draw triangle

2023-04-28 20:01:48 -07:00
parent 3e7bf2dd80
commit d7c2d5adb9
7 changed files with 261 additions and 1 deletions
--- a/graphics.ts
+++ b/graphics.ts
@@ -0,0 +1,93 @@
+import {
+	DwmWindow,
+	gl
+} from "./deps.ts";
+
+function loadShader(type: number, src: string) {
+	const shader = gl.CreateShader(type);
+	gl.ShaderSource(
+		shader,
+		1,
+		new Uint8Array(
+			new BigUint64Array([
+				BigInt(
+					Deno.UnsafePointer.value(
+						Deno.UnsafePointer.of(new TextEncoder().encode(src)),
+					),
+				),
+			]).buffer,
+		),
+		new Int32Array([src.length]),
+	);
+	gl.CompileShader(shader);
+	const status = new Int32Array(1);
+	gl.GetShaderiv(shader, gl.COMPILE_STATUS, status);
+	if (status[0] === gl.FALSE) {
+		const logLength = new Int32Array(1);
+		gl.GetShaderiv(shader, gl.INFO_LOG_LENGTH, logLength);
+		const log = new Uint8Array(logLength[0]);
+		gl.GetShaderInfoLog(shader, logLength[0], logLength, log);
+		console.log(new TextDecoder().decode(log));
+		gl.DeleteShader(shader);
+		return 0;
+	}
+	return shader;
+}
+
+const vShaderSrc = `
+  attribute vec4 vPosition;
+  void main() {
+	gl_Position = vPosition;
+  }
+  `;
+
+const fShaderSrc = `
+  void main() {
+	gl_FragColor = vec4(1.0, 1.0, 0.0, 1.0);
+  }
+  `;
+
+const vShader = loadShader(gl.VERTEX_SHADER, vShaderSrc);
+const fShader = loadShader(gl.FRAGMENT_SHADER, fShaderSrc);
+
+const program = gl.CreateProgram();
+gl.AttachShader(program, vShader);
+gl.AttachShader(program, fShader);
+
+gl.BindAttribLocation(program, 0, new TextEncoder().encode("vPosition\0"));
+
+gl.LinkProgram(program);
+
+const status = new Int32Array(1);
+gl.GetProgramiv(program, gl.LINK_STATUS, status);
+if (status[0] === gl.FALSE) {
+	const logLength = new Int32Array(1);
+	gl.GetProgramiv(program, gl.INFO_LOG_LENGTH, logLength);
+	const log = new Uint8Array(logLength[0]);
+	gl.GetProgramInfoLog(program, logLength[0], logLength, log);
+	console.log(new TextDecoder().decode(log));
+	gl.DeleteProgram(program);
+	Deno.exit(1);
+}
+
+gl.ClearColor(0.0, 0.0, 0.0, 1.0);
+
+addEventListener("resize", (event) => {
+	gl.Viewport(0, 0, event.width, event.height);
+});
+
+export const makeFrameFunc = (swapBuffers: DwmWindow["swapBuffers"]) => {
+	return () => {
+		gl.Clear(gl.COLOR_BUFFER_BIT);
+		gl.UseProgram(program);
+		// deno-fmt-ignore
+		gl.VertexAttribPointer(0, 3, gl.FLOAT, gl.FALSE, 0, new Float32Array([
+			0.0, 0.5, 0.0,  
+			-0.5, 0.0, 0.0,
+			0.5, 0.0, 0.0,
+		]));
+		gl.EnableVertexAttribArray(0);
+		gl.DrawArrays(gl.TRIANGLES, 0, 3);
+		swapBuffers();
+	}
+}