<!--
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">
<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>
<div id="description"></div>
<div id="console"></div>

<script>
"use strict";
var wtu = WebGLTestUtils;
var gl;

function checkFramebuffer(expected) {
    var actual = gl.checkFramebufferStatus(gl.FRAMEBUFFER);
    if (expected.indexOf(actual) < 0) {
        var msg = "checkFramebufferStatus expects [";
        for (var index = 0; index < expected.length; ++index) {
            msg += wtu.glEnumToString(gl, expected[index]);
            if (index + 1 < expected.length)
                msg += ", ";
        }
        msg += "], was " + wtu.glEnumToString(gl, actual);
        testFailed(msg);
    } else {
        var msg = "checkFramebufferStatus got " + wtu.glEnumToString(gl, actual) +
                  " as expected";
        testPassed(msg);
    }
}

function checkBufferBits(attachment0, attachment1) {
    if (gl.checkFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE)
        return;
    var haveDepthBuffer = attachment0 == gl.DEPTH_ATTACHMENT ||
                          attachment0 == gl.DEPTH_STENCIL_ATTACHMENT ||
                          attachment1 == gl.DEPTH_ATTACHMENT ||
                          attachment1 == gl.DEPTH_STENCIL_ATTACHMENT;
    var haveStencilBuffer = attachment0 == gl.STENCIL_ATTACHMENT ||
                            attachment0 == gl.DEPTH_STENCIL_ATTACHMENT ||
                            attachment1 == gl.STENCIL_ATTACHMENT ||
                            attachment1 == gl.DEPTH_STENCIL_ATTACHMENT;
    shouldBeTrue("gl.getParameter(gl.RED_BITS) + gl.getParameter(gl.GREEN_BITS) + " +
                 "gl.getParameter(gl.BLUE_BITS) + gl.getParameter(gl.ALPHA_BITS) >= 16");
    if (haveDepthBuffer)
        shouldBeTrue("gl.getParameter(gl.DEPTH_BITS) >= 16");
    else
        shouldBeTrue("gl.getParameter(gl.DEPTH_BITS) == 0");
    if (haveStencilBuffer)
        shouldBeTrue("gl.getParameter(gl.STENCIL_BITS) >= 8");
    else
        shouldBeTrue("gl.getParameter(gl.STENCIL_BITS) == 0");
}


function testFramebufferWebGL1RequiredCombinations() {
    debug("Checking combinations of framebuffer attachments required to be valid by WebGL 1");

    // Per discussion with the OpenGL ES working group, the following framebuffer attachment
    // combinations are required to work in all WebGL 1 implementations:
    // 1. COLOR_ATTACHMENT0 = RGBA/UNSIGNED_BYTE texture
    // 2. COLOR_ATTACHMENT0 = RGBA/UNSIGNED_BYTE texture + DEPTH_ATTACHMENT = DEPTH_COMPONENT16 renderbuffer
    // 3. COLOR_ATTACHMENT0 = RGBA/UNSIGNED_BYTE texture + DEPTH_STENCIL_ATTACHMENT = DEPTH_STENCIL renderbuffer

    var fbo = gl.createFramebuffer();
    gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);

    var width = 64;
    var height = 64;

    // 1. COLOR_ATTACHMENT0 = RGBA/UNSIGNED_BYTE texture
    var texture = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
    gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);
    checkBufferBits();

    // 2. COLOR_ATTACHMENT0 = RGBA/UNSIGNED_BYTE texture + DEPTH_ATTACHMENT = DEPTH_COMPONENT16 renderbuffer
    var renderbuffer = gl.createRenderbuffer();
    gl.bindRenderbuffer(gl.RENDERBUFFER, renderbuffer);
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, width, height);
    gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, renderbuffer);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);
    checkBufferBits(gl.DEPTH_ATTACHMENT);
    gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, null);

    // 3. COLOR_ATTACHMENT0 = RGBA/UNSIGNED_BYTE texture + DEPTH_STENCIL_ATTACHMENT = DEPTH_STENCIL renderbuffer
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_STENCIL, width, height);
    gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.RENDERBUFFER, renderbuffer);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);
    checkBufferBits(gl.DEPTH_STENCIL_ATTACHMENT);

