736 lines
24 KiB
C
736 lines
24 KiB
C
/*---------------------------------------------------------------------------
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rpng - simple PNG display program rpng-win.c
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This program decodes and displays PNG images, with gamma correction and
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optionally with a user-specified background color (in case the image has
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transparency). It is very nearly the most basic PNG viewer possible.
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This version is for 32-bit Windows; it may compile under 16-bit Windows
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with a little tweaking (or maybe not).
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to do:
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- handle quoted command-line args (especially filenames with spaces)
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- have minimum window width: oh well
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- use %.1023s to simplify truncation of title-bar string?
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---------------------------------------------------------------------------
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Changelog:
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- 1.00: initial public release
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- 1.01: modified to allow abbreviated options; fixed long/ulong mis-
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match; switched to png_jmpbuf() macro
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- 1.02: added extra set of parentheses to png_jmpbuf() macro; fixed
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command-line parsing bug
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- 1.10: enabled "message window"/console (thanks to David Geldreich)
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- 2.00: dual-licensed (added GNU GPL)
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- 2.01: fixed improper display of usage screen on PNG error(s)
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- 2.02: check for integer overflow (Glenn R-P)
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---------------------------------------------------------------------------
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Copyright (c) 1998-2008, 2017 Greg Roelofs. All rights reserved.
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This software is provided "as is," without warranty of any kind,
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express or implied. In no event shall the author or contributors
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be held liable for any damages arising in any way from the use of
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this software.
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The contents of this file are DUAL-LICENSED. You may modify and/or
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redistribute this software according to the terms of one of the
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following two licenses (at your option):
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LICENSE 1 ("BSD-like with advertising clause"):
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute
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it freely, subject to the following restrictions:
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1. Redistributions of source code must retain the above copyright
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notice, disclaimer, and this list of conditions.
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2. Redistributions in binary form must reproduce the above copyright
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notice, disclaimer, and this list of conditions in the documenta-
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tion and/or other materials provided with the distribution.
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3. All advertising materials mentioning features or use of this
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software must display the following acknowledgment:
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This product includes software developed by Greg Roelofs
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and contributors for the book, "PNG: The Definitive Guide,"
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published by O'Reilly and Associates.
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LICENSE 2 (GNU GPL v2 or later):
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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---------------------------------------------------------------------------*/
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#define PROGNAME "rpng-win"
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#define LONGNAME "Simple PNG Viewer for Windows"
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#define VERSION "2.01 of 16 March 2008"
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <time.h>
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#include <windows.h>
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#ifdef __CYGWIN__
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/* getch replacement. Turns out, we don't really need this,
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* but leave it here if we ever enable any of the uses of
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* _getch in the main code
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*/
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#include <unistd.h>
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#include <termio.h>
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#include <sys/ioctl.h>
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int repl_getch( void )
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{
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char ch;
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int fd = fileno(stdin);
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struct termio old_tty, new_tty;
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ioctl(fd, TCGETA, &old_tty);
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new_tty = old_tty;
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new_tty.c_lflag &= ~(ICANON | ECHO | ISIG);
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ioctl(fd, TCSETA, &new_tty);
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fread(&ch, 1, sizeof(ch), stdin);
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ioctl(fd, TCSETA, &old_tty);
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return ch;
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}
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#define _getch repl_getch
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#else
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#include <conio.h> /* only for _getch() */
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#endif
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/* #define DEBUG : this enables the Trace() macros */
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#include "readpng.h" /* typedefs, common macros, readpng prototypes */
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/* could just include png.h, but this macro is the only thing we need
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* (name and typedefs changed to local versions); note that side effects
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* only happen with alpha (which could easily be avoided with
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* "ush acopy = (alpha);") */
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#define alpha_composite(composite, fg, alpha, bg) { \
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ush temp = ((ush)(fg)*(ush)(alpha) + \
