4 files changed, 202 insertions, 0 deletions
diff --git a/src/renderer/runtime/view/renderer/renderer.ts b/src/renderer/runtime/view/renderer/renderer.ts
new file mode 100644
index 0000000..9f711d3
--- /dev/null
+++ b/src/renderer/runtime/view/renderer/renderer.ts
@@ -0,0 +1,100 @@
+import { nextPowerOf2 } from '../../util';
+import { Shaders } from './shaders';
+
+import { mat4, vec2 } from 'gl-matrix';
+
+export class Renderer {
+	public readonly coordScale = 32;
+	private readonly viewScale = 2;
+
+	private readonly gl: WebGLRenderingContext;
+	private readonly shaders: Shaders;
+
+	private readonly center: vec2 = vec2.create();
+	private readonly translation: vec2 = vec2.create();
+	private readonly viewport: mat4 = mat4.create();
+
+	constructor(private readonly canvas: HTMLCanvasElement) {
+		this.gl = this.mkContext();
+
+		this.shaders = new Shaders(this.gl);
+
+		this.gl.clearColor(0.0, 0.0, 0.0, 1.0);
+
+		this.gl.enable(this.gl.BLEND);
+		this.gl.blendFunc(this.gl.ONE, this.gl.ONE_MINUS_SRC_ALPHA);
+		this.gl.pixelStorei(this.gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, 1);
+	}
+
+	public createBuffer(): WebGLBuffer {
+		const ret = this.gl.createBuffer();
+		if (!ret)
+			throw new Error('unable to create buffer');
+
+		return ret;
+	}
+
+	public getContext(): WebGLRenderingContext {
+		return this.gl;
+	}
+
+	public getVertexPosLoc(): number {
+		return this.shaders.vertexPosLoc;
+	}
+
+	public getTextureCoordLoc(): number {
+		return this.shaders.textureCoordLoc;
+	}
+
+	public getSamplerLoc(): WebGLUniformLocation {
+		return this.shaders.samplerLoc;
+	}
+
+	public setCenter(v: vec2|number[]) {
+		this.snapToGrid(this.center, v);
+	}
+
+	public setTranslation(v: vec2|number[]) {
+		vec2.sub(this.translation, v, this.center);
+		this.snapToGrid(this.translation, this.translation);
+		this.gl.uniform2fv(this.shaders.translateLoc, this.translation);
+	}
+
+	public clear(): void {
+		this.gl.clear(this.gl.COLOR_BUFFER_BIT);
+
+		this.setTranslation([0, 0]);
+	}
+
+	public snapToGrid(out: vec2, a: vec2|number[]): void {
+		vec2.scale(out, a, this.coordScale);
+		vec2.round(out, out);
+		vec2.scale(out, out, 1 / this.coordScale);
+	}
+
+	public resize(): void {
+		const w = this.canvas.width;
+		const h = this.canvas.height;
+		const ws = nextPowerOf2(w);
+		const hs = nextPowerOf2(h);
+
+		this.gl.viewport((w - ws) / 2, (h - hs) / 2, ws, hs);
+		this.clear();
+
+		const scale = this.viewScale * this.coordScale;
+
+		mat4.identity(this.viewport);
+		mat4.scale(this.viewport, this.viewport, [2 * scale / ws, -2 * scale / hs, 1.0]);
+		this.gl.uniformMatrix4fv(this.shaders.viewportLoc, false, this.viewport);
+	}
+
+	private mkContext(): WebGLRenderingContext {
+		const gl = (
+			this.canvas.getContext('webgl') || this.canvas.getContext('experimental-webgl')
+		);
+		if (!gl)
+			throw new Error('unable to initialize WebGL context');
+
+		return gl;
+	}
+}
diff --git a/src/renderer/runtime/view/renderer/shaders.ts b/src/renderer/runtime/view/renderer/shaders.ts
new file mode 100644
index 0000000..8fd1fda
--- /dev/null
+++ b/src/renderer/runtime/view/renderer/shaders.ts
@@ -0,0 +1,79 @@
+import fragmentShaderSrc from './shaders/default.fs';
+import vertexShaderSrc from './shaders/default.vs';
+
+export class Shaders {
+	public readonly viewportLoc: WebGLUniformLocation;
+	public readonly translateLoc: WebGLUniformLocation;
+
+	public readonly vertexPosLoc: number;
