view: more refactoring

1 files changed, 29 insertions, 0 deletions

diff --git a/src/view/util/image.ts b/src/view/util/image.ts
new file mode 100644
index 0000000..50debde
--- /dev/null
+++ b/src/view/util/image.ts
@@ -0,0 +1,29 @@
+import { mapValuesAsync } from '../../util';
+
+export function loadImage(url: string): Promise<HTMLImageElement> {
+	return new Promise((resolve, reject) => {
+		const img = new Image();
+		img.addEventListener('load', () => { resolve(img); });
+		img.addEventListener('error', () => { reject(new Error('failed to load ' + url)); });
+		img.src = url;
+	});
+}
+
+export function loadImages(urls: Map<string, string>): Promise<Map<string, HTMLImageElement>> {
+	return mapValuesAsync(loadImage, urls);
+}
+
+export function mkTexture(gl: WebGLRenderingContext, src: HTMLCanvasElement|HTMLImageElement): WebGLTexture {
+	const texture = gl.createTexture();
+	if (!texture)
+		throw new Error('unable to create texture');
+
+	gl.bindTexture(gl.TEXTURE_2D, texture);
+	gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, src);
+	gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
+	gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
+	gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
+	gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
+
+	return texture;
+}