fix coordinates of long press (right click)

kambala-decapitator/vcmi#1 kambala-decapitator/vcmi#26

client/SDL_uikit_main.m

@@ -3,12 +3,15 @@
 */
 
 /* Include the SDL main definition header */
-#include "SDL_main.h"
+#include <SDL_main.h>
 
-#include "SDL_events.h"
+#include <SDL_events.h>
+#include <SDL_render.h>
 
 @import UIKit;
 
+extern SDL_Window * mainWindow;
+
 
 @interface SDLViewObserver : NSObject
 @end
@@ -18,6 +21,7 @@
 - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context {
     __auto_type longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)];
     longPress.minimumPressDuration = 0.1;
+    longPress.delaysTouchesBegan = YES; // prevent normal clicks by SDL
     [(UIView *)[object valueForKey:keyPath] addGestureRecognizer:longPress];
 }
 
@@ -35,16 +39,38 @@
             return;
     }
 
+    __auto_type renderer = SDL_GetRenderer(mainWindow);
+    float scaleX, scaleY;
+    SDL_Rect viewport;
+    SDL_RenderGetScale(renderer, &scaleX, &scaleY);
+    SDL_RenderGetViewport(renderer, &viewport);
+
     __auto_type touchedPoint = [gesture locationInView:gesture.view];
-    SDL_Event event;
-    event.button = (SDL_MouseButtonEvent){
+    __auto_type screenScale = UIScreen.mainScreen.nativeScale;
+    Sint32 x = (int)touchedPoint.x * screenScale / scaleX - viewport.x;
+    Sint32 y = (int)touchedPoint.y * screenScale / scaleY - viewport.y;
+
+    SDL_Event rmbEvent;
+    rmbEvent.button = (SDL_MouseButtonEvent){
         .type = mouseButtonType,
         .button = SDL_BUTTON_RIGHT,
         .clicks = 1,
-        .x = touchedPoint.x,
-        .y = touchedPoint.y,
+        .x = x,
+        .y = y,
     };
-    SDL_PushEvent(&event);
+    SDL_PushEvent(&rmbEvent);
+
+    // small hack to prevent cursor jumping
+    if (mouseButtonType == SDL_MOUSEBUTTONUP)
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.025 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
+            SDL_Event motionEvent;
+            motionEvent.motion = (SDL_MouseMotionEvent){
+                .type = SDL_MOUSEMOTION,
+                .x = x,
+                .y = y,
+            };
+            SDL_PushEvent(&motionEvent);
+        });
 }
 
 @end