// // "$Id: fl_read_image.cxx 6616 2009-01-01 21:28:26Z matt $" // // X11 image reading routines for the Fast Light Tool Kit (FLTK). // // Copyright 1998-2009 by Bill Spitzak and others. // // This library is free software; you can redistribute it and/or // modify it under the terms of the GNU Library General Public // License as published by the Free Software Foundation; either // version 2 of the License, or (at your option) any later version. // // This library 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 // Library General Public License for more details. // // You should have received a copy of the GNU Library General Public // License along with this library; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 // USA. // // Please report all bugs and problems on the following page: // // http://www.fltk.org/str.php // #include #include #include #include "flstring.h" #ifdef DEBUG # include #endif // DEBUG #ifdef WIN32 # include "fl_read_image_win32.cxx" #elif defined(__APPLE__) # include "fl_read_image_mac.cxx" #else # include # ifdef __sgi # include # else # include # endif // __sgi // Defined in fl_color.cxx extern uchar fl_redmask, fl_greenmask, fl_bluemask; extern int fl_redshift, fl_greenshift, fl_blueshift, fl_extrashift; // // 'fl_subimage_offsets()' - Calculate subimage offsets for an axis static inline int fl_subimage_offsets(int a, int aw, int b, int bw, int &obw) { int off; int ob; if (b >= a) { ob = b; off = 0; } else { ob = a; off = a - b; } bw -= off; if (ob + bw <= a + aw) { obw = bw; } else { obw = (a + aw) - ob; } return off; } // this handler will catch and ignore exceptions during XGetImage // to avoid an application crash static int xgetimageerrhandler(Display *display, XErrorEvent *error) { return 0; } // // 'fl_read_image()' - Read an image from the current window. // uchar * // O - Pixel buffer or NULL if failed fl_read_image(uchar *p, // I - Pixel buffer or NULL to allocate int X, // I - Left position int Y, // I - Top position int w, // I - Width of area to read int h, // I - Height of area to read int alpha) { // I - Alpha value for image (0 for none) XImage *image; // Captured image int i, maxindex; // Looping vars int x, y; // Current X & Y in image int d; // Depth of image unsigned char *line, // Array to hold image row *line_ptr; // Pointer to current line image unsigned char *pixel; // Current color value XColor colors[4096]; // Colors from the colormap... unsigned char cvals[4096][3]; // Color values from the colormap... unsigned index_mask, index_shift, red_mask, red_shift, green_mask, green_shift, blue_mask, blue_shift; // // Under X11 we have the option of the XGetImage() interface or SGI's // ReadDisplay extension which does all of the really hard work for // us... // # ifdef __sgi if (XReadDisplayQueryExtension(fl_display, &i, &i)) { image = XReadDisplay(fl_display, fl_window, X, Y, w, h, 0, NULL); } else # else image = 0; # endif // __sgi if (!image) { // fetch absolute coordinates int dx, dy, sx, sy, sw, sh; Window child_win; Fl_Window *win = fl_find(fl_window); if (win) { XTranslateCoordinates(fl_display, fl_window, RootWindow(fl_display, fl_screen), X, Y, &dx, &dy, &child_win); // screen dimensions Fl::screen_xywh(sx, sy, sw, sh, fl_screen); } if (!win || (dx >= sx && dy >= sy && dx + w <= sw && dy + h <= sh)) { // the image is fully contained, we can use the traditional method // however, if the window is obscured etc. the function will still fail. Make sure we // catch the error and continue, otherwise an exception will be thrown. XErrorHandler old_handler = XSetErrorHandler(xgetimageerrhandler); image = XGetImage(fl_display, fl_window, X, Y, w, h, AllPlanes, ZPixmap); XSetErrorHandler(old_handler); } else { // image is crossing borders, determine visible region int nw, nh, noffx, noffy; noffx = fl_subimage_offsets(sx, sw, dx, w, nw); noffy = fl_subimage_offsets(sy, sh, dy, h, nh); if (nw <= 0 || nh <= 0) return 0; // allocate the image int bpp = fl_visual->depth + ((fl_visual->depth / 8) % 2) * 8; char* buf = (char*)malloc(bpp / 8 * w * h); image = XCreateImage(fl_display, fl_visual->visual, fl_visual->depth, ZPixmap, 0, buf, w, h, bpp, 0); if (!image) { if (buf) free(buf); return 0; } XErrorHandler old_handler = XSetErrorHandler(xgetimageerrhandler); XImage *subimg = XGetSubImage(fl_display, fl_window, X + noffx, Y + noffy, nw, nh, AllPlanes, ZPixmap, image, noffx, noffy); XSetErrorHandler(old_handler); if (!subimg) { XDestroyImage(image); return 0; } } } if (!image) return 0; #ifdef DEBUG printf("width = %d\n", image->width); printf("height = %d\n", image->height); printf("xoffset = %d\n", image->xoffset); printf("format = %d\n", image->format); printf("data = %p\n", image->data); printf("byte_order = %d\n", image->byte_order); printf("bitmap_unit = %d\n", image->bitmap_unit); printf("bitmap_bit_order = %d\n", image->bitmap_bit_order); printf("bitmap_pad = %d\n", image->bitmap_pad); printf("depth = %d\n", image->depth); printf("bytes_per_line = %d\n", image->bytes_per_line); printf("bits_per_pixel = %d\n", image->bits_per_pixel); printf("red_mask = %08x\n", image->red_mask); printf("green_mask = %08x\n", image->green_mask); printf("blue_mask = %08x\n", image->blue_mask); printf("map_entries = %d\n", fl_visual->visual->map_entries); #endif // DEBUG d = alpha ? 4 : 3; // Allocate the image data array as needed... if (!p) p = new uchar[w * h * d]; // Initialize the default colors/alpha in the whole image... memset(p, alpha, w * h * d); // Check that we have valid mask/shift values... if (!image->red_mask && image->bits_per_pixel > 12) { // Greater than 12 bits must be TrueColor... image->red_mask = fl_visual->visual->red_mask; image->green_mask = fl_visual->visual->green_mask; image->blue_mask = fl_visual->visual->blue_mask; #ifdef DEBUG puts("\n---- UPDATED ----"); printf("fl_redmask = %08x\n", fl_redmask); printf("fl_redshift = %d\n", fl_redshift); printf("fl_greenmask = %08x\n", fl_greenmask); printf("fl_greenshift = %d\n", fl_greenshift); printf("fl_bluemask = %08x\n", fl_bluemask); printf("fl_blueshift = %d\n", fl_blueshift); printf("red_mask = %08x\n", image->red_mask); printf("green_mask = %08x\n", image->green_mask); printf("blue_mask = %08x\n", image->blue_mask); #endif // DEBUG } // Check if we have colormap image... if (!image->red_mask) { // Get the colormap entries for this window... maxindex = fl_visual->visual->map_entries; for (i = 0; i < maxindex; i ++) colors[i].pixel = i; XQueryColors(fl_display, fl_colormap, colors, maxindex); for (i = 0; i < maxindex; i ++) { cvals[i][0] = colors[i].red >> 8; cvals[i][1] = colors[i].green >> 8; cvals[i][2] = colors[i].blue >> 8; } // Read the pixels and output an RGB image... for (y = 0; y < image->height; y ++) { pixel = (unsigned char *)(image->data + y * image->bytes_per_line); line = p + y * w * d; switch (image->bits_per_pixel) { case 1 : for (x = image->width, line_ptr = line, index_mask = 128; x > 0; x --, line_ptr += d) { if (*pixel & index_mask) { line_ptr[0] = cvals[1][0]; line_ptr[1] = cvals[1][1]; line_ptr[2] = cvals[1][2]; } else { line_ptr[0] = cvals[0][0]; line_ptr[1] = cvals[0][1]; line_ptr[2] = cvals[0][2]; } if (index_mask > 1) { index_mask >>= 1; } else { index_mask = 128; pixel ++; } } break; case 2 : for (x = image->width, line_ptr = line, index_shift = 6; x > 0; x --, line_ptr += d) { i = (*pixel >> index_shift) & 3; line_ptr[0] = cvals[i][0]; line_ptr[1] = cvals[i][1]; line_ptr[2] = cvals[i][2]; if (index_shift > 0) { index_mask >>= 2; index_shift -= 2; } else { index_mask = 192; index_shift = 6; pixel ++; } } break; case 4 : for (x = image->width, line_ptr = line, index_shift = 4; x > 0; x --, line_ptr += d) { if (index_shift == 4) i = (*pixel >> 4) & 15; else i = *pixel & 15; line_ptr[0] = cvals[i][0]; line_ptr[1] = cvals[i][1]; line_ptr[2] = cvals[i][2]; if (index_shift > 0) { index_shift = 0; } else { index_shift = 4; pixel ++; } } break; case 8 : for (x = image->width, line_ptr = line; x > 0; x --, line_ptr += d, pixel ++) { line_ptr[0] = cvals[*pixel][0]; line_ptr[1] = cvals[*pixel][1]; line_ptr[2] = cvals[*pixel][2]; } break; case 12 : for (x = image->width, line_ptr = line, index_shift = 0; x > 0; x --, line_ptr += d) { if (index_shift == 0) { i = ((pixel[0] << 4) | (pixel[1] >> 4)) & 4095; } else { i = ((pixel[1] << 8) | pixel[2]) & 4095; } line_ptr[0] = cvals[i][0]; line_ptr[1] = cvals[i][1]; line_ptr[2] = cvals[i][2]; if (index_shift == 0) { index_shift = 4; } else { index_shift = 0; pixel += 3; } } break; } } } else { // RGB(A) image, so figure out the shifts & masks... red_mask = image->red_mask; red_shift = 0; while ((red_mask & 1) == 0) { red_mask >>= 1; red_shift ++; } green_mask = image->green_mask; green_shift = 0; while ((green_mask & 1) == 0) { green_mask >>= 1; green_shift ++; } blue_mask = image->blue_mask; blue_shift = 0; while ((blue_mask & 1) == 0) { blue_mask >>= 1; blue_shift ++; } // Read the pixels and output an RGB image... for (y = 0; y < image->height; y ++) { pixel = (unsigned char *)(image->data + y * image->bytes_per_line); line = p + y * w * d; switch (image->bits_per_pixel) { case 8 : for (x = image->width, line_ptr = line; x > 0; x --, line_ptr += d, pixel ++) { i = *pixel; line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask; line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask; line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask; } break; case 12 : for (x = image->width, line_ptr = line, index_shift = 0; x > 0; x --, line_ptr += d) { if (index_shift == 0) { i = ((pixel[0] << 4) | (pixel[1] >> 4)) & 4095; } else { i = ((pixel[1] << 8) | pixel[2]) & 4095; } line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask; line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask; line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask; if (index_shift == 0) { index_shift = 4; } else { index_shift = 0; pixel += 3; } } break; case 16 : if (image->byte_order == LSBFirst) { // Little-endian... for (x = image->width, line_ptr = line; x > 0; x --, line_ptr += d, pixel += 2) { i = (pixel[1] << 8) | pixel[0]; line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask; line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask; line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask; } } else { // Big-endian... for (x = image->width, line_ptr = line; x > 0; x --, line_ptr += d, pixel += 2) { i = (pixel[0] << 8) | pixel[1]; line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask; line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask; line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask; } } break; case 24 : if (image->byte_order == LSBFirst) { // Little-endian... for (x = image->width, line_ptr = line; x > 0; x --, line_ptr += d, pixel += 3) { i = (((pixel[2] << 8) | pixel[1]) << 8) | pixel[0]; line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask; line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask; line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask; } } else { // Big-endian... for (x = image->width, line_ptr = line; x > 0; x --, line_ptr += d, pixel += 3) { i = (((pixel[0] << 8) | pixel[1]) << 8) | pixel[2]; line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask; line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask; line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask; } } break; case 32 : if (image->byte_order == LSBFirst) { // Little-endian... for (x = image->width, line_ptr = line; x > 0; x --, line_ptr += d, pixel += 4) { i = (((((pixel[3] << 8) | pixel[2]) << 8) | pixel[1]) << 8) | pixel[0]; line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask; line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask; line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask; } } else { // Big-endian... for (x = image->width, line_ptr = line; x > 0; x --, line_ptr += d, pixel += 4) { i = (((((pixel[0] << 8) | pixel[1]) << 8) | pixel[2]) << 8) | pixel[3]; line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask; line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask; line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask; } } break; } } } // Destroy the X image we've read and return the RGB(A) image... XDestroyImage(image); return p; } #endif // // End of "$Id: fl_read_image.cxx 6616 2009-01-01 21:28:26Z matt $". //