<!--
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>vertexAttribIPointer offsets tests</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">
There is supposed to be an example drawing here, but it's not important.
</canvas>
<div id="description"></div>
<div id="console"></div>
<script id="vshader" type="x-shader/x-vertex">#version 300 es
layout(location=0) in ivec4 aPosition;
layout(location=1) in vec4 aColor;
out vec4 vColor;
void main()
{
    gl_Position = vec4(aPosition);
    vColor = aColor;
}
</script>

<script id="vshader_unsigned" type="x-shader/x-vertex">#version 300 es
layout(location=0) in uvec4 aPosition;
layout(location=1) in vec4 aColor;
out vec4 vColor;
void main()
{
    gl_Position = vec4(aPosition);
    vColor = aColor;
}

</script>
<script id="fshader" type="x-shader/x-fragment">#version 300 es
precision mediump float;
in vec4 vColor;
layout(location=0) out vec4 oColor;
void main()
{
    oColor = vColor;
}
</script>

<script>
"use strict";
function init()
{
    description("test vertexAttribIPointer offsets work");

    var wtu = WebGLTestUtils;
    var gl = wtu.create3DContext("example", undefined, 2);
    var program = wtu.setupProgram(gl, ["vshader", "fshader"]);
    var program_unsigned = wtu.setupProgram(gl, ["vshader_unsigned", "fshader"]);

    var tests = [
      { data: new Int32Array([ 0, 1, 0, 1, 0, 0, 0, 0, 0 ]),
        type: gl.INT,
        componentSize: 4,
      },
      { data: new Uint32Array([ 0, 1, 0, 1, 0, 0, 0, 0, 0 ]),
        type: gl.UNSIGNED_INT,
        componentSize: 4,
      },
      { data: new Uint16Array([ 0, 32767, 0, 32767, 0, 0, 0, 0, 0 ]),
        type: gl.SHORT,
        componentSize: 2,
      },
      { data: new Uint16Array([ 0, 65535, 0, 65535, 0, 0, 0, 0, 0 ]),
        type: gl.UNSIGNED_SHORT,
        componentSize: 2,
      },
      { data: new Uint8Array([ 0, 127, 0, 127, 0, 0, 0, 0, 0 ]),
        type: gl.BYTE,
        componentSize: 1,
      },
      { data: new Uint8Array([ 0, 1, 0, 1, 0, 0, 0, 0, 0 ]),
        type: gl.UNSIGNED_BYTE,
        componentSize: 1,
      }
    ];

    var vertexObject = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER, vertexObject);
    gl.bufferData(gl.ARRAY_BUFFER, 1024, gl.STATIC_DRAW);
    gl.enableVertexAttribArray(0);

    var kNumVerts = 3;
    var kNumComponents = 3;

    var count = 0;
    for (var tt = 0; tt < tests.length; ++tt) {
        var test = tests[tt];
        for (var oo = 0; oo < 3; ++oo) {
            for (var ss = 0; ss < 3; ++ss) {
                var offset = (oo + 1) * test.componentSize;
                var color = (count % 2) ? [1, 0, 0, 1] : [0, 1, 0, 1];
                var stride = test.componentSize * kNumComponents + test.componentSize * ss;
                debug("");
                debug("check with " + wtu.glEnumToString(gl, test.type) + " at offset: " + offset + " with stride:" + stride);
                if (test.type == gl.INT || test.type == gl.SHORT || test.type == gl.BYTE) {
                    gl.useProgram(program);
                } else {
                    gl.useProgram(program_unsigned);
                }
                gl.vertexAttrib4fv(1, color);
                var data = new Uint8Array(test.componentSize * kNumVerts * kNumComponents + stride * (kNumVerts - 1));
                var view = new Uint8Array(test.data.buffer);
                var size = test.componentSize * kNumComponents;
                for (var jj = 0; jj < kNumVerts; ++jj) {
                    var off1 = jj * size;
                    var off2 = jj * stride;
                    for (var zz = 0; zz < size; ++zz) {
                        data[off2 + zz] = view[off1 + zz];
                    }
                }
                gl.bufferSubData(gl.ARRAY_BUFFER, offset, data);
                gl.vertexAttribIPointer(0, 3, test.type, stride, offset);
                gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
                gl.drawArrays(gl.TRIANGLES, 0, 3);

                var buf = new Uint8Array(50 * 50 * 4);
                gl.readPixels(0, 0, 50, 50, gl.RGBA, gl.UNSIGNED_BYTE, buf);

                var black = [0, 0, 0, 0];
                var other = [color[0] * 255, color[1] * 255, color[2] * 255, color[3] * 255];
                var otherMsg = "should be " + ((count % 2) ? "red" : "green")
                wtu.checkCanvasRect(gl, 0, 0, 1, 1, black, "should be black", 0);
                wtu.checkCanvasRect(gl, 0, 49, 1, 1, black, "should be black", 0);
                wtu.checkCanvasRect(gl, 26, 40, 1, 1, other, otherMsg, 0);
                wtu.checkCanvasRect(gl, 26, 27, 1, 1, other, otherMsg, 0);
                wtu.checkCanvasRect(gl, 40, 27, 1, 1, other, otherMsg, 0);
                ++count;
            }
        }
    }
}

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

</body>
</html>
