﻿<!--
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.
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<html>
<head>
<meta charset="utf-8">
<title>WebGL EXT_shader_texture_lod Conformance Tests</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>
<div id="description"></div>
<canvas id="canvas" style="width: 256px; height: 256px;"> </canvas>
<canvas id="canvas2" style="width: 256px; height: 256px;"> </canvas>
<div id="console"></div>
<!-- Shaders for testing texture LOD functions -->

<!-- Shader omitting the required #extension pragma -->
<script id="missingPragmaFragmentShader" type="x-shader/x-fragment">
precision mediump float;
varying vec2 texCoord0v;
uniform float lod;
uniform sampler2D tex;
void main() {
    vec4 color = texture2DLodEXT(tex, texCoord0v, lod);
    gl_FragColor = color;
}
</script>

<!-- Shader to test macro definition -->
<script id="macroFragmentShader" type="x-shader/x-fragment">
precision mediump float;
void main() {
#ifdef GL_EXT_shader_texture_lod
    gl_FragColor = vec4(0.0, 0.0, 0.0, 0.0);
#else
    // Error expected
    #error no GL_EXT_shader_texture_lod;
#endif
}
</script>

<!-- Shader with required #extension pragma -->
<script id="testFragmentShader" type="x-shader/x-fragment">
#extension GL_EXT_shader_texture_lod : enable
precision mediump float;
varying vec2 texCoord0v;
uniform float lod;
uniform sampler2D tex;
void main() {
    vec4 color = texture2DLodEXT(tex, texCoord0v, lod);
    gl_FragColor = color;
}
</script>

<!-- Shaders to link with test fragment shaders -->
<script id="goodVertexShader" type="x-shader/x-vertex">
attribute vec4 vPosition;
attribute vec2 texCoord0;
varying vec2 texCoord0v;
void main() {
    texCoord0v = texCoord0;
    gl_Position = vPosition;
}
</script>

<!-- Shaders to test output -->
<script id="outputVertexShader" type="x-shader/x-vertex">
attribute vec4 vPosition;
attribute vec2 texCoord0;
varying vec2 texCoord0v;
void main() {
    texCoord0v = texCoord0;
    gl_Position = vPosition;
}
</script>
<script id="outputFragmentShader" type="x-shader/x-fragment">
#extension GL_EXT_shader_texture_lod : require
precision mediump float;
varying vec2 texCoord0v;
uniform float lod;
uniform sampler2D tex;
void main() {
    vec4 color = texture2DLodEXT(tex, texCoord0v, lod);
    gl_FragColor = color;
}
</script>

<script>
description("This test verifies the functionality of the EXT_shader_texture_lod extension, if it is available.");

debug("");

var wtu = WebGLTestUtils;
var canvas = document.getElementById("canvas");
var gl = wtu.create3DContext(canvas);
var ext = null;

// Run all tests once.
runAllTests();

// Run all tests against with a new context to test for any cache issues.
debug("");
debug("Testing new context to catch cache errors");
var canvas2 = document.getElementById("canvas2");
gl = wtu.create3DContext(canvas2);
ext = null;
runAllTests();

function runAllTests() {
    if (!gl) {
        testFailed("WebGL context does not exist");
    } else {
        testPassed("WebGL context exists");

        // Run tests with extension disabled
        runShaderTests(false);

        // Query the extension and store globally so shouldBe can access it
        ext = gl.getExtension("EXT_shader_texture_lod");
        if (!ext) {
            testPassed("No EXT_shader_texture_lod support -- this is legal");

            runSupportedTest(false);
        } else {
            testPassed("Successfully enabled EXT_shader_texture_lod extension");

            runSupportedTest(true);

            runShaderTests(true);
            runOutputTests();
            runUniqueObjectTest();
            runReferenceCycleTest();

            // Run deferred link tests.
            runDeferredLinkTests();
        }
    }

}

function runSupportedTest(extensionEnabled) {
    var supported = gl.getSupportedExtensions();
    if (supported.indexOf("EXT_shader_texture_lod") >= 0) {
        if (extensionEnabled) {
            testPassed("EXT_shader_texture_lod listed as supported and getExtension succeeded");
        } else {
            testFailed("EXT_shader_texture_lod listed as supported but getExtension failed");
        }
    } else {
        if (extensionEnabled) {
            testFailed("EXT_shader_texture_lod not listed as supported but getExtension succeeded");
        } else {
            testPassed("EXT_shader_texture_lod not listed as supported and getExtension failed -- this is legal");
        }
    }
}

function runShaderTests(extensionEnabled) {
    debug("");
    debug("Testing various shader compiles with extension " + (extensionEnabled ? "enabled" : "disabled"));

    // Expect the macro shader to succeed ONLY if enabled
    var macroFragmentProgram = wtu.loadProgramFromScriptExpectError(gl, "goodVertexShader", "macroFragmentShader");
    if (extensionEnabled) {
        if (macroFragmentProgram) {
            // Expected result
            testPassed("GL_EXT_shader_texture_lod defined in shaders when extension is enabled");
        } else {
            testFailed("GL_EXT_shader_texture_lod not defined in shaders when extension is enabled");
        }
    } else {
        if (macroFragmentProgram) {
            testFailed("GL_EXT_shader_texture_lod defined in shaders when extension is disabled");
        } else {
            testPassed("GL_EXT_shader_texture_lod not defined in shaders when extension disabled");
        }
    }

