76 lines
2.2 KiB
JavaScript
76 lines
2.2 KiB
JavaScript
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// PendulumComponents.js
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// John Breaux 2022-06-30
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// Super-class for simple, flat-color drawn primitives
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"use strict"
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//
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// Classes
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//
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// ShapedObject: Super-class for simple drawn primitives
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class ShapedObject {
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constructor({ color = { r: 1, g: 1, b: 1, a: 0.5 } } = {}) {
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// Set object color
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this.color = [color.r, color.g, color.b, color.a];
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}
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// Convert to Float32Array [x, y]
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vertex_array() {
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// allocate space for center.xy + vertices.xy
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var ret = new Float32Array((this.vertices.length) * 2);
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// save the vertices
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for (var i = 0; i < this.vertices.length; i++) {
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var j = 2 * i;
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ret[j] = this.vertices[i].x;
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ret[j + 1] = this.vertices[i].y;
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}
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return ret;
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}
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// Generate the index_array for the shape
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index_array() {
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var ret = new Uint8Array(this.vertices.length + 1);
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for (var i = 0; i < this.vertices.length; i++) {
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ret[i] = i
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}
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ret[this.vertices.length] = 0;
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return ret;
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}
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// Initialize the object's drawing parameters
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init(gl) {
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// Make the buffers
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this.vertexBuffer = acquire_buffer(gl);
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this.indexBuffer = acquire_buffer(gl);
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// Bind the buffers
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gl.bindBuffer(gl.ARRAY_BUFFER, this.vertexBuffer);
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gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, this.indexBuffer);
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// Write date into the buffers
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gl.bufferData(gl.ARRAY_BUFFER, this.vertex_array(), gl.STATIC_DRAW);
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gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, this.index_array(), gl.STATIC_DRAW);
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}
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// Draw the object
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draw(gl, modelMatrix, u_ModelMatrix) {
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// Bind the buffers
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gl.bindBuffer(gl.ARRAY_BUFFER, this.vertexBuffer);
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gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, this.indexBuffer);
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// Set the object's color
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var u_Color = acquire_uniform(gl, 'u_Color');
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gl.uniform4fv(u_Color, this.color);
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// get a_Position
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enable_attribute(gl, 'a_Position', 2, gl.FLOAT);
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// Pass the rotation matrix to the vertex shader
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gl.uniformMatrix4fv(u_ModelMatrix, false, modelMatrix.elements);
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// Draw the Anchor
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gl.drawElements(this.draw_primitive, this.vertices.length, gl.UNSIGNED_BYTE, 0);
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}
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}
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// Give me your [HeartShapedObject]
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