+	public readonly textureCoordLoc: number;
+	public readonly samplerLoc: WebGLUniformLocation;
+
+	constructor(private readonly gl: WebGLRenderingContext) {
+		const shaderProgram = this.gl.createProgram();
+		if (!shaderProgram)
+			throw new Error('Unable to create shader program');
+
+		const vertexShader = this.compileShader(this.gl.VERTEX_SHADER, vertexShaderSrc);
+		const fragmentShader = this.compileShader(this.gl.FRAGMENT_SHADER, fragmentShaderSrc);
+
+		this.gl.attachShader(shaderProgram, vertexShader);
+		this.gl.attachShader(shaderProgram, fragmentShader);
+
+		this.gl.linkProgram(shaderProgram);
+		if (!this.gl.getProgramParameter(shaderProgram, this.gl.LINK_STATUS)) {
+			const err = this.gl.getProgramInfoLog(shaderProgram);
+
+			this.gl.deleteShader(vertexShader);
+			this.gl.deleteShader(fragmentShader);
+			this.gl.deleteProgram(shaderProgram);
+
+			throw new Error('Unable to link shader: ' + err);
+		}
+
+		this.gl.useProgram(shaderProgram);
+
+		this.vertexPosLoc = this.getAttribLocation(shaderProgram, 'aVertexPos');
+		this.gl.enableVertexAttribArray(this.vertexPosLoc);
+
+		this.textureCoordLoc = this.getAttribLocation(shaderProgram, 'aTextureCoord');
+		this.gl.enableVertexAttribArray(this.textureCoordLoc);
+
+		this.viewportLoc = this.getUniformLocation(shaderProgram, 'uViewport');
+		this.translateLoc = this.getUniformLocation(shaderProgram, 'uTranslate');
+		this.samplerLoc = this.getUniformLocation(shaderProgram, 'uSampler');
+	}
+
+	private compileShader(type: number, src: string): WebGLShader {
+		const shader = this.gl.createShader(type);
+		if (!shader)
+			throw new Error('Unable to create shader');
+
+		this.gl.shaderSource(shader, src);
+		this.gl.compileShader(shader);
+
+		if (!this.gl.getShaderParameter(shader, this.gl.COMPILE_STATUS)) {
+			const err = this.gl.getShaderInfoLog(shader);
+			this.gl.deleteShader(shader);
+			throw new Error('Unable to compile shader: ' + err);
+		}
+
+		return shader;
+	}
+
+	private getAttribLocation(program: WebGLProgram, name: string): number {
+		const ret = this.gl.getAttribLocation(program, name);
+		if (ret < 0)
+			throw new Error("unable to get location of attribute '" + name + "'");
+
+		return ret;
+	}
+
+	private getUniformLocation(program: WebGLProgram, name: string): WebGLUniformLocation {
+		const ret = this.gl.getUniformLocation(program, name);
+		if (!ret)
+			throw new Error("unable to get location of uniform '" + name + "'");
+
+		return ret;
+	}
+}
diff --git a/src/renderer/runtime/view/renderer/shaders/default.fs b/src/renderer/runtime/view/renderer/shaders/default.fs
new file mode 100644
index 0000000..2c8ad15
--- /dev/null
+++ b/src/renderer/runtime/view/renderer/shaders/default.fs
@@ -0,0 +1,10 @@
+precision highp float;
+
+varying vec2 vTextureCoord;
+
+uniform sampler2D uSampler;
+
+
+void main(void) {
+	gl_FragColor = texture2D(uSampler, vTextureCoord);
+}
diff --git a/src/renderer/runtime/view/renderer/shaders/default.vs b/src/renderer/runtime/view/renderer/shaders/default.vs
new file mode 100644
index 0000000..4715a17
--- /dev/null
+++ b/src/renderer/runtime/view/renderer/shaders/default.vs
@@ -0,0 +1,13 @@
+attribute vec2 aVertexPos;
+attribute vec2 aTextureCoord;
+
+uniform mat4 uViewport;
+uniform vec2 uTranslate;
+
+varying highp vec2 vTextureCoord;
+
+
+void main(void) {
+	gl_Position = uViewport * vec4(aVertexPos + uTranslate, 0.0, 1.0);
+	vTextureCoord = aTextureCoord;
+}