclear@5: 		printf(" }");
nuclear@5: 	}
nuclear@5: 	printf("\n};\n");
nuclear@5: 
nuclear@5: 
nuclear@4: 	return 0;
nuclear@4: }
nuclear@4: 
nuclear@4: char *clean_line(char *s)
nuclear@4: {
nuclear@4: 	char *tmp;
nuclear@4: 
nuclear@4: 	while(*s && isspace(*s)) {
nuclear@4: 		++s;
nuclear@4: 	}
nuclear@4: 
nuclear@4: 	tmp = strchr(s, '#');
nuclear@4: 	if(tmp) *tmp = 0;
nuclear@4: 	tmp = strchr(s, '\n');
nuclear@4: 	if(tmp) *tmp = 0;
nuclear@4: 	tmp = strchr(s, '\r');
nuclear@4: 	if(tmp) *tmp = 0;
nuclear@4: 
nuclear@4: 	return s;
nuclear@4: }
nuclear@4: 
nuclear@4: unsigned char *read_image(int *width, int *height, int *maxval)
nuclear@4: {
nuclear@4: 	char buf[256];
nuclear@4: 	int i, xsz, ysz, hdrline = 0;
nuclear@4: 	unsigned char *pixels;
nuclear@4: 
nuclear@4: 	while(hdrline < 3 && fgets(buf, sizeof buf, stdin)) {
nuclear@4: 		char *line = clean_line(buf);
nuclear@4: 		if(!*line) continue;
nuclear@4: 
nuclear@4: 		switch(hdrline) {
nuclear@4: 		case 0:
nuclear@4: 			if(strcmp(line, "P6") != 0) {
nuclear@4: 				goto inval;
nuclear@4: 			}
nuclear@4: 			break;
nuclear@4: 
nuclear@4: 		case 1:
nuclear@4: 			if(sscanf(line, "%d %d", &xsz, &ysz) != 2) {
nuclear@4: 				goto inval;
nuclear@4: 			}
nuclear@4: 			break;
nuclear@4: 
nuclear@4: 		case 2:
nuclear@4: 			if(sscanf(line, "%d", maxval) != 1) {
nuclear@4: 				goto inval;
nuclear@4: 			}
nuclear@4: 			break;
nuclear@4: 		}
nuclear@4: 		++hdrline;
nuclear@4: 	}
nuclear@4: 
nuclear@4: 	if(!(pixels = malloc(xsz * ysz * 3))) {
nuclear@4: 		fprintf(stderr, "failed to allocate image: %dx%d\n", xsz, ysz);
nuclear@4: 		return 0;
nuclear@4: 	}
nuclear@4: 
nuclear@4: 	for(i=0; i<xsz * ysz * 3; i++) {
nuclear@4: 		int c = getchar();
nuclear@4: 		if(c == -1) goto inval;
nuclear@4: 		pixels[i] = c;
nuclear@4: 	}
nuclear@4: 
nuclear@4: 	*width = xsz;
nuclear@4: 	*height = ysz;
nuclear@4: 	return pixels;
nuclear@4: 
nuclear@4: inval:
nuclear@4: 	fprintf(stderr, "invalid input\n");
nuclear@4: 	return 0;
nuclear@4: }