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(ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128); \
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(composite) = (uch)((temp + (temp >> 8)) >> 8); \
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}
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/* local prototypes */
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static int rpng_win_create_window(HINSTANCE hInst, int showmode);
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static int rpng_win_display_image(void);
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static void rpng_win_cleanup(void);
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LRESULT CALLBACK rpng_win_wndproc(HWND, UINT, WPARAM, LPARAM);
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static char titlebar[1024];
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static char *progname = PROGNAME;
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static char *appname = LONGNAME;
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static char *filename;
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static FILE *infile;
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static char *bgstr;
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static uch bg_red=0, bg_green=0, bg_blue=0;
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static double display_exponent;
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static ulg image_width, image_height, image_rowbytes;
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static int image_channels;
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static uch *image_data;
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/* Windows-specific variables */
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static ulg wimage_rowbytes;
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static uch *dib;
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static uch *wimage_data;
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static BITMAPINFOHEADER *bmih;
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static HWND global_hwnd;
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int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
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{
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char *args[1024]; /* arbitrary limit, but should suffice */
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char *p, *q, **argv = args;
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int argc = 0;
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int rc, alen, flen;
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int error = 0;
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int have_bg = FALSE;
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double LUT_exponent; /* just the lookup table */
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double CRT_exponent = 2.2; /* just the monitor */
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double default_display_exponent; /* whole display system */
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MSG msg;
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filename = (char *)NULL;
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#ifndef __CYGWIN__
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/* First reenable console output, which normally goes to the bit bucket
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* for windowed apps. Closing the console window will terminate the
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* app. Thanks to David.Geldreich at realviz.com for supplying the magical
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* incantation. */
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AllocConsole();
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freopen("CONOUT$", "a", stderr);
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freopen("CONOUT$", "a", stdout);
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#endif
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/* Next set the default value for our display-system exponent, i.e.,
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* the product of the CRT exponent and the exponent corresponding to
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* the frame-buffer's lookup table (LUT), if any. This is not an
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* exhaustive list of LUT values (e.g., OpenStep has a lot of weird
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* ones), but it should cover 99% of the current possibilities. And
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* yes, these ifdefs are completely wasted in a Windows program... */
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#if defined(NeXT)
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LUT_exponent = 1.0 / 2.2;
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/*
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if (some_next_function_that_returns_gamma(&next_gamma))
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LUT_exponent = 1.0 / next_gamma;
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*/
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#elif defined(sgi)
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LUT_exponent = 1.0 / 1.7;
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/* there doesn't seem to be any documented function to get the
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* "gamma" value, so we do it the hard way */
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infile = fopen("/etc/config/system.glGammaVal", "r");
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if (infile) {
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double sgi_gamma;
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fgets(tmpline, 80, infile);
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fclose(infile);
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sgi_gamma = atof(tmpline);
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if (sgi_gamma > 0.0)
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LUT_exponent = 1.0 / sgi_gamma;
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}
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#elif defined(Macintosh)
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LUT_exponent = 1.8 / 2.61;
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/*
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if (some_mac_function_that_returns_gamma(&mac_gamma))
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LUT_exponent = mac_gamma / 2.61;
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*/
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#else
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LUT_exponent = 1.0; /* assume no LUT: most PCs */
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#endif
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/* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
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default_display_exponent = LUT_exponent * CRT_exponent;
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/* If the user has set the SCREEN_GAMMA environment variable as suggested
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* (somewhat imprecisely) in the libpng documentation, use that; otherwise
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* use the default value we just calculated. Either way, the user may
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* override this via a command-line option. */
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if ((p = getenv("SCREEN_GAMMA")) != NULL)
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display_exponent = atof(p);
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else
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display_exponent = default_display_exponent;
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/* Windows really hates command lines, so we have to set up our own argv.
