#define PROGNAME "rpng-x"
#define LONGNAME "Simple PNG Viewer for X"
#define VERSION "2.01 of 16 March 2008"
#define RESNAME "rpng"
#define RESCLASS "Rpng"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xos.h>
#include <X11/keysym.h>
#include "readpng.h"
#define alpha_composite(composite, fg, alpha, bg) { \
ush temp = ((ush)(fg)*(ush)(alpha) + \
(ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128); \
(composite) = (uch)((temp + (temp >> 8)) >> 8); \
}
static int rpng_x_create_window(void);
static int rpng_x_display_image(void);
static void rpng_x_cleanup(void);
static int rpng_x_msb(ulg u32val);
static char titlebar[1024], *window_name = titlebar;
static char *appname = LONGNAME;
static char *icon_name = PROGNAME;
static char *res_name = RESNAME;
static char *res_class = RESCLASS;
static char *filename;
static FILE *infile;
static char *bgstr;
static uch bg_red=0, bg_green=0, bg_blue=0;
static double display_exponent;
static ulg image_width, image_height, image_rowbytes;
static int image_channels;
static uch *image_data;
static char *displayname;
static XImage *ximage;
static Display *display;
static int depth;
static Visual *visual;
static XVisualInfo *visual_list;
static int RShift, GShift, BShift;
static ulg RMask, GMask, BMask;
static Window window;
static GC gc;
static Colormap colormap;
static int have_nondefault_visual = FALSE;
static int have_colormap = FALSE;
static int have_window = FALSE;
static int have_gc = FALSE;
int main(int argc, char **argv)
{
#ifdef sgi
char tmpline[80];
#endif
char *p;
int rc, alen, flen;
int error = 0;
int have_bg = FALSE;
double LUT_exponent;
double CRT_exponent = 2.2;
double default_display_exponent;
XEvent e;
KeySym k;
displayname = (char *)NULL;
filename = (char *)NULL;
#if defined(NeXT)
LUT_exponent = 1.0 / 2.2;
#elif defined(sgi)
LUT_exponent = 1.0 / 1.7;
infile = fopen("/etc/config/system.glGammaVal", "r");
if (infile) {
double sgi_gamma;
fgets(tmpline, 80, infile);
fclose(infile);
sgi_gamma = atof(tmpline);
if (sgi_gamma > 0.0)
LUT_exponent = 1.0 / sgi_gamma;
}
#elif defined(Macintosh)
LUT_exponent = 1.8 / 2.61;
#else
LUT_exponent = 1.0;
#endif
default_display_exponent = LUT_exponent * CRT_exponent;
if ((p = getenv("SCREEN_GAMMA")) != NULL)
display_exponent = atof(p);
else
display_exponent = default_display_exponent;
while (*++argv && !error) {
if (!strncmp(*argv, "-display", 2)) {
if (!*++argv)
++error;
else
displayname = *argv;
} else if (!strncmp(*argv, "-gamma", 2)) {
if (!*++argv)
++error;
else {
display_exponent = atof(*argv);
if (display_exponent <= 0.0)
++error;
}
} else if (!strncmp(*argv, "-bgcolor", 2)) {
if (!*++argv)
++error;
else {
bgstr = *argv;
if (strlen(bgstr) != 7 || bgstr[0] != '#')
++error;
else
have_bg = TRUE;
}
} else {
if (**argv != '-') {
filename = *argv;
if (argv[1])
++error;
} else
++error;
}
}
if (!filename)
++error;
if (error) {
fprintf(stderr, "\n%s %s: %s\n", PROGNAME, VERSION, appname);
readpng_version_info();
fprintf(stderr, "\n"
"Usage: %s [-display xdpy] [-gamma exp] [-bgcolor bg] file.png\n"
" xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
" exp \ttransfer-function exponent (``gamma'') of the display\n"
"\t\t system in floating-point format (e.g., ``%.1f''); equal\n"
"\t\t to the product of the lookup-table exponent (varies)\n"
"\t\t and the CRT exponent (usually 2.2); must be positive\n"
" bg \tdesired background color in 7-character hex RGB format\n"
"\t\t (e.g., ``#ff7700'' for orange: same as HTML colors);\n"
"\t\t used with transparent images\n"
"\nPress Q, Esc or mouse button 1 (within image window, after image\n"
"is displayed) to quit.\n"
"\n", PROGNAME, default_display_exponent);
exit(1);
}
if (!(infile = fopen(filename, "rb"))) {
fprintf(stderr, PROGNAME ": can't open PNG file [%s]\n", filename);
++error;
} else {
if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
