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<!DOCTYPE HTML>
<html>
<head>
<meta charset='UTF-8'/>
<script src='/tests/SimpleTest/SimpleTest.js'></script>
<link rel='stylesheet' href='/tests/SimpleTest/test.css'>
<script src='../webgl-util.js'></script>
<script id='vs' type='x-shader/x-vertex'>
attribute vec2 aPosition;
void main(void) {
gl_PointSize = 16.0;
gl_Position = vec4(aPosition, 0, 1);
}
</script>
<script id='fs' type='x-shader/x-fragment'>
precision mediump float;
uniform vec4 uColor;
void main(void) {
gl_FragColor = uColor;
}
</script>
</head>
<body>
<script>
function GetPixel(gl, x, y) {
var pixel = new Uint8Array(4);
gl.readPixels(x, y, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, pixel);
return pixel;
}
function ColorStr(arr) {
return '{' + arr.map(function(x) { return '' + x; }).join(', ') + '}';
}
function PixelShouldBe(gl, x, y, ref, prefix) {
if (prefix) {
prefix += ': ';
}
var test = GetPixel(gl, x, y);
var testStr = ColorStr(test);
var refStr = ColorStr(ref.map(value => value * 255));
ok(testStr == refStr, prefix + 'Should be ' + refStr + ', was ' + testStr + '.');
}
function GetProgram(gl) {
var prog = WebGLUtil.createProgramByIds(gl, 'vs', 'fs');
prog.aPosition = gl.getAttribLocation(prog, 'aPosition');
ok(prog.aPosition >= 0, '`aPosition` should be valid.');
prog.uColor = gl.getUniformLocation(prog, 'uColor');
ok(prog.uColor, '`uColor` should be valid.');
return prog;
}
// Give ourselves a scope to return early from:
(function () {
var c = document.createElement('canvas');
document.body.appendChild(c);
var gl = c.getContext('webgl', { depth: false, antialias: false });
if (!gl) {
todo(false, 'WebGL is unavailable.');
return;
}
////////
// With default culling, it works fine.
// The problem seems to be that the virtual quads generated from points are wound 'backwards'.
gl.enable(gl.CULL_FACE);
gl.cullFace(gl.BACK); // Cull back faces.
////////
var vertArr = new Float32Array([
-1, -1,
+1, -1,
-1, +1,
]);
var vbo = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, vbo);
gl.bufferData(gl.ARRAY_BUFFER, vertArr, gl.STATIC_DRAW);
////////
var triProg = GetProgram(gl);
var pointProg = GetProgram(gl);
if (!triProg || !pointProg) {
ok(false, 'Program linking should succeed.');
return;
}
ok(triProg.aPosition == pointProg.aPosition, 'aPosition should match.');
gl.enableVertexAttribArray(triProg.aPosition);
gl.vertexAttribPointer(triProg.aPosition, 2, gl.FLOAT, false, 0, 0);
////////
gl.useProgram(triProg);
var triColor = [1, 0, 0, 1];
gl.uniform4fv(triProg.uColor, triColor);
gl.useProgram(pointProg);
var pointColor = [0, 1, 0, 1];
gl.uniform4fv(pointProg.uColor, pointColor);
////////
gl.clearColor(0, 0, 0, 1);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.useProgram(triProg);
gl.drawArrays(gl.TRIANGLES, 0, 3);
gl.useProgram(pointProg);
gl.drawArrays(gl.POINTS, 0, 3);
////////
PixelShouldBe(gl, 32, 32, triColor, 'Tri');
PixelShouldBe(gl, 0, 0, pointColor, 'Point');
ok(true, 'Test complete');
})();
</script>
</body>
</html>
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