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* Note that we do NOT bother with quoted arguments here, so don't use
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* filenames with spaces in 'em! */
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argv[argc++] = PROGNAME;
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p = cmd;
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for (;;) {
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if (*p == ' ')
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while (*++p == ' ')
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;
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/* now p points at the first non-space after some spaces */
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if (*p == '\0')
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break; /* nothing after the spaces: done */
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argv[argc++] = q = p;
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while (*q && *q != ' ')
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++q;
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/* now q points at a space or the end of the string */
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if (*q == '\0')
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break; /* last argv already terminated; quit */
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*q = '\0'; /* change space to terminator */
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p = q + 1;
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}
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argv[argc] = NULL; /* terminate the argv array itself */
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/* Now parse the command line for options and the PNG filename. */
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while (*++argv && !error) {
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if (!strncmp(*argv, "-gamma", 2)) {
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if (!*++argv)
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++error;
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else {
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display_exponent = atof(*argv);
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if (display_exponent <= 0.0)
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++error;
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}
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} else if (!strncmp(*argv, "-bgcolor", 2)) {
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if (!*++argv)
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++error;
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else {
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bgstr = *argv;
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if (strlen(bgstr) != 7 || bgstr[0] != '#')
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++error;
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else
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have_bg = TRUE;
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}
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} else {
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if (**argv != '-') {
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filename = *argv;
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if (argv[1]) /* shouldn't be any more args after filename */
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++error;
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} else
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++error; /* not expecting any other options */
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}
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}
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if (!filename)
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++error;
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/* print usage screen if any errors up to this point */
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if (error) {
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#ifndef __CYGWIN__
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int ch;
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#endif
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fprintf(stderr, "\n%s %s: %s\n\n", PROGNAME, VERSION, appname);
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readpng_version_info();
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fprintf(stderr, "\n"
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"Usage: %s [-gamma exp] [-bgcolor bg] file.png\n"
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" exp \ttransfer-function exponent (``gamma'') of the display\n"
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"\t\t system in floating-point format (e.g., ``%.1f''); equal\n"
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"\t\t to the product of the lookup-table exponent (varies)\n"
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"\t\t and the CRT exponent (usually 2.2); must be positive\n"
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" bg \tdesired background color in 7-character hex RGB format\n"
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"\t\t (e.g., ``#ff7700'' for orange: same as HTML colors);\n"
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"\t\t used with transparent images\n"
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"\nPress Q, Esc or mouse button 1 after image is displayed to quit.\n"
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#ifndef __CYGWIN__
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"Press Q or Esc to quit this usage screen.\n"
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#endif
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"\n", PROGNAME, default_display_exponent);
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#ifndef __CYGWIN__
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do
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ch = _getch();
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while (ch != 'q' && ch != 'Q' && ch != 0x1B);
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#endif
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exit(1);
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}
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if (!(infile = fopen(filename, "rb"))) {
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fprintf(stderr, PROGNAME ": can't open PNG file [%s]\n", filename);
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++error;
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} else {
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if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
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switch (rc) {
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case 1:
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fprintf(stderr, PROGNAME
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": [%s] is not a PNG file: incorrect signature\n",
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filename);
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break;
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case 2:
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fprintf(stderr, PROGNAME
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": [%s] has bad IHDR (libpng longjmp)\n", filename);
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break;
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case 4:
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fprintf(stderr, PROGNAME ": insufficient memory\n");
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break;
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default:
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fprintf(stderr, PROGNAME
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": unknown readpng_init() error\n");
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break;
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}
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++error;
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}
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if (error)
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fclose(infile);
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}
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if (error) {
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#ifndef __CYGWIN__
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int ch;
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#endif
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fprintf(stderr, PROGNAME ": aborting.\n");
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#ifndef __CYGWIN__
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do
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ch = _getch();
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while (ch != 'q' && ch != 'Q' && ch != 0x1B);
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#endif
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exit(2);
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} else {