    // Always expect the shader missing the #pragma to fail (whether enabled or not)
    var missingPragmaFragmentProgram = wtu.loadProgramFromScriptExpectError(gl, "goodVertexShader", "missingPragmaFragmentShader");
    if (missingPragmaFragmentProgram) {
        testFailed("Shader built-ins allowed without #extension pragma");
    } else {
        testPassed("Shader built-ins disallowed without #extension pragma");
    }

    // Try to compile a shader using the built-ins that should only succeed if enabled
    var testFragmentProgram = wtu.loadProgramFromScriptExpectError(gl, "goodVertexShader", "testFragmentShader");
    if (extensionEnabled) {
        if (testFragmentProgram) {
            testPassed("Shader built-ins compiled successfully when extension enabled");
        } else {
            testFailed("Shader built-ins failed to compile when extension enabled");
        }
    } else {
        if (testFragmentProgram) {
            testFailed("Shader built-ins compiled successfully when extension disabled");
        } else {
            testPassed("Shader built-ins failed to compile when extension disabled");
        }
    }
}

function runOutputTests() {
    debug("");
    debug("Testing various draws for valid built-in function behavior");
    gl.viewport(0, 0, canvas.width, canvas.height);

    var program = wtu.setupProgram(gl, ["outputVertexShader", "outputFragmentShader"], ['vPosition', 'texCoord0'], [0, 1]);
    var quadParameters = wtu.setupUnitQuad(gl, 0, 1);

    var colors = [
        {name: 'red', color:[255, 0, 0, 255]},
        {name: 'green', color:[0, 255, 0, 255]},
        {name: 'blue', color:[0, 0, 255, 255]},
        {name: 'yellow', color:[255, 255, 0, 255]},
        {name: 'magenta', color:[255, 0, 255, 255]},
        {name: 'cyan', color:[0, 255, 255, 255]},
        {name: 'pink', color:[255, 128, 128, 255]},
        {name: 'gray', color:[128, 128, 128, 255]},
        {name: 'light green', color:[128, 255, 128, 255]},
    ];

    var tex = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, tex);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST_MIPMAP_LINEAR);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT);

    for (var ii = 0; ii < colors.length; ++ii) {
        var color = colors[ii];
        var size = Math.pow(2, colors.length - ii - 1);
        wtu.fillTexture(gl, tex, size, size, color.color, ii);
    }

    var loc = gl.getUniformLocation(program, "lod");

    for (var ii = 0; ii < colors.length; ++ii) {
        gl.uniform1f(loc, ii);
        var color = colors[ii];
        wtu.drawUnitQuad(gl);
        wtu.checkCanvas(
            gl, color.color,
            "256x256 texture drawn to 256x256 dest with lod = " + ii +
            " should be " + color.name);
    }

    wtu.glErrorShouldBe(gl, gl.NO_ERROR);
}

function runUniqueObjectTest()
{
    debug("");
    debug("Testing that getExtension() returns the same object each time");
    ext = null;
    gl.getExtension("EXT_shader_texture_lod").myProperty = 2;
    webglHarnessCollectGarbage();
    shouldBe('gl.getExtension("EXT_shader_texture_lod").myProperty', '2');
}

function runReferenceCycleTest()
{
    // create some reference cycles. The goal is to see if they cause leaks. The point is that
    // some browser test runners have instrumentation to detect leaked refcounted objects.
    debug("");
    debug("Testing reference cycles between context and extension objects");
    var ext = gl.getExtension("EXT_shader_texture_lod");

    // create cycle between extension and context, since the context has to hold a reference to the extension
    ext.context = gl;

    // create a self-cycle on the extension object
    ext.ext = ext;
}

function runDeferredLinkTests() {
    debug("");
    debug("Testing deferred shader compilation tests.");

    // Test for compilation failures that are caused by missing extensions
    // do not succeed if extensions are enabled during linking. This would
    // only happen for deferred shader compilations.

    // First test if link succeeds with extension enabled.
    var glEnabled = wtu.create3DContext();
    var extEnabled = glEnabled.getExtension("EXT_shader_texture_lod");
    if (!extEnabled) {
        testFailed("Deferred link test expects the extension to be supported");
    }

    var vertexShader = wtu.loadShaderFromScript(glEnabled, "goodVertexShader");
    var fragmentShader = wtu.loadShaderFromScript(glEnabled, "macroFragmentShader");

    if (!vertexShader || !fragmentShader) {
        testFailed("Could not create good shaders.");
        return;
    }

    var program = wtu.setupProgram(glEnabled, [vertexShader, fragmentShader]);

    if (!program) {
        testFailed("Compilation with extension enabled failed.");
        return;
    }

    // Create new context to test link failure without extension enabled.
    var glDeferred = wtu.create3DContext();

    var vertexShader = wtu.loadShaderFromScript(glDeferred, "goodVertexShader", glDeferred.VERTEX_SHADER, undefined, undefined, true);
    var fragmentShader = wtu.loadShaderFromScript(glDeferred, "macroFragmentShader", glDeferred.FRAGMENT_SHADER, undefined, undefined, true);

    if (vertexShader == null || fragmentShader == null) {
        testFailed("Could not create shaders.");
        return;
    }

    // Shader compilations should have failed due to extensions not enabled.
    glDeferred.getExtension("EXT_shader_texture_lod");
    var program = wtu.setupProgram(glDeferred, [vertexShader, fragmentShader]);
    if (program) {
        testFailed("Compilation with extension disabled then linking with extension enabled should have failed.");
        return;
    }

    testPassed("Compilation with extension disabled then linking with extension enabled.");
}

debug("");
successfullyParsed = true;
</script>
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