split format work into seperate functions. Only JPEG works for now

3 files changed, 122 insertions, 72 deletions

diff --git a/src/jpeg.c b/src/jpeg.c
index 749d448..68efa39 100644
--- a/src/jpeg.c
+++ b/src/jpeg.c
@@ -15,67 +15,92 @@ struct error_mgr{
 };
 
 static void error_exit(j_common_ptr cinfo){
+	(void) cinfo;
 	printf("\nerror!\n");
 	exit(1);
 }
 
-unsigned char *loadjpeg(FILE *infile, int *width, int *height){
+struct jpeg_t{
+	struct image img;
+	FILE *f;
 	struct jpeg_decompress_struct cinfo;
 	struct error_mgr jerr;
+};
+
+static struct image *jpeg_open(FILE *f){
+	struct jpeg_t *j;
+
+	rewind(f);
+	if(getc(f) != 0xff || getc(f) != 0xd8)
+		return NULL;
+
+	j = malloc(sizeof(struct jpeg_t));
+	j->f = f;
+	rewind(f);
+
+	j->cinfo.err = jpeg_std_error(&j->jerr.pub);
+	j->jerr.pub.error_exit = error_exit;
+
+	jpeg_create_decompress(&j->cinfo);
+	jpeg_stdio_src(&j->cinfo, f);
+	jpeg_read_header(&j->cinfo, TRUE);
+
+	/* parameters */
+	j->cinfo.do_fancy_upsampling = 0;
+	j->cinfo.do_block_smoothing = 0;
+	j->cinfo.quantize_colors = 0;
+	j->cinfo.dct_method = JDCT_IFAST;
 
+	jpeg_calc_output_dimensions(&j->cinfo);
+
+	j->img.width = j->cinfo.output_width;
+	j->img.height = j->cinfo.output_height;
+
+	return (struct image *)j;
+}
+
+static int jpeg_read(struct image *img){
+	struct jpeg_t *j = (struct jpeg_t *)img;
 	JSAMPARRAY buffer;
 	int row_stride;
-	int i = 0;
-	int j, y, x;
-	unsigned char *retbuf;
+	int a = 0, b;
+	unsigned int x, y;
 
-	cinfo.err = jpeg_std_error(&jerr.pub);
-	jerr.pub.error_exit = error_exit;
+	row_stride = j->cinfo.output_width * j->cinfo.output_components;
+	buffer = (*j->cinfo.mem->alloc_sarray)((j_common_ptr)&j->cinfo, JPOOL_IMAGE, row_stride, 4);
 
-	jpeg_create_decompress(&cinfo);
-	jpeg_stdio_src(&cinfo, infile);
-	jpeg_read_header(&cinfo, TRUE);
+	jpeg_start_decompress(&j->cinfo);
 
-	/* parameters */
-	cinfo.do_fancy_upsampling = 0;
-	cinfo.do_block_smoothing = 0;
-	cinfo.quantize_colors = 0;
-	cinfo.dct_method = JDCT_IFAST;
-	
-	jpeg_calc_output_dimensions(&cinfo);
-	row_stride = cinfo.output_width * cinfo.output_components;
-	buffer = (*cinfo.mem->alloc_sarray)((j_common_ptr)&cinfo, JPOOL_IMAGE, row_stride, 4);
-	
-	jpeg_start_decompress(&cinfo);
-	*width = cinfo.output_width;
-	*height = cinfo.output_height;
-	retbuf = malloc(3 * (cinfo.output_width * cinfo.output_height));
-
-	if(cinfo.output_components == 3){
-		for(y = 0; y < cinfo.output_height; ){
-			int n = jpeg_read_scanlines(&cinfo, buffer, 4);
-			for(j = 0; j < n; j++){
-				memcpy(&retbuf[i], buffer[j], row_stride);
-				i += row_stride;
+	if(j->cinfo.output_components == 3){
+		for(y = 0; y < j->cinfo.output_height; ){
+			int n = jpeg_read_scanlines(&j->cinfo, buffer, 4);
+			for(b = 0; b < n; b++){
+				memcpy(&img->buf[a], buffer[b], row_stride);
+				a += row_stride;
 			}
 			y += n;
 		}
-	}else if(cinfo.output_components == 1){
-		for(y = 0; y < cinfo.output_height; ){
-			int n = jpeg_read_scanlines(&cinfo, buffer, 4);
-			for(j = 0; j < n; j++){
-				for(x = 0; x < cinfo.output_width; x++){
-					retbuf[i++] = buffer[j][x];
-					retbuf[i++] = buffer[j][x];
-					retbuf[i++] = buffer[j][x];
+	}else if(j->cinfo.output_components == 1){
+		for(y = 0; y < j->cinfo.output_height; ){
+			int n = jpeg_read_scanlines(&j->cinfo, buffer, 4);
+			for(b = 0; b < n; b++){
+				for(x = 0; x < j->cinfo.output_width; x++){
+					img->buf[a++] = buffer[b][x];
+					img->buf[a++] = buffer[b][x];
+					img->buf[a++] = buffer[b][x];
 				}
 			}
 			y += n;
 		}
 	}
-	jpeg_finish_decompress(&cinfo);
-	jpeg_destroy_decompress(&cinfo);
-	return retbuf;
+	jpeg_finish_decompress(&j->cinfo);
+	jpeg_destroy_decompress(&j->cinfo);
+
+	return 0;
 }
 
