public static WebGLShader createShader(int type, String code, WebGLRenderingContext ctx) {
WebGLShader shader = ctx.createShader(type);
ctx.shaderSource(shader, code);
ctx.compileShader(shader);
if (testShaderStatus(ctx, shader)) return shader;
// else error
String lastError = ctx.getShaderInfoLog(shader);
Window.alert("*** Error compiling shader '" + shader + "':" + lastError);
ctx.deleteShader(shader);
return null;
}
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;
}
private static boolean testShaderStatus(WebGLRenderingContext ctx, WebGLShader shader) {
Any a = ctx.getShaderParameter(shader, WebGLRenderingContext.COMPILE_STATUS);
return a.getBoolean();
}