    // Clean up
    gl.deleteRenderbuffer(renderbuffer);
    gl.deleteTexture(texture);
    gl.deleteFramebuffer(fbo);
}

function testDepthStencilAttachmentBehaviors() {
    debug("");
    debug("Checking ES3 DEPTH_STENCIL_ATTACHMENT behaviors are implemented for WebGL 2");
    // DEPTH_STENCIL_ATTACHMENT is treated as an independent attachment point in WebGL 1;
    // however, in WebGL 2, it is treated as an alias for DEPTH_ATTACHMENT + STENCIL_ATTACHMENT.
    var size = 16;

    var fbo = gl.createFramebuffer();
    gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
    var colorBuffer = gl.createRenderbuffer();
    gl.bindRenderbuffer(gl.RENDERBUFFER, colorBuffer);
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.RENDERBUFFER, colorBuffer);
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.RGBA8, size, size);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);

    var depthBuffer = gl.createRenderbuffer();
    gl.bindRenderbuffer(gl.RENDERBUFFER, depthBuffer);
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, size, size);

    var stencilBuffer = gl.createRenderbuffer();
    gl.bindRenderbuffer(gl.RENDERBUFFER, stencilBuffer);
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.STENCIL_INDEX8, size, size);

    var depthStencilBuffer = gl.createRenderbuffer();
    gl.bindRenderbuffer(gl.RENDERBUFFER, depthStencilBuffer);
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_STENCIL, size, size);

    wtu.glErrorShouldBe(gl, gl.NO_ERROR);

    debug("");
    debug("color + depth");
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, depthBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);
    checkBufferBits(gl.DEPTH_ATTACHMENT);

    debug("");
    debug("color + depth + stencil: depth != stencil");
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.RENDERBUFFER, stencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", stencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION);
    checkFramebuffer([gl.FRAMEBUFFER_UNSUPPORTED]);

    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.RENDERBUFFER, null);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION);

    debug("");
    debug("color + depth: DEPTH_STENCIL for DEPTH_ATTACHMENT");
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);
    checkBufferBits(gl.DEPTH_ATTACHMENT);

    debug("");
    debug("color + depth + stencil: DEPTH_STENCIL for DEPTH_ATTACHMENT and STENCIL_ATTACHMENT");
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.RENDERBUFFER, depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);
    checkBufferBits(gl.DEPTH_STENCIL_ATTACHMENT);

    debug("");
    debug("color + depth_stencil");
    var texture = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.DEPTH24_STENCIL8, size, size, 0, gl.DEPTH_STENCIL, gl.UNSIGNED_INT_24_8, null);
    gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.TEXTURE_2D, texture, 0);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", texture);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", texture);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", texture);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);

    gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.TEXTURE_2D, null, 0);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);

    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.RENDERBUFFER, depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);
    checkBufferBits(gl.DEPTH_STENCIL_ATTACHMENT);

    debug("");
    debug("DEPTH_STENCIL_ATTACHMENT overwrites DEPTH_ATTACHMENT/STENCIL_ATTACHMENT")
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, depthBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION);

    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.RENDERBUFFER, depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);

    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.RENDERBUFFER, null);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);
    checkBufferBits();

    debug("");
    debug("STENCIL_ATTACHMENT overwrites stencil set by DEPTH_STENCIL_ATTACHMENT")
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.RENDERBUFFER, depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);

    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.RENDERBUFFER, null);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", depthStencilBuffer);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    shouldEvaluateTo("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.DEPTH_STENCIL_ATTACHMENT, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME)", null);
    wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);
    checkBufferBits(gl.DEPTH_ATTACHMENT);
}

function testFramebufferIncompleteAttachment() {
    var fbo = gl.createFramebuffer();
    gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
    var colorBuffer = gl.createRenderbuffer();
    gl.bindRenderbuffer(gl.RENDERBUFFER, colorBuffer);
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.RENDERBUFFER, colorBuffer);
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.RGBA4, 16, 16);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);

    debug("");
    debug("Wrong storage type for type of attachment should be FRAMEBUFFER_INCOMPLETE_ATTACHMENT");
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, 16, 16);
    checkFramebuffer([gl.FRAMEBUFFER_INCOMPLETE_ATTACHMENT]);

    gl.renderbufferStorage(gl.RENDERBUFFER, gl.RGBA4, 16, 16);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);

