46 lines
1.6 KiB
JavaScript
46 lines
1.6 KiB
JavaScript
// Compile a WebGL program from a vertex shader and a fragment shader
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compile = (gl, vshader, fshader) => {
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var vs = gl.createShader(gl.VERTEX_SHADER);
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gl.shaderSource(vs, vshader);
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gl.compileShader(vs);
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var fs = gl.createShader(gl.FRAGMENT_SHADER);
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gl.shaderSource(fs, fshader);
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gl.compileShader(fs);
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var program = gl.createProgram();
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gl.attachShader(program, vs);
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gl.attachShader(program, fs);
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gl.linkProgram(program);
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gl.useProgram(program);
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console.log('vertex shader:', gl.getShaderInfoLog(vs) || 'OK');
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console.log('fragment shader:', gl.getShaderInfoLog(fs) || 'OK');
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console.log('program:', gl.getProgramInfoLog(program) || 'OK');
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return program;
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}
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// Bind a data buffer to an attribute, fill it with data and enable it
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buffer = (gl, data, program, attribute, size, type) => {
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gl.bindBuffer(gl.ARRAY_BUFFER, gl.createBuffer());
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gl.bufferData(gl.ARRAY_BUFFER, data, gl.STATIC_DRAW);
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var a = gl.getAttribLocation(program, attribute);
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gl.vertexAttribPointer(a, size, type, false, 0, 0);
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gl.enableVertexAttribArray(a);
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}
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// Draw a box
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drawBox = (gl, n, viewProjMatrix, u_MvpMatrix, u_NormalMatrix) => {
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// Compute mvp matrix
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g_mvpMatrix.set(viewProjMatrix);
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g_mvpMatrix.multiply(g_modelMatrix);
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gl.uniformMatrix4fv(u_MvpMatrix, false, g_mvpMatrix.elements);
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// Compute inverse transform
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g_normalMatrix.setInverseOf(g_modelMatrix);
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g_normalMatrix.transpose();
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gl.uniformMatrix4fv(u_NormalMatrix, false, g_normalMatrix.elements);
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// Draw
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gl.drawElements(gl.TRIANGLES, n, gl.UNSIGNED_BYTE, 0);
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}
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