| /*--------------------------------------------------------------------------- |
| |
| rpng - simple PNG display program rpng-win.c |
| |
| This program decodes and displays PNG images, with gamma correction and |
| optionally with a user-specified background color (in case the image has |
| transparency). It is very nearly the most basic PNG viewer possible. |
| This version is for 32-bit Windows; it may compile under 16-bit Windows |
| with a little tweaking (or maybe not). |
| |
| to do: |
| - handle quoted command-line args (especially filenames with spaces) |
| - have minimum window width: oh well |
| - use %.1023s to simplify truncation of title-bar string? |
| |
| --------------------------------------------------------------------------- |
| |
| Changelog: |
| - 1.00: initial public release |
| - 1.01: modified to allow abbreviated options; fixed long/ulong mis- |
| match; switched to png_jmpbuf() macro |
| - 1.02: added extra set of parentheses to png_jmpbuf() macro; fixed |
| command-line parsing bug |
| - 1.10: enabled "message window"/console (thanks to David Geldreich) |
| - 2.00: dual-licensed (added GNU GPL) |
| - 2.01: fixed improper display of usage screen on PNG error(s) |
| |
| --------------------------------------------------------------------------- |
| |
| Copyright (c) 1998-2008 Greg Roelofs. All rights reserved. |
| |
| This software is provided "as is," without warranty of any kind, |
| express or implied. In no event shall the author or contributors |
| be held liable for any damages arising in any way from the use of |
| this software. |
| |
| The contents of this file are DUAL-LICENSED. You may modify and/or |
| redistribute this software according to the terms of one of the |
| following two licenses (at your option): |
| |
| |
| LICENSE 1 ("BSD-like with advertising clause"): |
| |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute |
| it freely, subject to the following restrictions: |
| |
| 1. Redistributions of source code must retain the above copyright |
| notice, disclaimer, and this list of conditions. |
| 2. Redistributions in binary form must reproduce the above copyright |
| notice, disclaimer, and this list of conditions in the documenta- |
| tion and/or other materials provided with the distribution. |
| 3. All advertising materials mentioning features or use of this |
| software must display the following acknowledgment: |
| |
| This product includes software developed by Greg Roelofs |
| and contributors for the book, "PNG: The Definitive Guide," |
| published by O'Reilly and Associates. |
| |
| |
| LICENSE 2 (GNU GPL v2 or later): |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software Foundation, |
| Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| |
| ---------------------------------------------------------------------------*/ |
| |
| #define PROGNAME "rpng-win" |
| #define LONGNAME "Simple PNG Viewer for Windows" |
| #define VERSION "2.01 of 16 March 2008" |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <time.h> |
| #include <windows.h> |
| #include <conio.h> /* only for _getch() */ |
| |
| /* #define DEBUG : this enables the Trace() macros */ |
| |
| #include "readpng.h" /* typedefs, common macros, readpng prototypes */ |
| |
| |
| /* could just include png.h, but this macro is the only thing we need |
| * (name and typedefs changed to local versions); note that side effects |
| * only happen with alpha (which could easily be avoided with |
| * "ush acopy = (alpha);") */ |
| |
| #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); \ |
| } |
| |
| |
| /* local prototypes */ |
| static int rpng_win_create_window(HINSTANCE hInst, int showmode); |
| static int rpng_win_display_image(void); |
| static void rpng_win_cleanup(void); |
| LRESULT CALLBACK rpng_win_wndproc(HWND, UINT, WPARAM, LPARAM); |
| |
| |
