// js/main.js
const canvas = document.getElementById('webgl-canvas');
const gl = canvas.getContext('webgl');
if (!gl) {
console.error('WebGL not supported');
alert('WebGL not supported');
}
gl.viewport(0, 0, canvas.width, canvas.height);
gl.clearColor(0.0, 0.0, 0.0, 1.0);
gl.clear(gl.COLOR_BUFFER_BIT);
const vertexShaderSource = `
attribute vec4 a_position;
void main(void) {
gl_Position = a_position;
}
`;
const fragmentShaderSource = `
void main(void) {
gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
}
`;
function compileShader(gl, source, type) {
const shader = gl.createShader(type);
gl.shaderSource(shader, source);
gl.compileShader(shader);
if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
console.error('Shader compile error:',
gl.getShaderInfoLog(shader));
gl.deleteShader(shader);
return null;
}
return shader;
}
const vertexShader = compileShader(gl,
vertexShaderSource, gl.VERTEX_SHADER);
const fragmentShader = compileShader(gl,
fragmentShaderSource, gl.FRAGMENT_SHADER);
const program = gl.createProgram();
gl.attachShader(program, vertexShader);
gl.attachShader(program, fragmentShader);
gl.linkProgram(program);
if (!gl.getProgramParameter(program, gl.LINK_STATUS)) {
console.error('Program link error:', gl.getProgramInfoLog(program));
}
gl.useProgram(program);
const vertices = new Float32Array([
0.0, 1.0, 0.0,
-1.0, -1.0, 0.0,
1.0, -1.0, 0.0
]);
const buffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
gl.bufferData(gl.ARRAY_BUFFER, vertices, gl.STATIC_DRAW);
const positionLocation = gl.getAttribLocation(program, 'a_position');
gl.enableVertexAttribArray(positionLocation);
gl.vertexAttribPointer(positionLocation, 3, gl.FLOAT, false, 0, 0);
gl.drawArrays(gl.TRIANGLES, 0, vertices.length / 3);