1 files changed, 97 insertions, 0 deletions
diff --git a/WebInterface/wasm/asm-paint/src/shader.rs b/WebInterface/wasm/asm-paint/src/shader.rs
new file mode 100644
index 0000000..3352bcf
--- /dev/null
+++ b/WebInterface/wasm/asm-paint/src/shader.rs
@@ -0,0 +1,97 @@
+use web_sys::{WebGlProgram, WebGl2RenderingContext};
+
+const VERTEX_SHADER: &str =
+r#"#version 300 es
+in vec4 pos;
+void main() {
+    gl_Position = pos;
+}
+"#;
+
+const FRAGMENT_SHADER: &str =
+r#"#version 300 es
+precision mediump float;
+out vec4 color;
+
+void main() {
+    color = vec4(1, 0, 0, 1);
+}
+"#;
+
+pub struct Shaders {
+    program: Option<WebGlProgram>,
+    pos_loc: i32,
+}
+
+impl Shaders {
+    pub fn new() -> Self {
+        Self {
+            program: None,
+            pos_loc: -1
+        }
+    }
+
+    fn create_program(&mut self, ctx: &WebGl2RenderingContext) -> Result<(), String> {
+        self.program = Some(ctx.create_program().ok_or("could not create program id")?);
+        Ok(())
+    }
+
+    fn create_shader(&mut self, ctx: &WebGl2RenderingContext,
+                     shader_type: u32, source: &str) -> Result<(), String> {
+        let program = self.program.as_ref().ok_or("could not find created program")?;
+        let shader = ctx.create_shader(shader_type)
+            .ok_or("could not create shader")?;
+        ctx.shader_source(&shader, source);
+        ctx.compile_shader(&shader);
+        let status = ctx.get_shader_parameter(&shader, WebGl2RenderingContext::COMPILE_STATUS);
+        if status == wasm_bindgen::JsValue::TRUE {
+            ctx.attach_shader(program, &shader);
+            Ok(())
+        } else {
+            Err(format!("\n{}", ctx.get_shader_info_log(&shader).unwrap_or_default()))
+        }
+    }
+
+    fn create_vertex_shader(&mut self, ctx: &WebGl2RenderingContext) -> Result<(), String> {
+        self.create_shader(ctx, WebGl2RenderingContext::VERTEX_SHADER, VERTEX_SHADER)
+    }
+
+    fn create_fragment_shader(&mut self, ctx: &WebGl2RenderingContext) -> Result<(), String> {
+        self.create_shader(ctx, WebGl2RenderingContext::FRAGMENT_SHADER, FRAGMENT_SHADER)
+    }
+
+    fn compile(&mut self, ctx: &WebGl2RenderingContext) -> Result<(), String> {
+        let program = self.program.as_ref().ok_or("could not find created program")?;
+        ctx.link_program(program);
+        let status = ctx.get_program_parameter(program, WebGl2RenderingContext::LINK_STATUS);
+        if status == wasm_bindgen::JsValue::TRUE {
+            Ok(())
+        } else {
+            Err(format!("\n{}", ctx.get_program_info_log(program).unwrap_or_default()))
+        }
+    }
+
+    pub fn init(&mut self, ctx: &WebGl2RenderingContext) -> Result<(), String> {
+        debug!("create program");
+        self.create_program(ctx)
+            .map_err(|e| { error!("webgl2 create program: {}", e); e})?;
+        debug!("create vertex shader");
+        self.create_vertex_shader(ctx)
+            .map_err(|e| { error!("webgl2 create vertex shader: {}", e); e})?;
+        debug!("create fragment shader");
+        self.create_fragment_shader(ctx)
+            .map_err(|e| { error!("webgl2 create fragment shader: {}", e); e})?;
+        debug!("compile shader program");
+        self.compile(ctx)
+            .map_err(|e| { error!("webgl2 shader: {}", e); e})?;
+        let program = self.program.as_ref().ok_or("could not find created program")?;
+        self.pos_loc = ctx.get_attrib_location(program, "pos");
+        trace!("got attrib location 'pos'({})", self.pos_loc);
+        info!("initialised shader program");
+        Ok(())
+    }
+
+    pub fn remove(&mut self, ctx: &WebGl2RenderingContext) {
+        ctx.delete_program(self.program.as_ref())
+    }
+}