draw from index

This commit is contained in:
monoid 2021-09-05 16:23:37 +09:00
parent d0252f94c9
commit 66326bca06

View File

@ -41,25 +41,35 @@ class Renderer{
else throw e;
}
}
init(){
const gl = this.gl;
const position = [
-0.5,-0.5,
0.5,-0.5,
0.5,0.5,
-0.5,0.5
];
const index = [
0,1,2,
2,3,0
];
const positionBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER,positionBuffer);
gl.bufferData(gl.ARRAY_BUFFER,new Float32Array(position),gl.STATIC_DRAW);
const indexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER,indexBuffer);
gl.bufferData(gl.ELEMENT_ARRAY_BUFFER,new Uint16Array(index),gl.STATIC_DRAW);
}
draw(){
const gl = this.gl;
gl.viewport(0,0,gl.canvas.width,gl.canvas.height);
const position = [
-0.5,-0.5,
0.0,0.5,
0.5,-0.5
];
let positionBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER,positionBuffer);
gl.enableVertexAttribArray(0);
gl.vertexAttribPointer(0,2,gl.FLOAT,false,0,0);
const floatPosition = new Float32Array(position);
gl.bufferData(gl.ARRAY_BUFFER,floatPosition,gl.STATIC_DRAW);
gl.drawArrays(gl.TRIANGLES,0,3);
gl.deleteBuffer(positionBuffer);
gl.drawElements(gl.TRIANGLES,6,gl.UNSIGNED_SHORT,0);
}
}
@ -67,7 +77,7 @@ function main(){
const canvas = findCanvas();
const gl = getGLContext(canvas);
const renderer = new Renderer(gl);
renderer.init()
window.addEventListener("resize",(e)=>{
e.preventDefault();
canvas.width = document.body.clientWidth;