switch (rc) {
case 1:
fprintf(stderr, PROGNAME
": [%s] is not a PNG file: incorrect signature\n",
filename);
break;
case 2:
fprintf(stderr, PROGNAME
": [%s] has bad IHDR (libpng longjmp)\n", filename);
break;
case 4:
fprintf(stderr, PROGNAME ": insufficient memory\n");
break;
default:
fprintf(stderr, PROGNAME
": unknown readpng_init() error\n");
break;
}
++error;
} else {
display = XOpenDisplay(displayname);
if (!display) {
readpng_cleanup(TRUE);
fprintf(stderr, PROGNAME ": can't open X display [%s]\n",
displayname? displayname : "default");
++error;
}
}
if (error)
fclose(infile);
}
if (error) {
fprintf(stderr, PROGNAME ": aborting.\n");
exit(2);
}
alen = strlen(appname);
flen = strlen(filename);
if (alen + flen + 3 > 1023)
sprintf(titlebar, "%s: ...%s", appname, filename+(alen+flen+6-1023));
else
sprintf(titlebar, "%s: %s", appname, filename);
if (have_bg) {
unsigned r, g, b;
sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
bg_red = (uch)r;
bg_green = (uch)g;
bg_blue = (uch)b;
} else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
readpng_cleanup(TRUE);
fprintf(stderr, PROGNAME
": libpng error while checking for background color\n");
exit(2);
}
if (rpng_x_create_window())
exit(2);
Trace((stderr, "calling readpng_get_image()\n"))
image_data = readpng_get_image(display_exponent, &image_channels,
&image_rowbytes);
Trace((stderr, "done with readpng_get_image()\n"))
readpng_cleanup(FALSE);
fclose(infile);
if (!image_data) {
fprintf(stderr, PROGNAME ": unable to decode PNG image\n");
exit(3);
}
Trace((stderr, "calling rpng_x_display_image()\n"))
if (rpng_x_display_image()) {
free(image_data);
exit(4);
}
Trace((stderr, "done with rpng_x_display_image()\n"))
printf(
"Done. Press Q, Esc or mouse button 1 (within image window) to quit.\n");
fflush(stdout);
do
XNextEvent(display, &e);
while (!(e.type == ButtonPress && e.xbutton.button == Button1) &&
!(e.type == KeyPress &&
((k = XLookupKeysym(&e.xkey, 0)) == XK_q || k == XK_Escape) ));
rpng_x_cleanup();
return 0;
}
static int rpng_x_create_window(void)
{
uch *xdata;
int need_colormap = FALSE;
int screen, pad;
ulg bg_pixel = 0L;
ulg attrmask;
Window root;
XEvent e;
XGCValues gcvalues;
XSetWindowAttributes attr;
XTextProperty windowName, *pWindowName = &windowName;
XTextProperty iconName, *pIconName = &iconName;
XVisualInfo visual_info;
XSizeHints *size_hints;
XWMHints *wm_hints;
XClassHint *class_hints;
screen = DefaultScreen(display);
depth = DisplayPlanes(display, screen);
root = RootWindow(display, screen);
#ifdef DEBUG
XSynchronize(display, True);
#endif
#if 0
if ( depth != 16 && depth != 24 && depth != 32) {
fprintf(stderr,
"screen depth %d not supported (only 16-, 24- or 32-bit TrueColor)\n",
depth);
return 2;
}
XMatchVisualInfo(display, screen, depth,
(depth == 8)? PseudoColor : TrueColor, &visual_info);
visual = visual_info.visual;
#else
if (depth != 16 && depth != 24 && depth != 32) {
int visuals_matched = 0;
Trace((stderr, "default depth is %d: checking other visuals\n",
depth))
visual_info.screen = screen;
visual_info.depth = 24;
visual_list = XGetVisualInfo(display,
VisualScreenMask | VisualDepthMask, &visual_info, &visuals_matched);
if (visuals_matched == 0) {
fprintf(stderr, "default screen depth %d not supported, and no"
" 24-bit visuals found\n", depth);
return 2;
}
Trace((stderr, "XGetVisualInfo() returned %d 24-bit visuals\n",
visuals_matched))
visual = visual_list[0].visual;
depth = visual_list[0].depth;
have_nondefault_visual = TRUE;
need_colormap = TRUE;
} else {
XMatchVisualInfo(display, screen, depth, TrueColor, &visual_info);
visual = visual_info.visual;
}
#endif
RMask = visual->red_mask;
GMask = visual->green_mask;
BMask = visual->blue_mask;
if (depth == 8 || need_colormap) {
colormap = XCreateColormap(display, root, visual, AllocNone);
if (!colormap) {
