Archive commit

src/ts/graphics/webgl/texture2d.ts

@@ -0,0 +1,98 @@
+type WebGL = WebGLRenderingContext;
+type Pixels = ImageBitmap | ImageData | HTMLVideoElement | HTMLImageElement | HTMLCanvasElement;
+
+export interface Texture2D {
+	handle: WebGLTexture;
+	width: number;
+	height: number;
+	format: number;
+	type: number;
+}
+
+export function createEmptyTexture(gl: WebGL, width: number, height: number, format?: number, type?: number): Texture2D {
+	if (format === undefined) {
+		format = gl.RGBA;
+	}
+
+	if (type === undefined) {
+		type = gl.UNSIGNED_BYTE;
+	}
+
+	const maxTextureSize = gl.getParameter(gl.MAX_TEXTURE_SIZE) as number | null;
+
+	if (maxTextureSize != null && (width < 0 || width > maxTextureSize || height < 0 || height > maxTextureSize)) {
+		throw new Error('Invalid texture shape');
+	}
+
+	if (type === gl.FLOAT && !gl.getExtension('OES_texture_float')) {
+		throw new Error('Floating point textures not supported on this platform');
+	}
+
+	const handle = createTextureHandle(gl);
+	gl.texImage2D(gl.TEXTURE_2D, 0, format, width, height, 0, format, type, null);
+	return { handle, width, height, format, type };
+}
+
+export function createTexture(gl: WebGL, data: Pixels, format?: number, type?: number): Texture2D {
+	if (format === undefined) {
+		format = gl.RGBA;
+	}
+
+	if (type === undefined) {
+		type = gl.UNSIGNED_BYTE;
+	}
+
+	const handle = createTextureHandle(gl);
+	gl.texImage2D(gl.TEXTURE_2D, 0, format, format, type, data);
+	return { handle, width: data.width, height: data.height, format, type };
+}
+
+export function disposeTexture(gl: WebGL | undefined, texture: Texture2D | undefined): undefined {
+	try {
+		if (gl && texture) {
+			gl.deleteTexture(texture.handle);
+		}
+	} catch (e) {
+		DEVELOPMENT && console.error(e);
+	}
+
+	return undefined;
+}
+
+export function bindTexture(gl: WebGL, unit: number, texture: Texture2D | undefined) {
+	gl.activeTexture(gl.TEXTURE0 + unit);
+	gl.bindTexture(gl.TEXTURE_2D, texture ? texture.handle : null);
+}
+
+export function resizeTexture(gl: WebGL, texture: Texture2D, width: number, height: number) {
+	width = width | 0;
+	height = height | 0;
+
+	const { format, type } = texture;
+	const maxSize = gl.getParameter(gl.MAX_TEXTURE_SIZE) as number | null;
+
+	if (maxSize != null && (width < 0 || width > maxSize || height < 0 || height > maxSize)) {
+		throw new Error('Invalid texture size');
+	}
+
+	texture.width = width;
+	texture.height = height;
+	gl.bindTexture(gl.TEXTURE_2D, texture.handle);
+	gl.texImage2D(gl.TEXTURE_2D, 0, format, width, height, 0, format, type, null);
+}
+
+function createTextureHandle(gl: WebGL) {
+	const texture = gl.createTexture();
+
+	if (!texture) {
+		throw new Error('Failed to create texture');
+	}
+
+	gl.bindTexture(gl.TEXTURE_2D, texture);
+	gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
+	gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
+	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);
+
+	return texture;
+}