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fprintf(stderr, "\n%s %s: %s\n", PROGNAME, VERSION, appname);
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#ifndef __CYGWIN__
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fprintf(stderr,
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"\n [console window: closing this window will terminate %s]\n\n",
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PROGNAME);
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#endif
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}
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/* set the title-bar string, but make sure buffer doesn't overflow */
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alen = strlen(appname);
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flen = strlen(filename);
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if (alen + flen + 3 > 1023)
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sprintf(titlebar, "%s: ...%s", appname, filename+(alen+flen+6-1023));
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else
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sprintf(titlebar, "%s: %s", appname, filename);
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/* if the user didn't specify a background color on the command line,
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* check for one in the PNG file--if not, the initialized values of 0
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* (black) will be used */
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if (have_bg) {
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unsigned r, g, b; /* this approach quiets compiler warnings */
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sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
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bg_red = (uch)r;
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bg_green = (uch)g;
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bg_blue = (uch)b;
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} else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
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readpng_cleanup(TRUE);
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fprintf(stderr, PROGNAME
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": libpng error while checking for background color\n");
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exit(2);
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}
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/* do the basic Windows initialization stuff, make the window and fill it
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* with the background color */
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if (rpng_win_create_window(hInst, showmode))
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exit(2);
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/* decode the image, all at once */
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Trace((stderr, "calling readpng_get_image()\n"))
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image_data = readpng_get_image(display_exponent, &image_channels,
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&image_rowbytes);
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Trace((stderr, "done with readpng_get_image()\n"))
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/* done with PNG file, so clean up to minimize memory usage (but do NOT
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* nuke image_data!) */
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readpng_cleanup(FALSE);
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fclose(infile);
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if (!image_data) {
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fprintf(stderr, PROGNAME ": unable to decode PNG image\n");
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exit(3);
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}
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/* display image (composite with background if requested) */
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Trace((stderr, "calling rpng_win_display_image()\n"))
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if (rpng_win_display_image()) {
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free(image_data);
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exit(4);
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}
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Trace((stderr, "done with rpng_win_display_image()\n"))
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|
|
|
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/* wait for the user to tell us when to quit */
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printf(
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#ifndef __CYGWIN__
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"Done. Press Q, Esc or mouse button 1 (within image window) to quit.\n"
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#else
|
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"Done. Press mouse button 1 (within image window) to quit.\n"
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#endif
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);
|
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fflush(stdout);
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|
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while (GetMessage(&msg, NULL, 0, 0)) {
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TranslateMessage(&msg);
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DispatchMessage(&msg);
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}
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|
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|
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/* OK, we're done: clean up all image and Windows resources and go away */
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|
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rpng_win_cleanup();
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|
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return msg.wParam;
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}
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|
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static int rpng_win_create_window(HINSTANCE hInst, int showmode)
|
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{
|
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uch *dest;
|
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int extra_width, extra_height;
|
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ulg i, j;
|
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WNDCLASSEX wndclass;
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|
|
|
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/*---------------------------------------------------------------------------
|
|
Allocate memory for the display-specific version of the image (round up
|
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to multiple of 4 for Windows DIB).
|
|
---------------------------------------------------------------------------*/
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|
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wimage_rowbytes = ((3*image_width + 3L) >> 2) << 2;
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|
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/* Guard against integer overflow */
|
|
if (image_height > ((size_t)(-1))/wimage_rowbytes) {
|
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fprintf(stderr, PROGNAME ": image_data buffer would be too large\n");
|
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return 4; /* fail */
|
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}
|
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|
|
if (!(dib = (uch *)malloc(sizeof(BITMAPINFOHEADER) +
|
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wimage_rowbytes*image_height)))
|
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{
|
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return 4; /* fail */
|
|
}
|
|
|
|
/*---------------------------------------------------------------------------
|
|
Initialize the DIB. Negative height means to use top-down BMP ordering
|
|
(must be uncompressed, but that's what we want). Bit count of 1, 4 or 8
|
|
implies a colormap of RGBX quads, but 24-bit BMPs just use B,G,R values
|
|
directly => wimage_data begins immediately after BMP header.
|
|
---------------------------------------------------------------------------*/
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|
|
memset(dib, 0, sizeof(BITMAPINFOHEADER));
|
|
bmih = (BITMAPINFOHEADER *)dib;
|
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bmih->biSize = sizeof(BITMAPINFOHEADER);
|
|
bmih->biWidth = image_width;
|
|
bmih->biHeight = -((long)image_height);
|
|
bmih->biPlanes = 1;
|
|
bmih->biBitCount = 24;
|
|
bmih->biCompression = 0;
|
|
wimage_data = dib + sizeof(BITMAPINFOHEADER);
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|
|
|
/*---------------------------------------------------------------------------
|
|
Fill in background color (black by default); data are in BGR order.