fprintf(stderr, "XCreateColormap() failed\n");
return 2;
}
have_colormap = TRUE;
}
if (depth == 15 || depth == 16) {
RShift = 15 - rpng_x_msb(RMask);
GShift = 15 - rpng_x_msb(GMask);
BShift = 15 - rpng_x_msb(BMask);
} else if (depth > 16) {
#define NO_24BIT_MASKS
#ifdef NO_24BIT_MASKS
RShift = rpng_x_msb(RMask) - 7;
GShift = rpng_x_msb(GMask) - 7;
BShift = rpng_x_msb(BMask) - 7;
#else
RShift = 7 - rpng_x_msb(RMask);
GShift = 7 - rpng_x_msb(GMask);
BShift = 7 - rpng_x_msb(BMask);
#endif
}
if (depth >= 15 && (RShift < 0 || GShift < 0 || BShift < 0)) {
fprintf(stderr, "rpng internal logic error: negative X shift(s)!\n");
return 2;
}
attr.backing_store = Always;
attr.event_mask = ExposureMask | KeyPressMask | ButtonPressMask;
attrmask = CWBackingStore | CWEventMask;
if (have_nondefault_visual) {
attr.colormap = colormap;
attr.background_pixel = 0;
attr.border_pixel = 1;
attrmask |= CWColormap | CWBackPixel | CWBorderPixel;
}
window = XCreateWindow(display, root, 0, 0, image_width, image_height, 0,
depth, InputOutput, visual, attrmask, &attr);
if (window == None) {
fprintf(stderr, "XCreateWindow() failed\n");
return 2;
} else
have_window = TRUE;
if (depth == 8)
XSetWindowColormap(display, window, colormap);
if (!XStringListToTextProperty(&window_name, 1, pWindowName))
pWindowName = NULL;
if (!XStringListToTextProperty(&icon_name, 1, pIconName))
pIconName = NULL;
if ((size_hints = XAllocSizeHints()) != NULL) {
size_hints->flags = PMinSize | PMaxSize;
size_hints->min_width = size_hints->max_width = (int)image_width;
size_hints->min_height = size_hints->max_height = (int)image_height;
}
if ((wm_hints = XAllocWMHints()) != NULL) {
wm_hints->initial_state = NormalState;
wm_hints->input = True;
wm_hints->flags = StateHint | InputHint ;
}
if ((class_hints = XAllocClassHint()) != NULL) {
class_hints->res_name = res_name;
class_hints->res_class = res_class;
}
XSetWMProperties(display, window, pWindowName, pIconName, NULL, 0,
size_hints, wm_hints, class_hints);
if (pWindowName)
XFree(pWindowName->value);
if (pIconName)
XFree(pIconName->value);
if (size_hints)
XFree(size_hints);
if (wm_hints)
XFree(wm_hints);
if (class_hints)
XFree(class_hints);
XMapWindow(display, window);
gc = XCreateGC(display, window, 0, &gcvalues);
have_gc = TRUE;
if (depth == 24 || depth == 32) {
bg_pixel = ((ulg)bg_red << RShift) |
((ulg)bg_green << GShift) |
((ulg)bg_blue << BShift);
} else if (depth == 16) {
bg_pixel = ((((ulg)bg_red << 8) >> RShift) & RMask) |
((((ulg)bg_green << 8) >> GShift) & GMask) |
((((ulg)bg_blue << 8) >> BShift) & BMask);
} else {
}
XSetForeground(display, gc, bg_pixel);
XFillRectangle(display, window, gc, 0, 0, image_width, image_height);
do
XNextEvent(display, &e);
while (e.type != Expose || e.xexpose.count);
XFlush(display);
if (depth == 24 || depth == 32) {
xdata = (uch *)malloc(4*image_width*image_height);
pad = 32;
} else if (depth == 16) {
xdata = (uch *)malloc(2*image_width*image_height);
pad = 16;
} else {
xdata = (uch *)malloc(image_width*image_height);
pad = 8;
}
if (!xdata) {
fprintf(stderr, PROGNAME ": unable to allocate image memory\n");
return 4;
}
ximage = XCreateImage(display, visual, depth, ZPixmap, 0,
(char *)xdata, image_width, image_height, pad, 0);
if (!ximage) {
fprintf(stderr, PROGNAME ": XCreateImage() failed\n");
free(xdata);
return 3;
}
ximage->byte_order = MSBFirst;
return 0;
}
static int rpng_x_display_image(void)
{
uch *src;
char *dest;
uch r, g, b, a;
ulg i, row, lastrow = 0;
ulg pixel;
int ximage_rowbytes = ximage->bytes_per_line;
Trace((stderr, "beginning display loop (image_channels == %d)\n",
image_channels))
Trace((stderr, " (width = %ld, rowbytes = %ld, ximage_rowbytes = %d)\n",
image_width, image_rowbytes, ximage_rowbytes))
Trace((stderr, " (bpp = %d)\n", ximage->bits_per_pixel))
Trace((stderr, " (byte_order = %s)\n", ximage->byte_order == MSBFirst?