| static char titlebar[1024]; |
| static char *progname = PROGNAME; |
| static char *appname = LONGNAME; |
| 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; |
| |
| /* Windows-specific variables */ |
| static ulg wimage_rowbytes; |
| static uch *dib; |
| static uch *wimage_data; |
| static BITMAPINFOHEADER *bmih; |
| |
| static HWND global_hwnd; |
| |
| |
| |
| |
| int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode) |
| { |
| char *args[1024]; /* arbitrary limit, but should suffice */ |
| char *p, *q, **argv = args; |
| int argc = 0; |
| int rc, alen, flen; |
| int error = 0; |
| int have_bg = FALSE; |
| double LUT_exponent; /* just the lookup table */ |
| double CRT_exponent = 2.2; /* just the monitor */ |
| double default_display_exponent; /* whole display system */ |
| MSG msg; |
| |
| |
| filename = (char *)NULL; |
| |
| |
| /* First reenable console output, which normally goes to the bit bucket |
| * for windowed apps. Closing the console window will terminate the |
| * app. Thanks to David.Geldreich@realviz.com for supplying the magical |
| * incantation. */ |
| |
| AllocConsole(); |
| freopen("CONOUT$", "a", stderr); |
| freopen("CONOUT$", "a", stdout); |
| |
| |
| /* Next set the default value for our display-system exponent, i.e., |
| * the product of the CRT exponent and the exponent corresponding to |
| * the frame-buffer's lookup table (LUT), if any. This is not an |
| * exhaustive list of LUT values (e.g., OpenStep has a lot of weird |
| * ones), but it should cover 99% of the current possibilities. And |
| * yes, these ifdefs are completely wasted in a Windows program... */ |
| |
| #if defined(NeXT) |
| LUT_exponent = 1.0 / 2.2; |
| /* |
| if (some_next_function_that_returns_gamma(&next_gamma)) |
| LUT_exponent = 1.0 / next_gamma; |
| */ |
| #elif defined(sgi) |
| LUT_exponent = 1.0 / 1.7; |
| /* there doesn't seem to be any documented function to get the |
| * "gamma" value, so we do it the hard way */ |
| 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; |
| /* |
| if (some_mac_function_that_returns_gamma(&mac_gamma)) |
| LUT_exponent = mac_gamma / 2.61; |
| */ |
| #else |
| LUT_exponent = 1.0; /* assume no LUT: most PCs */ |
| #endif |
| |
| /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */ |
| default_display_exponent = LUT_exponent * CRT_exponent; |
| |
| |
| /* If the user has set the SCREEN_GAMMA environment variable as suggested |
| * (somewhat imprecisely) in the libpng documentation, use that; otherwise |
| * use the default value we just calculated. Either way, the user may |
| * override this via a command-line option. */ |
| |
| if ((p = getenv("SCREEN_GAMMA")) != NULL) |
| display_exponent = atof(p); |
| else |
| display_exponent = default_display_exponent; |
| |
| |
| /* Windows really hates command lines, so we have to set up our own argv. |
| * Note that we do NOT bother with quoted arguments here, so don't use |
| * filenames with spaces in 'em! */ |
| |
| argv[argc++] = PROGNAME; |
| p = cmd; |
| for (;;) { |
| if (*p == ' ') |
| while (*++p == ' ') |
| ; |
| /* now p points at the first non-space after some spaces */ |
| if (*p == '\0') |
| break; /* nothing after the spaces: done */ |
| argv[argc++] = q = p; |
| while (*q && *q != ' ') |
| ++q; |
| /* now q points at a space or the end of the string */ |
| if (*q == '\0') |
| break; /* last argv already terminated; quit */ |
| *q = '\0'; /* change space to terminator */ |
| p = q + 1; |
| } |
| argv[argc] = NULL; /* terminate the argv array itself */ |
| |
| |
| /* Now parse the command line for options and the PNG filename. */ |
| |
| while (*++argv && !error) { |
| 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]) /* shouldn't be any more args after filename */ |
| ++error; |
| } else |
| ++error; /* not expecting any other options */ |
| } |
| } |
| |
| if (!filename) |
