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<!--
Copyright (c) 2019 The Khronos Group Inc.
Use of this source code is governed by an MIT-style license that can be
found in the LICENSE.txt file.
-->
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>WebGL Enable Vertex Attrib Zero Test</title>
<link rel="stylesheet" href="../../resources/js-test-style.css"/>
<script src="../../js/js-test-pre.js"></script>
<script src="../../js/webgl-test-utils.js"> </script>
</head>
<body>
<canvas id="example" width="50" height="50">
</canvas>
<div id="description"></div>
<div id="console"></div>
<script id="vshader" type="x-shader/x-vertex">
attribute vec4 vPosition;
void main()
{
gl_Position = vPosition;
}
</script>
<script id="fshader" type="x-shader/x-fragment">
void main()
{
gl_FragColor = vec4(0.0,1.0,0.0,1.0);
}
</script>
<script>
"use strict";
description("Test some of the issues of the difference between attrib 0 on OpenGL vs WebGL");
debug("");
var wtu = WebGLTestUtils;
var gl = wtu.create3DContext("example");
var g_program;
var g_attribLocation;
function setup(attribIndex) {
var program = wtu.setupProgram(
gl, ['vshader', 'fshader'], ['vPosition'], [attribIndex]);
g_program = program;
g_attribLocation = attribIndex;
shouldBe("g_attribLocation", "gl.getAttribLocation(g_program, 'vPosition')");
return program;
}
function setupVerts(numVerts) {
var verts = [
1.0, 1.0, 0.0,
-1.0, 1.0, 0.0,
-1.0, -1.0, 0.0,
1.0, 1.0, 0.0,
-1.0, -1.0, 0.0,
1.0, -1.0, 0.0
];
var positions = new Float32Array(numVerts * 3);
var indices = new Uint16Array(numVerts);
for (var ii = 0; ii < numVerts; ++ii) {
var ndx = ii % 6;
var dst = ii * 3;
var src = ndx * 3;
for (var jj = 0; jj < 3; ++jj) {
positions[dst + jj] = verts[src + jj];
}
indices[ii] = ii;
}
var vertexObject = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
gl.bufferData(gl.ARRAY_BUFFER, positions, gl.STATIC_DRAW);
var indexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexBuffer);
gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
}
var p0 = setup(0);
var p3 = setup(3);
setupVerts(60000);
for (var ii = 0; ii < 5; ++ii) {
// test drawing with attrib 0
gl.useProgram(p0);
gl.enableVertexAttribArray(0);
gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.drawElements(gl.TRIANGLES, 60000, gl.UNSIGNED_SHORT, 0);
wtu.glErrorShouldBe(
gl, gl.NO_ERROR,
"drawing using attrib 0 with 6 verts");
wtu.checkCanvas(gl, [0, 255, 0, 255], "canvas should be green");
gl.disableVertexAttribArray(0);
// test drawing without attrib 0
gl.useProgram(p3);
gl.enableVertexAttribArray(3);
gl.vertexAttribPointer(3, 3, gl.FLOAT, false, 0, 0);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.drawArrays(gl.TRIANGLES, 0, 60000);
wtu.glErrorShouldBe(
gl, gl.NO_ERROR,
"drawing using attrib 3 with 60000 verts");
wtu.checkCanvas(gl, [0, 255, 0, 255], "canvas should be green");
gl.disableVertexAttribArray(3);
// This second test of drawing without attrib0 uncovered a bug in chrome
// where after the draw without attrib0 the attrib 0 emulation code disabled
// attrib 0 and it was never re-enabled so this next draw failed.
gl.useProgram(p3);
gl.enableVertexAttribArray(3);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.drawElements(gl.TRIANGLES, 60000, gl.UNSIGNED_SHORT, 0);
wtu.glErrorShouldBe(
gl, gl.NO_ERROR,
"drawing using attrib 3 with 60000 verts");
wtu.checkCanvas(gl, [0, 255, 0, 255], "canvas should be green");
gl.disableVertexAttribArray(3);
}
var successfullyParsed = true;
</script>
<script src="../../js/js-test-post.js"></script>
</body>
</html>
|