+struct imageformat jpeg = {
+	jpeg_open,
+	jpeg_read
+};
 
diff --git a/src/main.c b/src/main.c
index cbb0fdc..74cb4ca 100644
--- a/src/main.c
+++ b/src/main.c
@@ -12,6 +12,14 @@
 
 #include "meh.h"
 
+/* Supported Formats */
+extern struct imageformat jpeg;
+struct imageformat *formats[] = {
+	&jpeg,
+	NULL
+};
+
+/* Globals */
 Display *display;
 int screen;
 Window window;
@@ -120,30 +128,32 @@ XImage *create_image_from_buffer(unsigned char *buf, int width, int height, int
 	return img;
 }
 
-unsigned char *loadbuf(const char *filename, int *bufwidth, int *bufheight){
+struct image *imgopen(const char *filename){
+	struct image *img = NULL;
+	struct imageformat **fmt = formats;
 	FILE *f;
-	unsigned char head[4];
-	unsigned char *buf;
-
 	if((f = fopen(filename, "rb")) == NULL){
 		fprintf(stderr, "Cannot open '%s'\n", filename);
 		return NULL;
 	}
-	memset(head, 0, 4);
-	fread(head, 1, 4, f);
-	rewind(f);
-	if(head[0] == 0xff && head[1] == 0xd8){
-		buf = loadjpeg(f, bufwidth, bufheight);
-	}else if(!memcmp("\x89PNG", head, 4)){
-		buf = loadpng(f, bufwidth, bufheight);
-	}else if(!memcmp("GIF", head, 3)){
-		buf = loadgif(f, bufwidth, bufheight);
-	}else{
-		fprintf(stderr, "Unknown file type: '%s'\n", filename);
-		buf = NULL;
+	for(fmt = formats; *fmt; fmt++){
+		if((img = (*fmt)->open(f))){
+			img->fmt = *fmt;
+			return img;
+		}
 	}
-	fclose(f);
-	return buf;
+	fprintf(stderr, "Unknown file type: '%s'\n", filename);
+	return NULL;
+}
+
+unsigned char *loadbuf(const char *filename, int *bufwidth, int *bufheight){
+	struct image *img;
+	img = imgopen(filename);
+	img->buf = malloc(3 * img->width * img->height);
+	*bufwidth = img->width;
+	*bufheight = img->height;
+	img->fmt->read(img);
+	return img->buf;
 }
 
 struct imagenode{
@@ -194,7 +204,8 @@ void run(struct imagenode *image){
 	int imagewidth = 0, imageheight = 0;
 	int width = 0, height = 0;
 	int fillw = 0, fillh = 0;
-	XImage *img = NULL;
+	XImage *ximg = NULL;
+	struct image *img = NULL;
 	unsigned char *buf = NULL;
 	int redraw = 0;
 
@@ -210,11 +221,11 @@ void run(struct imagenode *image){
 					break;
 				case ConfigureNotify:
 					if(width != event.xconfigure.width || height != event.xconfigure.height){
-						if(img){
-							free(img->data);
-							XFree(img);
+						if(ximg){
+							free(ximg->data);
+							XFree(ximg);
 						}
-						img = NULL;
+						ximg = NULL;
 						width = event.xconfigure.width;
 						height = event.xconfigure.height;
 						redraw = 1;
@@ -240,13 +251,13 @@ void run(struct imagenode *image){
 								image = image->prev;
 								direction = -1;
 							}
-							if(img){
-								free(img->data);
-								XFree(img);
+							if(ximg){
+								free(ximg->data);
+								XFree(ximg);
 							}
 							if(buf)
 								free(buf);
-							img = NULL;
+							ximg = NULL;
 							buf = NULL;
 							redraw = 1;
 							break;
@@ -278,7 +289,7 @@ void run(struct imagenode *image){
 				setaspect(bufwidth, bufheight);
 				continue;
 			}
-			if(!img){
+			if(!ximg){
 				if(width * bufheight > height * bufwidth){
 					imagewidth = bufwidth * height / bufheight;
 					imageheight = height;
@@ -301,11 +312,11 @@ void run(struct imagenode *image){
 					imagewidth = width;
 					imageheight = height;
 				}
-				img = create_image_from_buffer(buf, imagewidth, imageheight, bufwidth, bufheight);
-				assert(img);
+				ximg = create_image_from_buffer(buf, imagewidth, imageheight, bufwidth, bufheight);
+				assert(ximg);
 			}
 			XFillRectangle(display, window, gc, 0, 0, fillw, fillh);
-			XPutImage(display, window, gc, img, 0, 0, xoffset, yoffset, width, height);
+			XPutImage(display, window, gc, ximg, 0, 0, xoffset, yoffset, width, height);
 			XFillRectangle(display, window, gc, width - fillw, height - fillh, fillw, fillh);
 			XFlush(display);
 			redraw = 0;
diff --git a/src/meh.h b/src/meh.h
index 719b717..0e1a410 100644
--- a/src/meh.h
+++ b/src/meh.h
@@ -1,6 +1,20 @@
 
 #include <stdio.h>
 
+struct image;
+
+struct imageformat{
+	struct image *(*open)(FILE *);
+	int (*read)(struct image *);
+};
+
+struct image{
+	unsigned char *buf;
+	int width, height;
+	FILE *f;
+	struct imageformat *fmt;
+};
+
 unsigned char *loadgif(FILE *, int *, int *);
 unsigned char *loadjpeg(FILE *, int *, int *);
 unsigned char *loadpng(FILE *, int *, int *);