some preparative refactoring for #1172

src/index.js

@@ -20,7 +20,7 @@ import Body from "./physics/body.js";
 import Bounds from "./physics/bounds.js";
 import Tween from "./tweens/tween.js";
 import GLShader from "./video/webgl/glshader.js";
-import WebGLCompositor from "./video/webgl/webgl_compositor.js";
+import WebGLCompositor from "./video/webgl/compositors/webgl_compositor.js";
 import Renderer from "./video/renderer.js";
 import WebGLRenderer from "./video/webgl/webgl_renderer.js";
 import CanvasRenderer from "./video/canvas/canvas_renderer.js";

src/video/webgl/compositors/compositor.js

@@ -0,0 +1,227 @@
+import * as event from "../../../system/event.js";
+
+
+/**
+ * @classdesc
+ * A base Compositor object.
+ */
+ export default class Compositor {
+    /**
+     * @param {WebGLRenderer} renderer - the current WebGL renderer session
+     */
+    constructor (renderer) {
+        this.init(renderer);
+    }
+
+    /**
+     * Initialize the compositor
+     * @ignore
+     */
+    init (renderer) {
+        // local reference
+        var gl = renderer.gl;
+
+        // the associated renderer
+        this.renderer = renderer;
+
+        // WebGL context
+        this.gl = renderer.gl;
+
+        // Global fill color
+        this.color = renderer.currentColor;
+
+        // Global transformation matrix
+        this.viewMatrix = renderer.currentTransform;
+
+        /**
+         * a reference to the active WebGL shader
+         * @type {GLShader}
+         */
+        this.activeShader = null;
+
+        /**
+         * primitive type to render (gl.POINTS, gl.LINE_STRIP, gl.LINE_LOOP, gl.LINES, gl.TRIANGLE_STRIP, gl.TRIANGLE_FAN, gl.TRIANGLES)
+         * @type {number}
+         * @default gl.TRIANGLES
+         */
+        this.mode = gl.TRIANGLES;
+
+        /**
+         * an array of vertex attribute properties
+         * @see WebGLCompositor.addAttribute
+         * @type {Array}
+         */
+        this.attributes = [];
+
+        /**
+         * the size of a single vertex in bytes
+         * (will automatically be calculated as attributes definitions are added)
+         * @see WebGLCompositor.addAttribute
+         * @type {number}
+         */
+        this.vertexByteSize = 0;
+
+        /**
+         * the size of a single vertex in floats
+         * (will automatically be calculated as attributes definitions are added)
+         * @see WebGLCompositor.addAttribute
+         * @type {number}
+         */
+        this.vertexSize = 0;
+
+        // register to the CANVAS resize channel
+        event.on(event.CANVAS_ONRESIZE, (width, height) => {
+            this.flush();
+            this.setViewport(0, 0, width, height);
+        });
+    }
+
+    /**
+     * Reset compositor internal state
+     * @ignore
+     */
+    reset() {
+        // WebGL context
+        this.gl = this.renderer.gl;
+
+        this.flush();
+
+        // initial viewport size
+        this.setViewport(
+            0, 0,
+            this.renderer.getCanvas().width,
+            this.renderer.getCanvas().height
+        );
+
+        // Initialize clear color
+        this.clearColor(0.0, 0.0, 0.0, 0.0);
+    }
+
+    /**
+     * add vertex attribute property definition to the compositor
+     * @param {string} name - name of the attribute in the vertex shader
+     * @param {number} size - number of components per vertex attribute. Must be 1, 2, 3, or 4.
+     * @param {GLenum} type - data type of each component in the array
+     * @param {boolean} normalized - whether integer data values should be normalized into a certain range when being cast to a float
+     * @param {number} offset - offset in bytes of the first component in the vertex attribute array
+     */
+    addAttribute(name, size, type, normalized, offset) {
+        this.attributes.push({
+            name: name,
+            size: size,
+            type: type,
+            normalized: normalized,
+            offset: offset
+        });
+
+        switch (type) {
+            case this.gl.BYTE:
+                this.vertexByteSize += size * Int8Array.BYTES_PER_ELEMENT;
+                break;
+            case this.gl.UNSIGNED_BYTE:
+                this.vertexByteSize += size * Uint8Array.BYTES_PER_ELEMENT;
+                break;
+            case this.gl.SHORT:
+                this.vertexByteSize += size * Int16Array.BYTES_PER_ELEMENT;
+                break;
+            case this.gl.UNSIGNED_SHORT:
+                this.vertexByteSize += size * Uint16Array.BYTES_PER_ELEMENT;
+                break;
+            case this.gl.INT:
+                this.vertexByteSize += size * Int32Array.BYTES_PER_ELEMENT;
+                break;
+            case this.gl.UNSIGNED_INT:
+                this.vertexByteSize += size * Uint32Array.BYTES_PER_ELEMENT;
+                break;
+            case this.gl.FLOAT:
+                this.vertexByteSize += size * Float32Array.BYTES_PER_ELEMENT;
+                break;
+            default:
+                throw new Error("Invalid GL Attribute type");
+        }
+        this.vertexSize = this.vertexByteSize / Float32Array.BYTES_PER_ELEMENT;
+    }
+
+    /**
+     * Sets the viewport
+     * @param {number} x - x position of viewport
+     * @param {number} y - y position of viewport
+     * @param {number} w - width of viewport
+     * @param {number} h - height of viewport
+     */
+    setViewport(x, y, w, h) {
+        this.gl.viewport(x, y, w, h);
+    }
+
+    /**
+     * set/change the current projection matrix
+     * @param {Matrix3d} matrix
+     */
+    setProjection(matrix) {
+        this.activeShader.setUniform("uProjectionMatrix", matrix);
+    }
+
+    /**
+     * Select the shader to use for compositing
+     * @see GLShader
+     * @param {GLShader} shader - a reference to a GLShader instance
+     */
+    useShader(shader) {
+        if (this.activeShader !== shader) {
+            this.flush();
+            this.activeShader = shader;
+            this.activeShader.bind();
+            this.activeShader.setUniform("uProjectionMatrix", this.renderer.projectionMatrix);
+            this.activeShader.setVertexAttributes(this.gl, this.attributes, this.vertexByteSize);
+        }
+    }
+
+    /**
+     * Flush batched texture operations to the GPU
+     * @param {number} [mode=gl.TRIANGLES] - the GL drawing mode
+     */
+    flush(mode = this.mode) {
+        var vertex = this.vertexBuffer;
+        var vertexCount = vertex.vertexCount;
+
+        if (vertexCount > 0) {
+            var gl = this.gl;
+            var vertexSize = vertex.vertexSize;
+
+            // Copy data into stream buffer
+            if (this.renderer.WebGLVersion > 1) {
+                gl.bufferData(gl.ARRAY_BUFFER, vertex.toFloat32(), gl.STREAM_DRAW, 0, vertexCount * vertexSize);
+            } else {
+                gl.bufferData(gl.ARRAY_BUFFER, vertex.toFloat32(0, vertexCount * vertexSize), gl.STREAM_DRAW);
+            }
+
+            gl.drawArrays(mode, 0, vertexCount);
+
+            // clear the vertex buffer
+            vertex.clear();
+        }
+    }
+
+    /**
+     * Clear the frame buffer
+     * @param {number} [alpha = 0.0] - the alpha value used when clearing the framebuffer
+     */
+    clear(alpha = 0) {
+        var gl = this.gl;
+        gl.clearColor(0, 0, 0, alpha);
+        gl.clear(gl.COLOR_BUFFER_BIT | gl.STENCIL_BUFFER_BIT);
+    }
+
+    /**
+     * Specify the color values used when clearing color buffers. The values are clamped between 0 and 1.
+     * @param {number} [r = 0] - the red color value used when the color buffers are cleared
+     * @param {number} [g = 0] - the green color value used when the color buffers are cleared
+     * @param {number} [b = 0] - the blue color value used when the color buffers are cleared
+     * @param {number} [a = 0] - the alpha color value used when the color buffers are cleared
+     */
+    clearColor(r = 0, g = 0, b = 0, a = 0) {
+        var gl = this.gl;
+        gl.clearColor(r, g, b, a);
+        gl.clear(gl.COLOR_BUFFER_BIT);
+    }
+}