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--- c:graphics.h:getimage [2015/05/06 23:06]
+++ c:graphics.h:getimage [2024/02/16 01:05] (current)
@@ Line 1: / Line 1: @@
+===== getimage =====
+====Syntax of getimage ====
+ <code c>
+#include <graphics.h>
+void getimage(int left, int top, int right, int bottom, void *bitmap);
+  </code>
+==== Description of getimage ====
+<code c>
+getimage copies an image from the screen to memory.
+left, top, right, and bottom define the screen area to which the
+rectangle is copied. bitmap points to the area in memory where the bit
+image is stored. The first two words of this area are used for the width
+and height of the rectangle; the remainder holds the image itself.
+</code>
+==== Example of getimage ====
+<code c>
+/* getimage example */
+#include <graphics.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <conio.h>
+#include <alloc.h>
+void save_screen(void *buf[4]);
+void restore_screen(void *buf[4]);
+int maxx, maxy;
+int main(void)
+{
+   int gdriver=DETECT, gmode, errorcode;
+   void *ptr[4];
+   /* autodetect the graphics driver and mode */
+   initgraph(&gdriver, &gmode, "");
+   errorcode = graphresult();  /* check for any errors */
+   if (errorcode != grOk) {
+printf("Graphics error: %s\n", grapherrormsg(errorcode));
+printf("Press any key to halt:");
+getch();
+exit(1);
+   }
+   maxx = getmaxx();
+   maxy = getmaxy();
+   /* draw an image on the screen */
+   rectangle(0, 0, maxx, maxy);
+   line(0, 0, maxx, maxy);
+   line(0, maxy, maxx, 0);
+   save_screen(ptr);     /* save the current screen */
+   getch();  /* pause screen */
+   cleardevice();  /* clear screen */
+   restore_screen(ptr);  /* restore the screen */
+   getch();  /* pause screen */
+   closegraph();
+   return 0;
+}
+void save_screen(void *buf[4])
+{
+   unsigned size;
+   int ystart=0, yend, yincr, block;
+   yincr = (maxy+1) / 4;
+   yend = yincr;
+   /* get byte size of image */
+   size = imagesize(0, ystart, maxx, yend);
+   for (block=0; block<=3; block++) {
+if ((buf[block] = farmalloc(size)) == NULL) {
+   closegraph();
+   printf("Error: not enough heap space in save_screen().\n");
+   exit(1);
+}
+     getimage(0, ystart, maxx, yend, buf[block]);
+     ystart = yend + 1;
+     yend += yincr + 1;
+   }
+}
+void restore_screen(void *buf[4])
+{
+   int ystart=0, yend, yincr, block;
+   yincr = (maxy+1) / 4;
+   yend = yincr;
+   for (block=0; block<=3; block++) {
+putimage(0, ystart, buf[block], COPY_PUT);
+farfree(buf[block]);
+ystart = yend + 1;
+yend += yincr + 1;
+   }
+}
+</code>
+==== See also ====
+[[getpixel]]
+[[imagesize]]
+[[putimage]]
+===== output of getimage example =====
+    no output of example at the moment
+    do not hesitate and add it...

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