/*
* Copyright 2015-2017 WorldWind Contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @exports FramebufferTexture
*/
define([
'../error/ArgumentError',
'../util/Logger',
'../util/WWMath'
],
function (ArgumentError,
Logger) {
"use strict";
/**
* Constructs a framebuffer texture with the specified dimensions and an optional depth buffer. Use the
* [DrawContext.bindFramebuffer]{@link DrawContext#bindFramebuffer} function to make the program current during rendering.
*
* @alias FramebufferTexture
* @constructor
* @classdesc Represents an off-screen WebGL framebuffer. The framebuffer has color buffer stored in a 32
* bit RGBA texture, and has an optional depth buffer of at least 16 bits. Applications typically do not
* interact with this class. WebGL framebuffers are created by instances of this class and made current when the
* DrawContext.bindFramebuffer function is invoked.
* @param {WebGLRenderingContext} gl The current WebGL rendering context.
* @param {Number} width The width of the framebuffer, in pixels.
* @param {Number} height The height of the framebuffer, in pixels.
* @param {Boolean} depth true to configure the framebuffer with a depth buffer of at least 16 bits, false to
* disable depth buffering.
* @throws {ArgumentError} If the specified draw context is null or undefined, or if the width or height is less
* than zero.
*/
var FramebufferTexture = function (gl, width, height, depth) {
if (!gl) {
throw new ArgumentError(Logger.logMessage(Logger.LEVEL_SEVERE, "FramebufferTexture", "constructor",
"missingGlContext"));
}
if (width < 0 || height < 0) {
throw new ArgumentError(Logger.logMessage(Logger.LEVEL_SEVERE, "FramebufferTexture", "constructor",
"The framebuffer width or height is less than zero."));
}
/**
* The width of this framebuffer, in pixels.
* @type {Number}
* @readonly
*/
this.width = width;
/**
* The height of this framebuffer, in pixels.
* @type {Number}
* @readonly
*/
this.height = height;
/**
* Indicates whether or not this framebuffer has a depth buffer.
* @type {Boolean}
* @readonly
*/
this.depth = depth;
/**
* Indicates the size of this framebuffer's WebGL resources, in bytes.
* @type {Number}
* @readonly
*/
this.size = (width * height * 4) + (depth ? width * height * 2 : 0);
/**
* Indicates the WebGL framebuffer object object associated with this framebuffer texture.
* @type {WebGLFramebuffer}
* @readonly
*/
this.framebufferId = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, this.framebufferId);
// Internal. Intentionally not documented. Configure this framebuffer's color buffer.
this.texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, this.texture);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER,
gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER,
gl.LINEAR);
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.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0,
gl.RGBA, gl.UNSIGNED_BYTE, null);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0,
gl.TEXTURE_2D, this.texture, 0);
// Internal. Intentionally not documented. Configure this framebuffer's optional depth buffer.
this.depthBuffer = null;
if (depth) {
this.depthBuffer = gl.createRenderbuffer();
gl.bindRenderbuffer(gl.RENDERBUFFER, this.depthBuffer);
gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16,
width, height);
gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT,
gl.RENDERBUFFER, this.depthBuffer);
}
var e = gl.checkFramebufferStatus(gl.FRAMEBUFFER);
if (e != gl.FRAMEBUFFER_COMPLETE) {
Logger.logMessage(Logger.LEVEL_WARNING, "FramebufferTexture", "constructor",
"Error creating framebuffer: " + e);
this.framebufferId = null;
this.texture = null;
this.depthBuffer = null;
}
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
gl.bindRenderbuffer(gl.RENDERBUFFER, null);
gl.bindTexture(gl.TEXTURE_2D, null);
};
/**
* Binds this off-screen framebuffer's texture in the current WebGL graphics context. This texture contains
* color fragments resulting from WebGL operations executed when this framebuffer is bound by a call to
* [FramebufferTexture.bindFramebuffer]{@link FramebufferTexture#bindFramebuffer}.
*
* @param {DrawContext} dc The current draw context.
* @returns {Boolean} true if this framebuffer's texture was bound successfully, otherwise false.
*/
FramebufferTexture.prototype.bind = function (dc) {
if (this.texture) {
dc.currentGlContext.bindTexture(gl.TEXTURE_2D, this.texture);
}
return !!this.texture;
};
return FramebufferTexture;
});