starling-framework
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A fast, productive library for 2D cross-platform development.
158 lines (149 loc) • 7.92 kB
TypeScript
import SubTexture from "./../../starling/textures/SubTexture";
import Starling from "./../../starling/core/Starling";
import Rectangle from "openfl/geom/Rectangle";
import IllegalOperationError from "openfl/errors/IllegalOperationError";
import Texture from "./../../starling/textures/Texture";
import Image from "./../../starling/display/Image";
import DisplayObject from "./../display/DisplayObject";
import Vector3D from "openfl/geom/Vector3D";
import Matrix from "openfl/geom/Matrix";
declare namespace starling.textures
{
/** A RenderTexture is a any texture onto which you can draw any display object.
*
* <p>After creating a render texture, just call the <code>draw</code> method to render
* an object directly onto the texture. The object will be drawn onto the texture at its current
* position, adhering its current rotation, scale and alpha properties.</p>
*
* <p>Drawing is done very efficiently, as it is happening directly in graphics memory. After
* you have drawn objects onto the texture, the performance will be just like that of a normal
* texture — no matter how many objects you have drawn.</p>
*
* <p>If you draw lots of objects at once, it is recommended to bundle the drawing calls in
* a block via the <code>drawBundled</code> method, like shown below. That will speed it up
* immensely, allowing you to draw hundreds of objects very quickly.</p>
*
* <pre>
* renderTexture.drawBundled(function():void
* {
* for (i?:number; i<numDrawings; ++i)
* {
* image.rotation = (2 * Math.PI / numDrawings) * i;
* renderTexture.draw(image);
* }
* });
* </pre>
*
* <p>To erase parts of a render texture, you can use any display object like a "rubber" by
* setting its blending mode to <code>BlendMode.ERASE</code>. To wipe it completely clean,
* use the <code>clear</code> method.</p>
*
* <strong>Persistence</strong>
*
* <p>Older devices may require double buffering to support persistent render textures. Thus,
* you should disable the <code>persistent</code> parameter in the constructor if you only
* need to make one draw operation on the texture. The static <code>useDoubleBuffering</code>
* property allows you to customize if new textures will be created with or without double
* buffering.</p>
*
* <strong>Context Loss</strong>
*
* <p>Unfortunately, render textures are wiped clean when the render context is lost.
* This means that you need to manually recreate all their contents in such a case.
* One way to do that is by using the <code>root.onRestore</code> callback, like here:</p>
*
* <listing>
* renderTexture.root.onRestore = function():void
* {
* quad:Quad = new Quad(100, 100, 0xff00ff);
* renderTexture.clear(); // required on texture restoration
* renderTexture.draw(quad);
* });</listing>
*
* <p>For example, a drawing app would need to store information about all draw operations
* when they occur, and then recreate them inside <code>onRestore</code> on a context loss
* (preferably using <code>drawBundled</code> instead).</p>
*
* <p>However, there is one problem: when that callback is executed, it's very likely that
* not all of your textures are already available, since they need to be restored, too (and
* that might take a while). You probably loaded your textures with the "AssetManager".
* In that case, you can listen to its <code>TEXTURES_RESTORED</code> event instead:</p>
*
* <listing>
* assetManager.addEventListener(Event.TEXTURES_RESTORED, function():void
* {
* brush:Image = new Image(assetManager.getTexture("brush"));
* renderTexture.draw(brush);
* });</listing>
*
* <p>[Note that this time, there is no need to call <code>clear</code>, because that's the
* default behavior of <code>onRestore</code>, anyway — and we didn't modify that.]</p>
*
*/
export class RenderTexture extends SubTexture
{
/** Creates a new RenderTexture with a certain size (in points). If the texture is
* persistent, its contents remains intact after each draw call, allowing you to use the
* texture just like a canvas. If it is not, it will be cleared before each draw call.
*
* <p>Non-persistent textures can be used more efficiently on older devices; on modern
* hardware, it does not make a difference. For more information, have a look at the
* documentation of the <code>useDoubleBuffering</code> property.</p>
*/
public constructor(width:number, height:number, persistent?:boolean,
scale?:number, format?:string);
/** @inheritDoc */
public /*override*/ dispose():void;
/** Draws an object into the texture.
*
* @param object The object to draw.
* @param matrix If 'matrix' is null, the object will be drawn adhering its
* properties for position, scale, and rotation. If it is not null,
* the object will be drawn in the orientation depicted by the matrix.
* @param alpha The object's alpha value will be multiplied with this value.
* @param antiAliasing Values range from 0 (no antialiasing) to 4 (best quality).
* Beginning with AIR 22, this feature is supported on all platforms
* (except for software rendering mode).
* @param cameraPos When drawing a 3D object, you can optionally pass in a custom
* camera position. If left empty, the camera will be placed with
* its default settings (centered over the texture, fov = 1.0).
*/
public draw(object:DisplayObject, matrix?:Matrix, alpha?:number,
antiAliasing?:number, cameraPos?:Vector3D):void;
/** Bundles several calls to <code>draw</code> together in a block. This avoids buffer
* switches and allows you to draw multiple objects into a non-persistent texture.
* Note that the 'antiAliasing' setting provided here overrides those provided in
* individual 'draw' calls.
*
* @param drawingBlock a callback with the form: <pre>function():void;</pre>
* @param antiAliasing Values range from 0 (no antialiasing) to 4 (best quality).
* Beginning with AIR 22, this feature is supported on all platforms
* (except for software rendering mode).
* @param cameraPos When drawing a 3D object, you can optionally pass in a custom
* camera position. If left empty, the camera will be placed with
* its default settings (centered over the texture, fov = 1.0).
*/
public drawBundled(drawingBlock:()=>void, antiAliasing?:number,
cameraPos?:Vector3D):void;
/** Clears the render texture with a certain color and alpha value. Call without any
* arguments to restore full transparency. */
public clear(color?:number, alpha?:number):void;
// properties
/** Indicates if the texture is persistent over multiple draw calls. */
public readonly isPersistent:boolean;
protected get_isPersistent():boolean;
/** Indicates if new persistent textures should use double buffering. Single buffering
* is faster and requires less memory, but is not supported on all hardware.
*
* <p>By default, applications running with the profile "baseline" or "baselineConstrained"
* will use double buffering; all others use just a single buffer. You can override this
* behavior, though, by assigning a different value at runtime.</p>
*
* @default true for "baseline" and "baselineConstrained", false otherwise
*/
public static useDoubleBuffering:boolean;
protected static get_useDoubleBuffering():boolean;
protected static set_useDoubleBuffering(value:boolean):boolean;
}
}
export default starling.textures.RenderTexture;