|
|
---------------------------------------------------------------------------*/
|
|
|
|
for (j = 0; j < image_height; ++j) {
|
|
dest = wimage_data + j*wimage_rowbytes;
|
|
for (i = image_width; i > 0; --i) {
|
|
*dest++ = bg_blue;
|
|
*dest++ = bg_green;
|
|
*dest++ = bg_red;
|
|
}
|
|
}
|
|
|
|
/*---------------------------------------------------------------------------
|
|
Set the window parameters.
|
|
---------------------------------------------------------------------------*/
|
|
|
|
memset(&wndclass, 0, sizeof(wndclass));
|
|
|
|
wndclass.cbSize = sizeof(wndclass);
|
|
wndclass.style = CS_HREDRAW | CS_VREDRAW;
|
|
wndclass.lpfnWndProc = rpng_win_wndproc;
|
|
wndclass.hInstance = hInst;
|
|
wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
|
|
wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
|
|
wndclass.hbrBackground = (HBRUSH)GetStockObject(DKGRAY_BRUSH);
|
|
wndclass.lpszMenuName = NULL;
|
|
wndclass.lpszClassName = progname;
|
|
wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
|
|
|
|
RegisterClassEx(&wndclass);
|
|
|
|
/*---------------------------------------------------------------------------
|
|
Finally, create the window.
|
|
---------------------------------------------------------------------------*/
|
|
|
|
extra_width = 2*(GetSystemMetrics(SM_CXBORDER) +
|
|
GetSystemMetrics(SM_CXDLGFRAME));
|
|
extra_height = 2*(GetSystemMetrics(SM_CYBORDER) +
|
|
GetSystemMetrics(SM_CYDLGFRAME)) +
|
|
GetSystemMetrics(SM_CYCAPTION);
|
|
|
|
global_hwnd = CreateWindow(progname, titlebar, WS_OVERLAPPEDWINDOW,
|
|
CW_USEDEFAULT, CW_USEDEFAULT, image_width+extra_width,
|
|
image_height+extra_height, NULL, NULL, hInst, NULL);
|
|
|
|
ShowWindow(global_hwnd, showmode);
|
|
UpdateWindow(global_hwnd);
|
|
|
|
return 0;
|
|
|
|
} /* end function rpng_win_create_window() */
|
|
|
|
|
|
|
|
|
|
|
|
static int rpng_win_display_image()
|
|
{
|
|
uch *src, *dest;
|
|
uch r, g, b, a;
|
|
ulg i, row, lastrow;
|
|
RECT rect;
|
|
|
|
|
|
Trace((stderr, "beginning display loop (image_channels == %d)\n",
|
|
image_channels))
|
|
Trace((stderr, "(width = %ld, rowbytes = %ld, wimage_rowbytes = %d)\n",
|
|
image_width, image_rowbytes, wimage_rowbytes))
|
|
|
|
|
|
/*---------------------------------------------------------------------------
|
|
Blast image data to buffer. This whole routine takes place before the
|
|
message loop begins, so there's no real point in any pseudo-progressive
|
|
display...
