/*
* Copyright 2003-2006, 2009, 2017, United States Government, as represented by the Administrator of the
* National Aeronautics and Space Administration. All rights reserved.
*
* The NASAWorldWind/WebWorldWind platform is 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 ScreenImage
*/
define([
'../error/ArgumentError',
'../shaders/BasicTextureProgram',
'../util/Color',
'../util/ImageSource',
'../util/Logger',
'../geom/Matrix',
'../util/Offset',
'../pick/PickedObject',
'../render/Renderable',
'../geom/Vec3',
'../util/WWMath'
],
function (ArgumentError,
BasicTextureProgram,
Color,
ImageSource,
Logger,
Matrix,
Offset,
PickedObject,
Renderable,
Vec3,
WWMath) {
"use strict";
/**
* Constructs a screen image.
* @alias ScreenImage
* @constructor
* @augments Renderable
* @classdesc Displays an image at a specified screen location in the WorldWindow.
* The image location is specified by an offset, which causes the image to maintain its relative position
* when the window size changes.
* @param {Offset} screenOffset The offset indicating the image's placement on the screen.
* Use [the image offset property]{@link ScreenImage#imageOffset} to position the image relative to the
* specified screen offset.
* @param {String|ImageSource} imageSource The source of the image to display.
* May be either a string identifying the URL of the image, or an {@link ImageSource} object identifying a
* dynamically created image.
* @throws {ArgumentError} If the specified screen offset or image source is null or undefined.
*/
var ScreenImage = function (screenOffset, imageSource) {
if (!screenOffset) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "ScreenImage", "constructor", "missingOffset"));
}
if (!imageSource) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "ScreenImage", "constructor", "missingImage"));
}
Renderable.call(this);
/**
* The offset indicating this screen image's placement on the screen.
* @type {Offset}
*/
this.screenOffset = screenOffset;
// Documented with its property accessor below.
this._imageSource = imageSource;
/**
* The image color. When displayed, this shape's image is multiplied by this image color to achieve the
* final image color. The color white, the default, causes the image to be drawn in its native colors.
* @type {Color}
* @default White (1, 1, 1, 1)
*/
this.imageColor = Color.WHITE;
/**
* Indicates the location within the image at which to align with the specified screen location.
* May be null, in which case the image's bottom-left corner is placed at the screen location.
* @type {Offset}
* @default 0.5, 0.5, both fractional (Centers the image on the screen location.)
*/
this.imageOffset = new Offset(WorldWind.OFFSET_FRACTION, 0.5, WorldWind.OFFSET_FRACTION, 0.5);
/**
* Indicates the amount to scale the image.
* @type {Number}
* @default 1
*/
this.imageScale = 1;
/**
* The amount of rotation to apply to the image, measured in degrees clockwise from the top of the window.
* @type {Number}
* @default 0
*/
this.imageRotation = 0;
/**
* The amount of tilt to apply to the image, measured in degrees.
* @type {Number}
* @default 0
*/
this.imageTilt = 0;
/**
* Indicates whether to draw this screen image.
* @type {Boolean}
* @default true
*/
this.enabled = true;
/**
* This image's opacity. When this screen image is drawn, the actual opacity is the product of
* this opacity and the opacity of the layer containing this screen image.
* @type {Number}
*/
this.opacity = 1;
/**
* Indicates the object to return as the userObject of this shape when picked. If null,
* then this shape is returned as the userObject.
* @type {Object}
* @default null
* @see [PickedObject.userObject]{@link PickedObject#userObject}
*/
this.pickDelegate = null;
// Internal use only. Intentionally not documented.
this.activeTexture = null;
// Internal use only. Intentionally not documented.
this.imageTransform = Matrix.fromIdentity();
// Internal use only. Intentionally not documented.
this.texCoordMatrix = Matrix.fromIdentity();
// Internal use only. Intentionally not documented.
this.imageBounds = null;
// Internal use only. Intentionally not documented.
this.layer = null;
};
// Internal use only. Intentionally not documented.
