public static WebGLProgram createAndUseProgram(
List<WebGLShader> shaders, WebGLRenderingContext ctx) {
WebGLProgram program = ctx.createProgram();
for (WebGLShader s : shaders) ctx.attachShader(program, s);
ctx.linkProgram(program);
if (ctx.getProgramParameter(program, WebGLRenderingContext.LINK_STATUS).getBoolean()) {
ctx.useProgram(program);
return program;
}
// else error
String lastError = ctx.getProgramInfoLog(program);
Window.alert("*** Error compiling program '" + program + "':" + lastError);
ctx.deleteProgram(program);
return null;
}