"MSBFirst" : (ximage->byte_order == LSBFirst? "LSBFirst" : "unknown")))
if (depth == 24 || depth == 32) {
ulg red, green, blue;
for (lastrow = row = 0; row < image_height; ++row) {
src = image_data + row*image_rowbytes;
dest = ximage->data + row*ximage_rowbytes;
if (image_channels == 3) {
for (i = image_width; i > 0; --i) {
red = *src++;
green = *src++;
blue = *src++;
#ifdef NO_24BIT_MASKS
pixel = (red << RShift) |
(green << GShift) |
(blue << BShift);
*dest++ = (char)((pixel >> 24) & 0xff);
*dest++ = (char)((pixel >> 16) & 0xff);
*dest++ = (char)((pixel >> 8) & 0xff);
*dest++ = (char)( pixel & 0xff);
#else
red = (RShift < 0)? red << (-RShift) : red >> RShift;
green = (GShift < 0)? green << (-GShift) : green >> GShift;
blue = (BShift < 0)? blue << (-BShift) : blue >> BShift;
pixel = (red & RMask) | (green & GMask) | (blue & BMask);
*dest++ = (char)((pixel >> 24) & 0xff);
*dest++ = (char)((pixel >> 16) & 0xff);
*dest++ = (char)((pixel >> 8) & 0xff);
*dest++ = (char)( pixel & 0xff);
#endif
}
} else {
for (i = image_width; i > 0; --i) {
r = *src++;
g = *src++;
b = *src++;
a = *src++;
if (a == 255) {
red = r;
green = g;
blue = b;
} else if (a == 0) {
red = bg_red;
green = bg_green;
blue = bg_blue;
} else {
alpha_composite(red, r, a, bg_red);
alpha_composite(green, g, a, bg_green);
alpha_composite(blue, b, a, bg_blue);
}
pixel = (red << RShift) |
(green << GShift) |
(blue << BShift);
*dest++ = (char)((pixel >> 24) & 0xff);
*dest++ = (char)((pixel >> 16) & 0xff);
*dest++ = (char)((pixel >> 8) & 0xff);
*dest++ = (char)( pixel & 0xff);
}
}
if (((row+1) & 0xf) == 0) {
XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
(int)lastrow, image_width, 16);
XFlush(display);
lastrow = row + 1;
}
}
} else if (depth == 16) {
ush red, green, blue;
for (lastrow = row = 0; row < image_height; ++row) {
src = image_data + row*image_rowbytes;
dest = ximage->data + row*ximage_rowbytes;
if (image_channels == 3) {
for (i = image_width; i > 0; --i) {
red = ((ush)(*src) << 8);
++src;
green = ((ush)(*src) << 8);
++src;
blue = ((ush)(*src) << 8);
++src;
pixel = ((red >> RShift) & RMask) |
((green >> GShift) & GMask) |
((blue >> BShift) & BMask);
*dest++ = (char)((pixel >> 8) & 0xff);
*dest++ = (char)( pixel & 0xff);
}
} else {
for (i = image_width; i > 0; --i) {
r = *src++;
g = *src++;
b = *src++;
a = *src++;
if (a == 255) {
red = ((ush)r << 8);
green = ((ush)g << 8);
blue = ((ush)b << 8);
} else if (a == 0) {
red = ((ush)bg_red << 8);
green = ((ush)bg_green << 8);
blue = ((ush)bg_blue << 8);
} else {
alpha_composite(r, r, a, bg_red);
alpha_composite(g, g, a, bg_green);
alpha_composite(b, b, a, bg_blue);
red = ((ush)r << 8);
green = ((ush)g << 8);
blue = ((ush)b << 8);
}
pixel = ((red >> RShift) & RMask) |
((green >> GShift) & GMask) |
((blue >> BShift) & BMask);
*dest++ = (char)((pixel >> 8) & 0xff);
*dest++ = (char)( pixel & 0xff);
}
}
if (((row+1) & 0xf) == 0) {
XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
(int)lastrow, image_width, 16);
XFlush(display);
lastrow = row + 1;
}
}
} else {
}
Trace((stderr, "calling final XPutImage()\n"))
if (lastrow < image_height) {
XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
(int)lastrow, image_width, image_height-lastrow);
XFlush(display);
}
return 0;
}
static void rpng_x_cleanup(void)
{
if (image_data) {
free(image_data);
image_data = NULL;
}
if (ximage) {
if (ximage->data) {
free(ximage->data);
ximage->data = (char *)NULL;
}
XDestroyImage(ximage);
ximage = NULL;
}
if (have_gc)
XFreeGC(display, gc);
if (have_window)
XDestroyWindow(display, window);
if (have_colormap)
XFreeColormap(display, colormap);
if (have_nondefault_visual)
XFree(visual_list);
}
static int rpng_x_msb(ulg u32val)
{
int i;
for (i = 31; i >= 0; --i) {
if (u32val & 0x80000000L)
break;
u32val <<= 1;
}
return i;
}