ScreenImage.matrix = Matrix.fromIdentity(); // scratch variable
ScreenImage.prototype = Object.create(Renderable.prototype);
Object.defineProperties(ScreenImage.prototype, {
/**
* The source of the image to display.
* May be either a string identifying the URL of the image, or an {@link ImageSource} object identifying a
* dynamically created image.
* @type {String|ImageSource}
* @default null
* @memberof ScreenImage.prototype
*/
imageSource: {
get: function () {
return this._imageSource;
},
set: function (imageSource) {
if (!imageSource) {
throw new ArgumentError(Logger.logMessage(Logger.LEVEL_SEVERE, "ScreenImage", "imageSource",
"missingImage"));
}
this._imageSource = imageSource;
this.imageSourceWasUpdated = true;
}
}
});
/**
* Renders this screen image. This method is typically not called by applications but is called by
* {@link RenderableLayer} during rendering. For this shape this method creates and
* enques an ordered renderable with the draw context and does not actually draw the image.
* @param {DrawContext} dc The current draw context.
*/
ScreenImage.prototype.render = function (dc) {
if (!this.enabled) {
return;
}
if (!dc.accumulateOrderedRenderables) {
return;
}
// Create an ordered renderable, but don't create more than one per frame.
var orderedScreenImage = null;
if (this.lastFrameTime !== dc.timestamp) {
orderedScreenImage = this.makeOrderedRenderable(dc);
}
if (!orderedScreenImage) {
return;
}
if (!orderedScreenImage.isVisible(dc)) {
return;
}
orderedScreenImage.layer = dc.currentLayer;
this.lastFrameTime = dc.timestamp;
dc.addOrderedRenderable(orderedScreenImage);
};
/**
* Draws this shape as an ordered renderable. Applications do not call this function. It is called by
* [WorldWindow]{@link WorldWindow} during rendering.
* @param {DrawContext} dc The current draw context.
*/
ScreenImage.prototype.renderOrdered = function (dc) {
this.drawOrderedScreenImage(dc);
if (dc.pickingMode) {
var po = new PickedObject(this.pickColor.clone(), this.pickDelegate ? this.pickDelegate : this,
null, this.layer, false);
dc.resolvePick(po);
}
};
// Internal. Intentionally not documented.
ScreenImage.prototype.makeOrderedRenderable = function (dc) {
var w, h, s, ws, hs,
iOffset, sOffset;
this.activeTexture = this.getActiveTexture(dc);
if (!this.activeTexture || this.imageSourceWasUpdated) {
this.activeTexture = dc.gpuResourceCache.retrieveTexture(dc.currentGlContext, this._imageSource);
if (!this.activeTexture) {
return null;
}
}
this.eyeDistance = 0;
// Compute the image's transform matrix and texture coordinate matrix according to its screen point, image size,
// image offset and image scale. The image offset is defined with its origin at the image's bottom-left corner and
// axes that extend up and to the right from the origin point.
w = this.activeTexture.imageWidth;
h = this.activeTexture.imageHeight;
s = this.imageScale;
iOffset = this.imageOffset.offsetForSize(w, h);
ws = dc.viewport.width;
hs = dc.viewport.height;
sOffset = this.screenOffset.offsetForSize(ws, hs);
this.imageTransform.setTranslation(
sOffset[0] - iOffset[0] * s,
sOffset[1] - iOffset[1] * s,
0);
this.imageTransform.setScale(w * s, h * s, 1);
this.imageBounds = WWMath.boundingRectForUnitQuad(this.imageTransform);
return this;
};
ScreenImage.prototype.getActiveTexture = function (dc) {
return dc.gpuResourceCache.resourceForKey(this._imageSource);
};
// Internal. Intentionally not documented.
ScreenImage.prototype.isVisible = function (dc) {
if (dc.pickingMode) {
return dc.pickRectangle && (this.imageBounds.intersects(dc.pickRectangle));
} else {
return this.imageBounds.intersects(dc.viewport);
}
};
// Internal. Intentionally not documented.
