+
+/* copy the entire screen to the window at the scroll position */
+
+void BlitScreenToBitmap_SP(Bitmap *target_bitmap)
+{
+ int sx = TILEX + mScrollX % TILEX;
+ int sy = TILEY + mScrollY % TILEY;
+
+ BlitBitmap(screenBitmap, target_bitmap, sx, sy,
+ SCR_FIELDX * TILEX, SCR_FIELDY * TILEY, SX, SY);
+}
+
+void OLD_BlitScreenToBitmap_SP(Bitmap *target_bitmap)
+{
+ int x = mScrollX % (MAX_BUF_XSIZE * TILEX);
+ int y = mScrollY % (MAX_BUF_YSIZE * TILEY);
+
+ if (x < 2 * TILEX && y < 2 * TILEY)
+ {
+ BlitBitmap(screenBitmap, target_bitmap, x, y,
+ SCR_FIELDX * TILEX, SCR_FIELDY * TILEY, SX, SY);
+ }
+ else if (x < 2 * TILEX && y >= 2 * TILEY)
+ {
+ BlitBitmap(screenBitmap, target_bitmap, x, y,
+ SCR_FIELDX * TILEX, MAX_BUF_YSIZE * TILEY - y,
+ SX, SY);
+ BlitBitmap(screenBitmap, target_bitmap, x, 0,
+ SCR_FIELDX * TILEX, y - 2 * TILEY,
+ SX, SY + MAX_BUF_YSIZE * TILEY - y);
+ }
+ else if (x >= 2 * TILEX && y < 2 * TILEY)
+ {
+ BlitBitmap(screenBitmap, target_bitmap, x, y,
+ MAX_BUF_XSIZE * TILEX - x, SCR_FIELDY * TILEY,
+ SX, SY);
+ BlitBitmap(screenBitmap, target_bitmap, 0, y,
+ x - 2 * TILEX, SCR_FIELDY * TILEY,
+ SX + MAX_BUF_XSIZE * TILEX - x, SY);
+ }
+ else
+ {
+ BlitBitmap(screenBitmap, target_bitmap, x, y,
+ MAX_BUF_XSIZE * TILEX - x, MAX_BUF_YSIZE * TILEY - y,
+ SX, SY);
+ BlitBitmap(screenBitmap, target_bitmap, 0, y,
+ x - 2 * TILEX, MAX_BUF_YSIZE * TILEY - y,
+ SX + MAX_BUF_XSIZE * TILEX - x, SY);
+ BlitBitmap(screenBitmap, target_bitmap, x, 0,
+ MAX_BUF_XSIZE * TILEX - x, y - 2 * TILEY,
+ SX, SY + MAX_BUF_YSIZE * TILEY - y);
+ BlitBitmap(screenBitmap, target_bitmap, 0, 0,
+ x - 2 * TILEX, y - 2 * TILEY,
+ SX + MAX_BUF_XSIZE * TILEX - x, SY + MAX_BUF_YSIZE * TILEY - y);
+ }
+}
+
+void BackToFront_SP(void)
+{
+ static boolean scrolling_last = FALSE;
+ int left = mScrollX / TILEX;
+ int top = mScrollY / TILEY;
+ boolean scrolling = (mScrollX % TILEX != 0 || mScrollY % TILEY != 0);
+ int x, y;
+
+ SyncDisplay();
+
+ if (1 ||
+ redraw_tiles > REDRAWTILES_THRESHOLD || scrolling || scrolling_last)
+ {
+ /* blit all (up to four) parts of the scroll buffer to the backbuffer */
+ BlitScreenToBitmap_SP(backbuffer);
+
+ /* blit the completely updated backbuffer to the window (in one blit) */
+ BlitBitmap(backbuffer, window, SX, SY, SXSIZE, SYSIZE, SX, SY);
+ }
+ else
+ {
+ for (x = 0; x < SCR_FIELDX; x++)
+ {
+ for (y = 0; y < SCR_FIELDY; y++)
+ {
+ int xx = (left + x) % MAX_BUF_XSIZE;
+ int yy = (top + y) % MAX_BUF_YSIZE;
+
+ if (redraw[xx][yy])
+ BlitBitmap(screenBitmap, window,
+ xx * TILEX, yy * TILEY, TILEX, TILEY,
+ SX + x * TILEX, SY + y * TILEY);
+ }
+ }
+ }
+
+ FlushDisplay();
+
+ for (x = 0; x < MAX_BUF_XSIZE; x++)
+ for (y = 0; y < MAX_BUF_YSIZE; y++)
+ redraw[x][y] = FALSE;
+ redraw_tiles = 0;
+
+ scrolling_last = scrolling;
+}
+
+
+void DDScrollBuffer_Blt_Ext(Bitmap *target_bitmap)