Fix desktop launch, app icons and keyboard parameter editing

vendor/egui-wgpu/src/texture_copy.wgsl

@@ -0,0 +1,43 @@
+struct VertexOutput {
+    @builtin(position) position: vec4<f32>,
+};
+
+var<private> positions: array<vec2f, 3> = array<vec2f, 3>(
+    vec2f(-1.0, -3.0),
+    vec2f(-1.0, 1.0),
+    vec2f(3.0, 1.0)
+);
+
+// meant to be called with 3 vertex indices: 0, 1, 2
+// draws one large triangle over the clip space like this:
+// (the asterisks represent the clip space bounds)
+//-1,1           1,1
+// ---------------------------------
+// |              *              .
+// |              *           .
+// |              *        .
+// |              *      .
+// |              *    .
+// |              * .
+// |***************
+// |            . 1,-1
+// |          .
+// |       .
+// |     .
+// |   .
+// |.
+@vertex
+fn vs_main(@builtin(vertex_index) vertex_index: u32) -> VertexOutput {
+    var result: VertexOutput;
+    result.position = vec4f(positions[vertex_index], 0.0, 1.0);
+    return result;
+}
+
+@group(0)
+@binding(0)
+var r_color: texture_2d<f32>;
+
+@fragment
+fn fs_main(vertex: VertexOutput) -> @location(0) vec4<f32> {
+    return textureLoad(r_color, vec2i(vertex.position.xy), 0);
+}