ScreenImage.prototype.drawOrderedScreenImage = function (dc) {
this.beginDrawing(dc);
try {
this.doDrawOrderedScreenImage(dc);
} finally {
this.endDrawing(dc);
}
};
// Internal. Intentionally not documented.
ScreenImage.prototype.beginDrawing = function (dc) {
var gl = dc.currentGlContext,
program;
dc.findAndBindProgram(BasicTextureProgram);
// Configure GL to use the draw context's unit quad VBOs for both model coordinates and texture coordinates.
// Most browsers can share the same buffer for vertex and texture coordinates, but Internet Explorer requires
// that they be in separate buffers, so the code below uses the 3D buffer for vertex coords and the 2D
// buffer for texture coords.
program = dc.currentProgram;
gl.bindBuffer(gl.ARRAY_BUFFER, dc.unitQuadBuffer());
gl.vertexAttribPointer(program.vertexTexCoordLocation, 2, gl.FLOAT, false, 0, 0);
gl.enableVertexAttribArray(program.vertexPointLocation);
gl.enableVertexAttribArray(program.vertexTexCoordLocation);
// Tell the program which texture unit to use.
program.loadTextureUnit(gl, gl.TEXTURE0);
program.loadModulateColor(gl, dc.pickingMode);
// Turn off depth testing.
gl.disable(gl.DEPTH_TEST);
};
// Internal. Intentionally not documented.
ScreenImage.prototype.endDrawing = function (dc) {
var gl = dc.currentGlContext,
program = dc.currentProgram;
// Clear the vertex attribute state.
gl.disableVertexAttribArray(program.vertexPointLocation);
gl.disableVertexAttribArray(program.vertexTexCoordLocation);
// Clear GL bindings.
gl.bindBuffer(gl.ARRAY_BUFFER, null);
gl.bindTexture(gl.TEXTURE_2D, null);
// Re-enable depth testing.
gl.enable(gl.DEPTH_TEST);
};
// Internal. Intentionally not documented.
ScreenImage.prototype.doDrawOrderedScreenImage = function (dc) {
var gl = dc.currentGlContext,
program = dc.currentProgram;
gl.bindBuffer(gl.ARRAY_BUFFER, dc.unitQuadBuffer3());
gl.vertexAttribPointer(program.vertexPointLocation, 3, gl.FLOAT, false, 0, 0);
// Compute and specify the MVP matrix.
ScreenImage.matrix.copy(dc.screenProjection);
ScreenImage.matrix.multiplyMatrix(this.imageTransform);
ScreenImage.matrix.multiplyByTranslation(0.5, 0.5, 0.5); // shift Z to prevent image clipping
ScreenImage.matrix.multiplyByRotation(1, 0, 0, this.imageTilt);
ScreenImage.matrix.multiplyByRotation(0, 0, 1, this.imageRotation);
ScreenImage.matrix.multiplyByTranslation(-0.5, -0.5, 0);
program.loadModelviewProjection(gl, ScreenImage.matrix);
// Enable texture for both normal display and for picking. If picking is enabled in the shader (set in
// beginDrawing() above) then the texture's alpha component is still needed in order to modulate the
// pick color to mask off transparent pixels.
program.loadTextureEnabled(gl, true);
// Set the pick color for picking or the color and opacity if not picking.
if (dc.pickingMode) {
this.pickColor = dc.uniquePickColor();
program.loadColor(gl, this.pickColor);
program.loadOpacity(gl, 1);
} else {
program.loadColor(gl, this.imageColor);
program.loadOpacity(gl, this.opacity * this.layer.opacity);
}
this.texCoordMatrix.setToIdentity();
this.texCoordMatrix.multiplyByTextureTransform(this.activeTexture);
program.loadTextureMatrix(gl, this.texCoordMatrix);
if (this.activeTexture.bind(dc)) { // returns false if active texture cannot be bound
// Draw the placemark's image quad.
gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);
}
};
return ScreenImage;
})
;