initial

5 files changed, 271 insertions, 0 deletions

diff --git a/src/jpeg.c b/src/jpeg.c
new file mode 100644
index 0000000..6d3b40c
--- /dev/null
+++ b/src/jpeg.c
@@ -0,0 +1,54 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "jpeglib.h"
+
+#include "jpeg.h"
+
+unsigned char *loadjpeg(char *filename, int *width, int *height){
+	struct jpeg_decompress_struct cinfo;
+	struct jpeg_error_mgr jerr;
+
+	FILE *infile;
+	JSAMPARRAY buffer;
+	int row_stride;
+	int i = 0;
+	int x, y;
+	unsigned char *retbuf;
+
+	if((infile = fopen(filename, "rb")) == NULL){
+		fprintf(stderr, "can't open %s\n", filename);
+		exit(1);
+	}
+
+	cinfo.err = jpeg_std_error(&jerr);
+	jpeg_create_decompress(&cinfo);
+	jpeg_stdio_src(&cinfo, infile);
+	jpeg_read_header(&cinfo, TRUE);
+	jpeg_start_decompress(&cinfo);
+	*width = cinfo.output_width;
+	*height = cinfo.output_height;
+	retbuf = malloc(cinfo.output_components * (cinfo.output_width * cinfo.output_height));
+
+	if(cinfo.output_components != 3){
+		fprintf(stderr, "TODO: greyscale images are not supported\n");
+		exit(1);
+	}
+	row_stride = cinfo.output_width * cinfo.output_components;
+	buffer = (*cinfo.mem->alloc_sarray)((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
+	for(y = 0; y < cinfo.output_height; y++){
+		jpeg_read_scanlines(&cinfo, buffer, 1);
+		for(x = 0; x < row_stride; x++){
+			retbuf[i++] = buffer[0][x];
+		}
+		assert(i % *width == 0);
+	}
+	jpeg_finish_decompress(&cinfo);
+	jpeg_destroy_decompress(&cinfo);
+	fclose(infile);
+	return retbuf;
+}
+
+
diff --git a/src/jpeg.h b/src/jpeg.h
new file mode 100644
index 0000000..c834f76
--- /dev/null
+++ b/src/jpeg.h
@@ -0,0 +1,3 @@
+
+unsigned char *loadjpeg(char *filename, int *width, int *height);
+
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..b4ce5ce
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,210 @@
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <X11/Xlib.h>
+#include <X11/keysym.h>
+
+#include "jpeg.h"
+#include "util.h"
+
+Display *display;
+int screen;
+Window window;
+GC gc;
+
+void usage(){
+	printf("USAGE: meh [FILE1 [FILE2 [...]]]");
+	exit(1);
+}
+
+static int popcount(unsigned long mask){
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+    return __builtin_popcount(mask);
+#else
+    int y;
+
+    y = (mask >> 1) &033333333333;
+    y = mask - y - ((y >>1) & 033333333333);
+    return (((y + (y >> 3)) & 030707070707) % 077);
+#endif
+}
+
+
+unsigned int getshift(unsigned int mask){
+	return popcount((mask - 1) & ~mask) & 31;
+}
+
+XImage *create_image_from_buffer(unsigned char *buf, int width, int height, int bufwidth, int bufheight) {
+	int depth;
+	XImage *img = NULL;
+	Visual *vis;
+	unsigned int rshift, gshift, bshift;
+	int outIndex = 0;	
+	int i;
+	int x,y;
+	int numBufBytes = (3 * bufwidth * bufheight);
+	
+	depth = DefaultDepth(display, screen);
+	vis = DefaultVisual(display, screen);
+
+	rshift = getshift(vis->red_mask);
+	gshift = getshift(vis->green_mask);
+	bshift = getshift(vis->blue_mask);
+
+	if (depth >= 24) {
+		size_t numNewBufBytes = (4 * (width * height));
+		u_int32_t *newBuf = malloc(numNewBufBytes);
+	
+		//for(outIndex = 0; outIndex < width * height; outIndex++){
+		for(y = 0; y < height; y++){
+			for(x = 0; x < width; x++){
+				unsigned int r, g, b;
+				i = (y * bufheight / height * bufwidth + x * bufwidth / width) * 3;
+				assert(i < numBufBytes);
+				r = (buf[i++] << rshift) & vis->red_mask;
+				g = (buf[i++] << gshift) & vis->green_mask;
