From 3c9ae99ddad51a5d7acf5867973fc30cef9593c1 Mon Sep 17 00:00:00 2001
From: Romain Vimont <rom@rom1v.com>
Date: Fri, 17 Apr 2020 18:43:29 +0200
Subject: [PATCH] Move rotation coordinates to screen

Move the window-to-frame coordinates conversion from the input manager
to the screen.

This will allow to apply more screen-related transformations without
impacting the input manager.
---
 app/src/input_manager.c | 37 ++++---------------------------------
 app/src/screen.c        | 30 ++++++++++++++++++++++++++++++
 app/src/screen.h        |  5 +++++
 3 files changed, 39 insertions(+), 33 deletions(-)

diff --git a/app/src/input_manager.c b/app/src/input_manager.c
index 72f15ee3..14ee7e40 100644
--- a/app/src/input_manager.c
+++ b/app/src/input_manager.c
@@ -442,36 +442,6 @@ input_manager_process_key(struct input_manager *im,
     }
 }
 
-static struct point
-rotate_position(struct screen *screen, int32_t x, int32_t y) {
-    unsigned rotation = screen->rotation;
-    assert(rotation < 4);
-
-    int32_t w = screen->content_size.width;
-    int32_t h = screen->content_size.height;
-    struct point result;
-    switch (rotation) {
-        case 0:
-            result.x = x;
-            result.y = y;
-            break;
-        case 1:
-            result.x = h - y;
-            result.y = x;
-            break;
-        case 2:
-            result.x = w - x;
-            result.y = h - y;
-            break;
-        default:
-            assert(rotation == 3);
-            result.x = y;
-            result.y = w - x;
-            break;
-    }
-    return result;
-}
-
 static bool
 convert_mouse_motion(const SDL_MouseMotionEvent *from, struct screen *screen,
                      struct control_msg *to) {
@@ -480,7 +450,7 @@ convert_mouse_motion(const SDL_MouseMotionEvent *from, struct screen *screen,
     to->inject_touch_event.pointer_id = POINTER_ID_MOUSE;
     to->inject_touch_event.position.screen_size = screen->frame_size;
     to->inject_touch_event.position.point =
-        rotate_position(screen, from->x, from->y);
+        screen_convert_to_frame_coords(screen, from->x, from->y);
     to->inject_touch_event.pressure = 1.f;
     to->inject_touch_event.buttons = convert_mouse_buttons(from->state);
 
@@ -520,7 +490,8 @@ convert_touch(const SDL_TouchFingerEvent *from, struct screen *screen,
     // SDL touch event coordinates are normalized in the range [0; 1]
     float x = from->x * screen->content_size.width;
     float y = from->y * screen->content_size.height;
-    to->inject_touch_event.position.point = rotate_position(screen, x, y);
+    to->inject_touch_event.position.point =
+        screen_convert_to_frame_coords(screen, x, y);
     to->inject_touch_event.pressure = from->pressure;
     to->inject_touch_event.buttons = 0;
     return true;
@@ -556,7 +527,7 @@ convert_mouse_button(const SDL_MouseButtonEvent *from, struct screen *screen,
     to->inject_touch_event.pointer_id = POINTER_ID_MOUSE;
     to->inject_touch_event.position.screen_size = screen->frame_size;
     to->inject_touch_event.position.point =
-        rotate_position(screen, from->x, from->y);
+        screen_convert_to_frame_coords(screen, from->x, from->y);
     to->inject_touch_event.pressure = 1.f;
     to->inject_touch_event.buttons =
         convert_mouse_buttons(SDL_BUTTON(from->button));
diff --git a/app/src/screen.c b/app/src/screen.c
index ea1b13f2..d4f96a39 100644
--- a/app/src/screen.c
+++ b/app/src/screen.c
@@ -553,3 +553,33 @@ screen_handle_window_event(struct screen *screen,
             break;
     }
 }
+
+struct point
+screen_convert_to_frame_coords(struct screen *screen, int32_t x, int32_t y) {
+    unsigned rotation = screen->rotation;
+    assert(rotation < 4);
+
+    int32_t w = screen->content_size.width;
+    int32_t h = screen->content_size.height;
+    struct point result;
+    switch (rotation) {
+        case 0:
+            result.x = x;
+            result.y = y;
+            break;
+        case 1:
+            result.x = h - y;
+            result.y = x;
+            break;
+        case 2:
+            result.x = w - x;
+            result.y = h - y;
+            break;
+        default:
+            assert(rotation == 3);
+            result.x = y;
+            result.y = w - x;
+            break;
+    }
+    return result;
+}
diff --git a/app/src/screen.h b/app/src/screen.h
index c9e019a1..85514279 100644
--- a/app/src/screen.h
+++ b/app/src/screen.h
@@ -114,4 +114,9 @@ screen_set_rotation(struct screen *screen, unsigned rotation);
 void
 screen_handle_window_event(struct screen *screen, const SDL_WindowEvent *event);
 
+// convert point from window coordinates to frame coordinates
+// x and y are expressed in pixels
+struct point
+screen_convert_to_frame_coords(struct screen *screen, int32_t x, int32_t y);
+
 #endif