| ++error; |
| |
| |
| /* print usage screen if any errors up to this point */ |
| |
| if (error) { |
| int ch; |
| |
| fprintf(stderr, "\n%s %s: %s\n\n", PROGNAME, VERSION, appname); |
| readpng_version_info(); |
| fprintf(stderr, "\n" |
| "Usage: %s [-gamma exp] [-bgcolor bg] file.png\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 after image is displayed to quit.\n" |
| "Press Q or Esc to quit this usage screen.\n" |
| "\n", PROGNAME, default_display_exponent); |
| do |
| ch = _getch(); |
| while (ch != 'q' && ch != 'Q' && ch != 0x1B); |
| 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; |
| } |
| if (error) |
| fclose(infile); |
| } |
| |
| |
| if (error) { |
| int ch; |
| |
| fprintf(stderr, PROGNAME ": aborting.\n"); |
| do |
| ch = _getch(); |
| while (ch != 'q' && ch != 'Q' && ch != 0x1B); |
| exit(2); |
| } else { |
| fprintf(stderr, "\n%s %s: %s\n", PROGNAME, VERSION, appname); |
| fprintf(stderr, |
| "\n [console window: closing this window will terminate %s]\n\n", |
| PROGNAME); |
| } |
| |
| |
| /* set the title-bar string, but make sure buffer doesn't overflow */ |
| |
| 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 the user didn't specify a background color on the command line, |
| * check for one in the PNG file--if not, the initialized values of 0 |
| * (black) will be used */ |
| |
| if (have_bg) { |
| unsigned r, g, b; /* this approach quiets compiler warnings */ |
| |
| 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); |
| } |
| |
| |
| /* do the basic Windows initialization stuff, make the window and fill it |
| * with the background color */ |
| |
| if (rpng_win_create_window(hInst, showmode)) |
| exit(2); |
| |
| |
| /* decode the image, all at once */ |
| |
| 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")) |
| |
| |
| /* done with PNG file, so clean up to minimize memory usage (but do NOT |
| * nuke image_data!) */ |
| |
| readpng_cleanup(FALSE); |
| fclose(infile); |
| |
| if (!image_data) { |
| fprintf(stderr, PROGNAME ": unable to decode PNG image\n"); |
| exit(3); |
| } |
| |
| |
| /* display image (composite with background if requested) */ |
| |
| Trace((stderr, "calling rpng_win_display_image()\n")) |
| if (rpng_win_display_image()) { |
| free(image_data); |
| exit(4); |
| } |
| Trace((stderr, "done with rpng_win_display_image()\n")) |
| |
| |
| /* wait for the user to tell us when to quit */ |
| |
| printf( |
| "Done. Press Q, Esc or mouse button 1 (within image window) to quit.\n"); |
| fflush(stdout); |
| |
| while (GetMessage(&msg, NULL, 0, 0)) { |
| TranslateMessage(&msg); |
| DispatchMessage(&msg); |
| } |
| |
| |
| /* OK, we're done: clean up all image and Windows resources and go away */ |
| |
| rpng_win_cleanup(); |
| |
| return msg.wParam; |
| } |
| |
| |
| |
| |
| |
| static int rpng_win_create_window(HINSTANCE hInst, int showmode) |
| { |
| uch *dest; |
| int extra_width, extra_height; |
| ulg i, j; |
| WNDCLASSEX wndclass; |
| |
| |
| /*--------------------------------------------------------------------------- |
| Allocate memory for the display-specific version of the image (round up |
| to multiple of 4 for Windows DIB). |
| ---------------------------------------------------------------------------*/ |
| |
| wimage_rowbytes = ((3*image_width + 3L) >> 2) << 2; |
| |
| if (!(dib = (uch *)malloc(sizeof(BITMAPINFOHEADER) + |
| wimage_rowbytes*image_height))) |
| { |
| 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. |
| ---------------------------------------------------------------------------*/ |
| |
| memset(dib, 0, sizeof(BITMAPINFOHEADER)); |
| bmih = (BITMAPINFOHEADER *)dib; |
| 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); |
| |
| /*--------------------------------------------------------------------------- |
| 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); |
| } |
