From 380416fa2dce64b8c32e9dfb2614ded99a99ebf2 Mon Sep 17 00:00:00 2001
From: Peter <craven@gmx.net>
Date: Fri, 22 Oct 2021 07:34:03 +0200
Subject: [PATCH] Only update texture on damage.

---
 src/initdsp.c | 12 ++++++++----
 src/sdl.c     | 30 ++++++++++++++++--------------
 2 files changed, 24 insertions(+), 18 deletions(-)

diff --git a/src/initdsp.c b/src/initdsp.c
index a98f771..285450e 100644
--- a/src/initdsp.c
+++ b/src/initdsp.c
@@ -80,6 +80,10 @@ extern DLword *ColorDisplayRegion68k;
 extern int MonoOrColor;
 #endif /* COLOR */
 
+#ifdef SDL
+extern void sdl_notify_damage(int, int, int, int);
+#endif /* SDL */
+
 #ifdef XWINDOW
 DLword *DisplayRegion68k_end_addr;
 extern int *Xdisplay; /* DAANGER -jarl nilsson 27-apr-92 */
@@ -264,7 +268,7 @@ in_display_segment(baseaddr)
 <<<<<<< HEAD
 void flush_display_buffer(void) {
 #ifdef SDL
-  //  sdl_bitblt_to_screen(0, 0, sdl_displaywidth, sdl_displayheight);
+  sdl_notify_damage(0, 0, sdl_displaywidth, sdl_displayheight);
 #endif
 #ifdef XWINDOW
   (currentdsp->bitblt_to_screen)(currentdsp, DisplayRegion68k, currentdsp->Visible.x,
@@ -295,7 +299,7 @@ void flush_display_region(int x, int y, int w, int h)
 {
   //  printf("flush_display_region %d %d %d %d\n", x, y, w, h);
 #ifdef SDL
-  //  sdl_bitblt_to_screen(x, y, w, h);
+  sdl_notify_damage(x, y, w, h);
 #endif
 #if (defined(XWINDOW) || defined(DOS))
   TPRINT(("Enter flush_display_region x=%d, y=%d, w=%d, h=%d\n", x, y, w, h));
@@ -341,7 +345,7 @@ void flush_display_lineregion(UNSIGNED x, DLword *ybase, int w, int h)
   y = ((DLword *)ybase - DisplayRegion68k) / DLWORD_PERLINE;
   //  printf("flush_display_lineregion %d %d %d %d\n", x, y, w, h);
 #ifdef SDL
-  //  sdl_bitblt_to_screen(x, y, w, h);
+  sdl_notify_damage(x, y, w, h);
 #endif
 #if (defined(XWINDOW) || defined(DOS))
   TPRINT(("Enter flush_display_lineregion x=%p, y=%d, w=%d, h=%d\n", (void *)x, y, w, h));
@@ -375,7 +379,7 @@ void flush_display_ptrregion(DLword *ybase, UNSIGNED bitoffset, int w, int h)
   x = bitoffset + (BITSPERWORD * (baseoffset - (DLWORD_PERLINE * y)));
   //  printf("flush_display_ptrregion %d %d %d %d\n", x, y, w, h);
 #ifdef SDL
-  //  sdl_bitblt_to_screen(x, y, w, h);
+  sdl_notify_damage(x, y, w, h);
 #endif
 #if   (defined(XWINDOW) || defined(DOS))
   TPRINT(("Enter flush_display_ptrregion\n x=%d, y=%d, w=%d, h=%d\n", x, y, w, h));
diff --git a/src/sdl.c b/src/sdl.c
index 6ef8103..b321080 100644
--- a/src/sdl.c
+++ b/src/sdl.c
@@ -207,8 +207,12 @@ void set_pixel(SDL_Surface *surface, int x, int y, Uint32 pixel)
 }
 int should_update_texture = 0;
 
+void sdl_notify_damage(int x, int y, int w, int h) {
+  should_update_texture = 1;
+}
+
 void sdl_bitblt_to_screen(int _x, int _y, int _w, int _h) {
-  //  printf("bitblting\n");
+  //printf("bitblting\n");
   int before = SDL_GetTicks();
   int width = sdl_displaywidth;
   int height = sdl_displayheight;
@@ -234,7 +238,7 @@ void sdl_bitblt_to_screen(int _x, int _y, int _w, int _h) {
       }
     }
   }
-  should_update_texture = 1;
+  //should_update_texture = 1;
   int after = SDL_GetTicks();
   //  printf("bitblting took %dms\n", after - before);
   /* before = SDL_GetTicks(); */
@@ -414,27 +418,25 @@ void process_SDLevents() {
     }
   }
   //  handle_keyboard();
-  /* sdl_bitblt_to_screen(); */
-  // SDL_UpdateTexture(sdl_texture, NULL, buffer, sdl_displaywidth * sizeof(Uint32));
   int before = 0;
   int after = 0;
-  /* if(should_update_texture) { */
-  /*   before = SDL_GetTicks(); */
-  /*   SDL_UpdateTexture(sdl_texture, NULL, buffer, sdl_displaywidth * sizeof(Uint32)); */
-  /*   after = SDL_GetTicks(); */
-  /*   should_update_texture = 0; */
-  /* } */
-  //  printf("UpdateTexture took %dms\n", after - before);
+  if(should_update_texture) {
+    before = SDL_GetTicks();
+    sdl_bitblt_to_screen(0, 0, sdl_displaywidth, sdl_displayheight);
+    SDL_UpdateTexture(sdl_texture, NULL, buffer, sdl_displaywidth * sizeof(Uint32));
+    after = SDL_GetTicks();
+    // printf("UpdateTexture took %dms\n", after - before);
+    should_update_texture = 0;
+  }
   int this_draw = SDL_GetTicks();
   before = SDL_GetTicks();
   //  printf("processing events took %dms\n", before - process_events_time);
   if(this_draw - last_draw > 16) {
     before = SDL_GetTicks();
-    SDL_UpdateTexture(sdl_texture, NULL, buffer, sdl_displaywidth * sizeof(Uint32));
+    /* SDL_UpdateTexture(sdl_texture, NULL, buffer, sdl_displaywidth * sizeof(Uint32)); */
     after = SDL_GetTicks();
-    should_update_texture = 0;
+    //    should_update_texture = 0;
 
-    sdl_bitblt_to_screen(0, 0, sdl_displaywidth, sdl_displayheight);
     SDL_RenderClear(sdl_renderer);
     SDL_Rect r;
     r.x = 0;