<!--
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 drawElements Test</title>
<link rel="stylesheet" href="../../resources/js-test-style.css"/>
<script src="../../js/desktop-gl-constants.js"></script>
<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(1.0,0.0,0.0,1.0);
}
</script>

<script>"use strict";
description(document.title);

var wtu = WebGLTestUtils;
var gl = wtu.create3DContext("example");
var program = wtu.setupProgram(gl, ["vshader", "fshader"], ["vPosition"]);

gl.bindBuffer(gl.ARRAY_BUFFER, gl.createBuffer());
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([ 0,0.5,0, -0.5,-0.5,0, 0.5,-0.5,0 ]), gl.STATIC_DRAW);
gl.enableVertexAttribArray(0);
gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 0, 0);

gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, gl.createBuffer());
gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array([ 0, 1, 2]), gl.STATIC_DRAW);
wtu.shouldGenerateGLError(gl, gl.NO_ERROR,
                          "gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_SHORT, 0)");

gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint8Array([ 0, 1, 2, 0]), gl.STATIC_DRAW);
wtu.shouldGenerateGLError(gl, gl.NO_ERROR,
                          "gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_BYTE, 0)");

wtu.shouldGenerateGLError(gl, gl.INVALID_ENUM,
                          "gl.drawElements(desktopGL.QUAD_STRIP, 4, gl.UNSIGNED_BYTE, 0)");
wtu.shouldGenerateGLError(gl, gl.INVALID_ENUM,
                          "gl.drawElements(desktopGL.QUADS, 4, gl.UNSIGNED_BYTE, 0)");
wtu.shouldGenerateGLError(gl, gl.INVALID_ENUM,
                          "gl.drawElements(desktopGL.POLYGON, 4, gl.UNSIGNED_BYTE, 0)");

gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint32Array([ 0, 1, 2]), gl.STATIC_DRAW);

wtu.shouldGenerateGLError(gl,
                          wtu.getDefault3DContextVersion() > 1 ? gl.NO_ERROR : gl.INVALID_ENUM,
                          "gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_INT, 0)");

wtu.shouldGenerateGLError(gl, gl.INVALID_ENUM,
                          "gl.drawElements(gl.TRIANGLES, 3, gl.FLOAT, 0)");
wtu.shouldGenerateGLError(gl, gl.INVALID_ENUM,
                          "gl.drawElements(gl.TRIANGLES, 3, gl.SHORT, 0)");

// Index validation
gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array([0,1,2,2000, 40802, 5887992]), gl.STATIC_DRAW);
wtu.shouldGenerateGLError(gl, gl.INVALID_OPERATION,
                          "gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_SHORT, 1)");
wtu.shouldGenerateGLError(gl, gl.NO_ERROR,
                          "gl.drawElements(gl.TRIANGLES, 2, gl.UNSIGNED_SHORT, 2)");
var indexValidationError = wtu.shouldGenerateGLError(gl, [gl.INVALID_OPERATION, gl.NO_ERROR],
                          "gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_SHORT, 2)");
wtu.shouldGenerateGLError(gl, gl.INVALID_OPERATION,
                          "gl.drawElements(gl.TRIANGLES, 3, gl.UNSIGNED_SHORT, 3)");
wtu.shouldGenerateGLError(gl, indexValidationError,
                          "gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_SHORT, 0)");
wtu.shouldGenerateGLError(gl, gl.INVALID_OPERATION,
                          "gl.drawElements(gl.TRIANGLES, 7, gl.UNSIGNED_SHORT, 0)");
wtu.shouldGenerateGLError(gl, gl.INVALID_OPERATION,
                          "gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_SHORT, 2)");

var successfullyParsed = true;
</script>
<script src="../../js/js-test-post.js"></script>

</body>
</html>