+				b = (buf[i++] << bshift) & vis->blue_mask;
+				
+				newBuf[y * width + x] = r | g | b;
+			}
+		}		
+		
+		img = XCreateImage (display, 
+			CopyFromParent, depth, 
+			ZPixmap, 0, 
+			(char *) newBuf,
+			width, height,
+			32, 0
+		);
+		
+	} else if (depth >= 15) {
+		exit(1);
+		size_t numNewBufBytes = (2 * (width * height));
+		u_int16_t *newBuf = malloc (numNewBufBytes);
+		
+		for (i = 0; i < numBufBytes;) {
+			unsigned int r, g, b;
+			r = (buf[i++] << rshift) & vis->red_mask;
+			g = (buf[i++] << gshift) & vis->green_mask;
+			b = (buf[i++] << bshift) & vis->blue_mask;
+			
+			newBuf[outIndex++] = r | g | b;
+		}		
+		
+		img = XCreateImage (display,
+			CopyFromParent, depth,
+			ZPixmap, 0,
+			(char *) newBuf,
+			width, height,
+			16, 0
+		);
+	} else {
+		fprintf (stderr, "This program does not support displays with a depth less than 15.");
+		exit(1);
+		return NULL;				
+	}
+
+	XInitImage (img);
+
+	return img;
+}		
+
+
+void init(){
+	display = XOpenDisplay (NULL);
+	assert(display);
+	screen = DefaultScreen(display);
+
+	window = XCreateWindow(display, DefaultRootWindow(display), 0, 0, 640, 480, 0, DefaultDepth(display, screen), InputOutput, CopyFromParent, 0, NULL);
+	gc = XCreateGC(display, window, 0, NULL);
+
+	XMapRaised(display, window);
+	XSelectInput(display, window, StructureNotifyMask | ExposureMask | KeyPressMask);
+	XFlush(display);
+}
+
+void run(char *images[], int length){
+	int i = 0;
+	int bufwidth, bufheight;
+	int width = 0, height = 0;
+	XImage *img = NULL;
+	unsigned char *buf = NULL;
+	int redraw = 0;
+
+	for(;;){
+		XEvent event;
+		XNextEvent(display, &event);
+		switch(event.type){
+			case MapNotify:
+				printf("MapNotify\n");
+				break;
+			case ConfigureNotify:
+				printf("ConfigureNotify(%i, %i, %i, %i)\n", event.xconfigure.x, event.xconfigure.y, event.xconfigure.width, event.xconfigure.height);
+				if(width != event.xconfigure.width || height != event.xconfigure.height){
+					if(img)
+						free(img);
+					img = NULL;
+					width = event.xconfigure.width;
+					height = event.xconfigure.height;
+				}
+				break;
+			case Expose:
+				redraw = 1;
+				break;
+			case KeyPress:
+				switch(XLookupKeysym(&event.xkey, 0)){
+					case XK_Escape:
+						exit(0);
+						break;
+					case XK_q:
+						exit(0);
+						break;
+					case XK_t:
+						i = (i + 1) % length;
+						if(img)
+							free(img);
+						if(buf)
+							free(buf);
+						img = NULL;
+						buf = NULL;
+						redraw = 1;
+						break;
+					case XK_n:
+						i = i ? i - 1 : length - 1;
+						if(img)
+							free(img);
+						if(buf)
+							free(buf);
+						img = NULL;
+						buf = NULL;
+						redraw = 1;
+						break;
+				}
+				break;
+		}
+		if(redraw){
+			if(!buf)
+				buf = loadjpeg(images[i], &bufwidth, &bufheight);
+			assert(buf);
+			if(!img)
+				img = create_image_from_buffer(buf, width, height, bufwidth, bufheight);
+			assert(img);
+			XPutImage(display, window, gc, img, 0, 0, 0, 0, width, height);
+			XFlush(display);
+			redraw = 0;
+		}
+	}
+}
+
+int main(int argc, char *argv[]){
+	if(argc < 2)
+		usage();
+	init();
+
+	run(&argv[1], argc - 1);
+
+	return 0;
+}
+
diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..55538e7
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,3 @@
+
+#include "util.h"
+
diff --git a/src/util.h b/src/util.h
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/src/util.h
@@ -0,0 +1 @@
+