overlapping images: fix background and clipping borders (~mintty#1010)

JNylson · Jun 9, 2020 · 2b941d6 · 2b941d6
1 parent baa45da
commit 2b941d6
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Showing 2 changed files with 25 additions and 5 deletions.
diff --git a/src/winimg.c b/src/winimg.c
@@ -231,6 +231,7 @@ strage_read(temp_strage_t *strage, unsigned char *p, size_t size)
 
 
 #define dont_debug_img_list
+#define dont_debug_img_disp
 
 static uint
 winimg_len(imglist *img)
@@ -253,7 +254,9 @@ winimg_new(imglist **ppimg, char * id, unsigned char * pixels, uint len,
 #endif
 
   static int _imgi = 0;
-  //printf("winimg_new %d @%d\n", _imgi, top);
+#ifdef debug_img_disp
+  printf("winimg_new %d @%d:%d\n", _imgi, left, top);
+#endif
   img->imgi = _imgi++;
 
   img->pixels = pixels;
@@ -645,11 +648,14 @@ winimgs_paint(void)
 
   HDC dc = GetDC(wnd);
 
+#ifdef pre_clip
+  // this does not appear to be necessary
   RECT rc;
   GetClientRect(wnd, &rc);
   IntersectClipRect(dc, rc.left + PADDING, rc.top + PADDING,
                     rc.left + PADDING + term.cols * cell_width,
                     rc.top + PADDING + term.rows * cell_height);
+#endif
 
   imglist * prev = 0;
   for (img = term.imgs.first; img;) {
@@ -675,7 +681,7 @@ winimgs_paint(void)
 #ifdef debug_img_list
         printf("paint: check img %p v@%d s@%d\n", img, img->top, top);
 #endif
-        // create DC handle if it is not initialized, or resume from hibernate
+        // create img DC handle if not initialized, or resume from hibernate
         winimg_lazyinit(img);
 
         // check all cells of image area;
@@ -693,9 +699,13 @@ winimgs_paint(void)
             bool clip_flag = false;
             if (dchar->chr != SIXELCH)
               clip_flag = true;
-            else if (img->imgi - dchar->attr.imgi >= 0)
+            else if (img->imgi - dchar->attr.imgi >= 0) {
               // need to keep newer image, as sync may take a while
+#ifdef debug_img_disp
+            printf("paint: dirty (%d) %d:%d %d >= %d\n", disp_flag, y, x, img->imgi, dchar->attr.imgi);
+#endif
               disp_flag = true;
+            }
             // if cell is overlaid by selection or cursor, exclude
             if (dchar->attr.attr & (TATTR_RESULT | TATTR_CURRESULT | TATTR_MARKED | TATTR_CURMARKED))
               clip_flag = true;
@@ -724,7 +734,10 @@ winimgs_paint(void)
           // better background handling implemented below; this version 
           // would expose artefacts if a transparent image is scrolled
         }
-        else {
+        else if (disp_flag) {
+#ifdef debug_img_disp
+          printf("paint: clear background\n");
+#endif
           // determine image size for padding
           int iwidth;
           int iheight;
@@ -786,12 +799,16 @@ winimgs_paint(void)
             DeleteObject(hbm);
             DeleteDC(hdc);
           }
-          else
+          else {
             StretchBlt(dc,
                        left * cell_width + PADDING, top * cell_height + PADDING,
                        img->width * cell_width, img->height * cell_height,
                        img->hdc,
                        0, 0, img->pixelwidth, img->pixelheight, SRCCOPY);
+          }
+          // restore clipping region
+          ReleaseDC(wnd, dc);
+          dc = GetDC(wnd);
         }
         else if (top < 0 || top + img->height > term.rows) {
           // we did not check the scrolled-out image part, 

diff --git a/wiki/Changelog.md b/wiki/Changelog.md
@@ -1,3 +1,6 @@
+Window handling
+  * For overlapping images, fixed background and clipping borders (~#1010).
+
 ### 3.1.8 (7 June 2020) ###
 
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