Add rendering loop

1 files changed, 20 insertions, 9 deletions

diff --git a/webhogg/wasm/src/context/graphics.rs b/webhogg/wasm/src/context/graphics.rs
index 853e1e1..b94441d 100644
--- a/webhogg/wasm/src/context/graphics.rs
+++ b/webhogg/wasm/src/context/graphics.rs
@@ -4,16 +4,12 @@ use wasm_bindgen::JsCast;
 use web_sys::WebGl2RenderingContext as Gl;
 
 pub struct GraphicsContext {
+    gl: Gl,
+    frame_nr: u64,
 }
 
 impl GraphicsContext {
     pub fn from_canvas(canvas: web_sys::OffscreenCanvas) -> Result<Self, WasmError> {
-        /*debug!("canvas object usw.: {:?}", canvas);
-        let canvas: web_sys::OffscreenCanvas = js_sys::Reflect::get(&canvas,
-                                          &wasm_bindgen::JsValue::from_str("canvas"))
-            .map_err(|_| WasmError::WebGl2ContextCreation(
-                    format!("canvas object is not defined")))?
-            .into();*/
         let context = canvas.get_context("webgl2")
             .map_err(|_| WasmError::WebGl2ContextCreation(
                     format!("context cration failed: getContext returned an exception")))?
@@ -23,11 +19,26 @@ impl GraphicsContext {
             .dyn_into::<Gl>()
             .map_err(|_| WasmError::WebGl2ContextCreation(
                     format!("context object is not a context")))?;
-
-        context.clear_color(0.6, 0.0, 0.6, 1.0);
-        context.clear(Gl::COLOR_BUFFER_BIT);
             
         Ok(Self {
+            gl: context,
+            frame_nr: 0,
         })
     }
+
+    pub fn update(&mut self) -> Result<(), WasmError> {
+        let light = 0.5;
+
+        let a = (self.frame_nr as f32) / 60.0;
+        let a = f32::abs(f32::sin(a));
+        let b = f32::abs(f32::cos(a));
+        let (a, b) = (a * light, b * light);
+
+        self.gl.clear_color(a, light - a, b, 1.0);
+        self.gl.clear(Gl::COLOR_BUFFER_BIT);
+
+        self.frame_nr += 1;
+
+        Ok(())
+    }
 }