From 545f3af29e9a7762ecc712035d0f231d9a6e5285 Mon Sep 17 00:00:00 2001
From: Eduard-Mihai Burtescu <eddyb@lyken.rs>
Date: Sat, 15 Apr 2023 11:37:53 +0300
Subject: [PATCH] [WIP] mouse shader example on android w/ touch

---
 examples/runners/wgpu/src/graphics.rs | 40 +++++++++++++++++++++++++--
 examples/runners/wgpu/src/lib.rs      |  2 +-
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/examples/runners/wgpu/src/graphics.rs b/examples/runners/wgpu/src/graphics.rs
index 9a5bd43263..c857de5bc8 100644
--- a/examples/runners/wgpu/src/graphics.rs
+++ b/examples/runners/wgpu/src/graphics.rs
@@ -3,7 +3,10 @@ use crate::maybe_watch;
 use super::Options;
 use shared::ShaderConstants;
 use winit::{
-    event::{ElementState, Event, KeyboardInput, MouseButton, VirtualKeyCode, WindowEvent},
+    event::{
+        ElementState, Event, KeyboardInput, MouseButton, Touch, TouchPhase, VirtualKeyCode,
+        WindowEvent,
+    },
     event_loop::{ControlFlow, EventLoop, EventLoopBuilder},
     window::Window,
 };
@@ -297,7 +300,40 @@ async fn run(
                 }
             }
             Event::WindowEvent {
-                event: WindowEvent::CursorMoved { position, .. },
+                event:
+                    WindowEvent::Touch(Touch {
+                        phase: phase @ (TouchPhase::Started | TouchPhase::Ended | TouchPhase::Cancelled),
+                        ..
+                    }),
+                ..
+            } => {
+                // FIXME(eddyb) deduplicate!
+                let button = MouseButton::Left;
+                let mask = 1 << mouse_button_index(button);
+                match phase {
+                    TouchPhase::Started => {
+                        mouse_button_pressed |= mask;
+                        mouse_button_press_since_last_frame |= mask;
+
+                        if button == MouseButton::Left {
+                            drag_start_x = cursor_x;
+                            drag_start_y = cursor_y;
+                            drag_end_x = cursor_x;
+                            drag_end_y = cursor_y;
+                        }
+                    }
+                    TouchPhase::Moved => unreachable!(),
+                    TouchPhase::Ended | TouchPhase::Cancelled => mouse_button_pressed &= !mask,
+                }
+            }
+            Event::WindowEvent {
+                event:
+                    WindowEvent::CursorMoved { position, .. }
+                    | WindowEvent::Touch(Touch {
+                        phase: TouchPhase::Moved,
+                        location: position,
+                        ..
+                    }),
                 ..
             } => {
                 cursor_x = position.x as f32;
diff --git a/examples/runners/wgpu/src/lib.rs b/examples/runners/wgpu/src/lib.rs
index 4bdb7cd9cc..c19515d61b 100644
--- a/examples/runners/wgpu/src/lib.rs
+++ b/examples/runners/wgpu/src/lib.rs
@@ -153,7 +153,7 @@ fn maybe_watch(
 #[derive(StructOpt)]
 #[structopt(name = "example-runner-wgpu")]
 pub struct Options {
-    #[structopt(short, long, default_value = "Sky")]
+    #[structopt(short, long, default_value = "Mouse")]
     shader: RustGPUShader,
 }