More fallout from non-square pixels...

This fixes all the window adjustment "stuff", but the new aspect
ratio enforcement means that ALT-UP and ALT-DOWN are useless for
resizing the window unless it's not already snapped... use ALT-LEFT
and ALT-RIGHT to decrease/increase the window size.

src/conio/sdl_con.c

@@ -797,29 +797,13 @@ static int win_to_res_ypos(int winpos)
 void sdl_video_event_thread(void *data)
 {
 	SDL_Event	ev;
-	int		old_w, old_h;
 	int		block_text = 0;
 	static SDL_Keycode last_sym = SDLK_UNKNOWN;
 	static Uint16 last_mod = 0;
 
-	pthread_mutex_lock(&vstatlock);
-	old_w = cvstat.winwidth;
-	old_h = cvstat.winheight;
-	pthread_mutex_unlock(&vstatlock);
-
 	while(1) {
-		if(sdl.WaitEventTimeout(&ev, 1)!=1) {
-			pthread_mutex_lock(&vstatlock);
-			if (cvstat.winwidth != old_w || cvstat.winheight != old_h) {
-				sdl_setwinsize_locked(cvstat.winwidth, cvstat.winheight);
-				setup_surfaces_locked();
-				old_w = cvstat.winwidth;
-				old_h = cvstat.winheight;
-				sdl_getwinsize_locked(&cvstat.winwidth, &cvstat.winheight);
-			}
-			pthread_mutex_unlock(&vstatlock);
-		}
-		else {
+		if(sdl.WaitEventTimeout(&ev, 1)!=1)
+			continue;
 		switch (ev.type) {
 			case SDL_KEYDOWN:			/* Keypress */
 				last_mod = ev.key.keysym.mod;
@@ -863,15 +847,6 @@ void sdl_video_event_thread(void *data)
 									}
 									break;
 								case SDLK_DOWN:
-										if (cvstat.scale_denominator != cvstat.scale_numerator) {
-											if (h % (cvstat.scrnheight * cvstat.vmultiplier) == 0) {
-												h = h * cvstat.scale_denominator / cvstat.scale_numerator;
-											}
-											else {
-												h = (h - h % (cvstat.scrnheight * cvstat.vmultiplier)) + (cvstat.scrnheight * cvstat.vmultiplier);
-											}
-										}
-										else
 									h = (h - h % (cvstat.scrnheight * cvstat.vmultiplier)) + (cvstat.scrnheight * cvstat.vmultiplier);
 									break;
 							}
@@ -881,6 +856,7 @@ void sdl_video_event_thread(void *data)
 								cvstat.winwidth = w;
 								cvstat.winheight = h;
 							}
+							setup_surfaces_locked();
 							pthread_mutex_unlock(&vstatlock);
 						}
 						break;
@@ -998,7 +974,6 @@ void sdl_video_event_thread(void *data)
 							else
 								newh = "0";
 							pthread_mutex_lock(&win_mutex);
-								if (ev.window.event == SDL_WINDOWEVENT_RESIZED)
 							sdl.GetWindowSize(win, &cvstat.winwidth, &cvstat.winheight);
 							if (strcmp(newh, sdl.GetHint(SDL_HINT_RENDER_SCALE_QUALITY))) {
 								SDL_Texture *newtexture;
@@ -1008,8 +983,9 @@ void sdl_video_event_thread(void *data)
 								if (texture)
 									sdl.DestroyTexture(texture);
 								texture = newtexture;
-									bitmap_drv_request_pixels();
 							}
+							sdl.RenderClear(renderer);
+							bitmap_drv_request_pixels();
 							pthread_mutex_unlock(&win_mutex);
 							pthread_mutex_unlock(&vstatlock);
 							break;
@@ -1080,11 +1056,11 @@ void sdl_video_event_thread(void *data)
 									idealw = roundl((long double)dst.h * cvstat.scale_numerator / cvstat.scale_denominator * cvstat.scrnwidth / cvstat.scrnheight);
 									idealh = roundl((long double)dst.w * cvstat.scale_denominator / cvstat.scale_numerator * cvstat.scrnheight / cvstat.scrnwidth);
 									if (idealw < cvstat.winwidth) {
-											dst.x += (cvstat.winwidth - idealw) / 2;
+										dst.x = (cvstat.winwidth - idealw) / 2;
 										dst.w = idealw;
 									}
 									else if(idealh < cvstat.winheight) {
-											dst.y += (cvstat.winheight - idealh) / 2;
+										dst.y = (cvstat.winheight - idealh) / 2;
 										dst.h = idealh;
 									}
 									sdl.RenderCopy(renderer, texture, &src, &dst);
@@ -1128,8 +1104,6 @@ void sdl_video_event_thread(void *data)
 					case SDL_USEREVENT_SETVIDMODE:
 						pthread_mutex_lock(&vstatlock);
 						setup_surfaces_locked();
-							old_w = cvstat.winwidth;
-							old_h = cvstat.winheight;
 						pthread_mutex_unlock(&vstatlock);
 						sdl_ufunc_retval=0;
 						sem_post(&sdl_ufunc_ret);
@@ -1197,7 +1171,6 @@ void sdl_video_event_thread(void *data)
 				break;
 		}
 	}
-	}
 	return;
 }