|
|
---------------------------------------------------------------------------*/
|
|
|
|
for (lastrow = row = 0; row < image_height; ++row) {
|
|
src = image_data + row*image_rowbytes;
|
|
dest = wimage_data + row*wimage_rowbytes;
|
|
if (image_channels == 3) {
|
|
for (i = image_width; i > 0; --i) {
|
|
r = *src++;
|
|
g = *src++;
|
|
b = *src++;
|
|
*dest++ = b;
|
|
*dest++ = g; /* note reverse order */
|
|
*dest++ = r;
|
|
}
|
|
} else /* if (image_channels == 4) */ {
|
|
for (i = image_width; i > 0; --i) {
|
|
r = *src++;
|
|
g = *src++;
|
|
b = *src++;
|
|
a = *src++;
|
|
if (a == 255) {
|
|
*dest++ = b;
|
|
*dest++ = g;
|
|
*dest++ = r;
|
|
} else if (a == 0) {
|
|
*dest++ = bg_blue;
|
|
*dest++ = bg_green;
|
|
*dest++ = bg_red;
|
|
} else {
|
|
/* this macro (copied from png.h) composites the
|
|
* foreground and background values and puts the
|
|
* result into the first argument; there are no
|
|
* side effects with the first argument */
|
|
alpha_composite(*dest++, b, a, bg_blue);
|
|
alpha_composite(*dest++, g, a, bg_green);
|
|
alpha_composite(*dest++, r, a, bg_red);
|
|
}
|
|
}
|
|
}
|
|
/* display after every 16 lines */
|
|
if (((row+1) & 0xf) == 0) {
|
|
rect.left = 0L;
|
|
rect.top = (LONG)lastrow;
|
|
rect.right = (LONG)image_width; /* possibly off by one? */
|
|
rect.bottom = (LONG)lastrow + 16L; /* possibly off by one? */
|
|
InvalidateRect(global_hwnd, &rect, FALSE);
|
|
UpdateWindow(global_hwnd); /* similar to XFlush() */
|
|
lastrow = row + 1;
|
|
}
|
|
}
|
|
|
|
Trace((stderr, "calling final image-flush routine\n"))
|
|
if (lastrow < image_height) {
|
|
rect.left = 0L;
|
|
rect.top = (LONG)lastrow;
|
|
rect.right = (LONG)image_width; /* possibly off by one? */
|
|
rect.bottom = (LONG)image_height; /* possibly off by one? */
|
|
InvalidateRect(global_hwnd, &rect, FALSE);
|
|
UpdateWindow(global_hwnd); /* similar to XFlush() */
|
|
}
|
|
|
|
/*
|
|
last param determines whether or not background is wiped before paint
|
|
InvalidateRect(global_hwnd, NULL, TRUE);
|
|
UpdateWindow(global_hwnd);
|
|
*/
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
static void rpng_win_cleanup()
|
|
{
|
|
if (image_data) {
|
|
free(image_data);
|
|
image_data = NULL;
|
|
}
|
|
|
|
if (dib) {
|
|
free(dib);
|
|
dib = NULL;
|
|
}
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
LRESULT CALLBACK rpng_win_wndproc(HWND hwnd, UINT iMsg, WPARAM wP, LPARAM lP)
|
|
{
|
|
HDC hdc;
|
|
PAINTSTRUCT ps;
|
|
int rc;
|
|
|
|
switch (iMsg) {
|
|
case WM_CREATE:
|
|
/* one-time processing here, if any */
|
|
return 0;
|
|
|
|
case WM_PAINT:
|
|
hdc = BeginPaint(hwnd, &ps);
|
|
/* dest */
|
|
rc = StretchDIBits(hdc, 0, 0, image_width, image_height,
|
|
/* source */
|
|
0, 0, image_width, image_height,
|
|
wimage_data, (BITMAPINFO *)bmih,
|
|
/* iUsage: no clue */
|
|
0, SRCCOPY);
|
|
EndPaint(hwnd, &ps);
|
|
return 0;
|
|
|
|
/* wait for the user to tell us when to quit */
|
|
case WM_CHAR:
|
|
switch (wP) { /* only need one, so ignore repeat count */
|
|
case 'q':
|
|
case 'Q':
|
|
case 0x1B: /* Esc key */
|
|
PostQuitMessage(0);
|
|
}
|
|
return 0;
|
|
|
|
case WM_LBUTTONDOWN: /* another way of quitting */
|
|
case WM_DESTROY:
|
|
PostQuitMessage(0);
|
|
return 0;
|
|
}
|
|
|
|
return DefWindowProc(hwnd, iMsg, wP, lP);
|
|
}
|