    debug("");
    debug("0 size attachment should be FRAMEBUFFER_INCOMPLETE_ATTACHMENT");
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.RGBA4, 0, 0);
    checkFramebuffer([gl.FRAMEBUFFER_INCOMPLETE_ATTACHMENT]);

    gl.deleteRenderbuffer(colorBuffer);
    gl.deleteFramebuffer(fbo);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);
}

function testFramebufferIncompleteMissingAttachment() {
    debug("");
    debug("No attachments should be INCOMPLETE_FRAMEBUFFER_MISSING_ATTACHMENT");
    var fbo = gl.createFramebuffer();
    gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
    checkFramebuffer([gl.FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT]);

    var colorBuffer = gl.createRenderbuffer();
    gl.bindRenderbuffer(gl.RENDERBUFFER, colorBuffer);
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.RENDERBUFFER, colorBuffer);
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.RGBA4, 16, 16);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);

    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.RENDERBUFFER, null);
    checkFramebuffer([gl.FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT]);

    gl.deleteRenderbuffer(colorBuffer);
    gl.deleteFramebuffer(fbo);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);
}

function testFramebufferWithImagesOfDifferentSizes() {
    debug("");
    debug("Attachments of different sizes should NOT be allowed");

    var fbo = gl.createFramebuffer();
    gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
    var colorBuffer = gl.createRenderbuffer();
    gl.bindRenderbuffer(gl.RENDERBUFFER, colorBuffer);
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.RENDERBUFFER, colorBuffer);
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.RGBA4, 16, 16);

    var depthBuffer = gl.createRenderbuffer();
    gl.bindRenderbuffer(gl.RENDERBUFFER, depthBuffer);
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, depthBuffer);
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, 16, 16);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);
    checkFramebuffer([gl.FRAMEBUFFER_COMPLETE]);

    gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, 32, 16);
    checkFramebuffer([gl.FRAMEBUFFER_INCOMPLETE_DIMENSIONS]);
    gl.bindRenderbuffer(gl.RENDERBUFFER, colorBuffer);
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.RGBA4, 16, 32);
    checkFramebuffer([gl.FRAMEBUFFER_INCOMPLETE_DIMENSIONS]);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);

    var tex = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, tex);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 16, 16, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
    gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, tex, 0);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);
    if (gl.checkFramebufferStatus(gl.FRAMEBUFFER) == gl.FRAMEBUFFER_COMPLETE) {
        gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 32, 16, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
        checkFramebuffer([gl.FRAMEBUFFER_INCOMPLETE_DIMENSIONS]);
    }

    gl.deleteTexture(tex);
    gl.deleteRenderbuffer(depthBuffer);
    gl.deleteRenderbuffer(colorBuffer);
    gl.deleteFramebuffer(fbo);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR);
}

function testUsingIncompleteFramebuffer() {
    debug("");
    debug("Test drawing or reading from an incomplete framebuffer");
    var program = wtu.setupTexturedQuad(gl);
    var tex = gl.createTexture();
    wtu.fillTexture(gl, tex, 1, 1, [0,255,0,255]);

    var fbo = gl.createFramebuffer();
    gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
    checkFramebuffer([gl.FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT]);
    debug("");
    debug("Drawing or reading from an incomplete framebuffer should generate INVALID_FRAMEBUFFER_OPERATION");
    testRenderingAndReading();

    var colorBuffer = gl.createRenderbuffer();
    gl.bindRenderbuffer(gl.RENDERBUFFER, colorBuffer);
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.RENDERBUFFER, colorBuffer);
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.RGBA4, 0, 0);
    checkFramebuffer([gl.FRAMEBUFFER_INCOMPLETE_ATTACHMENT]);
    debug("");
    debug("Drawing or reading from an incomplete framebuffer should generate INVALID_FRAMEBUFFER_OPERATION");
    testRenderingAndReading();

    function testRenderingAndReading() {
        wtu.glErrorShouldBe(gl, gl.NO_ERROR);
        wtu.clearAndDrawUnitQuad(gl);
        wtu.glErrorShouldBe(gl, gl.INVALID_FRAMEBUFFER_OPERATION, "drawArrays with incomplete framebuffer");
        gl.readPixels(0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, new Uint8Array(4));
        wtu.glErrorShouldBe(gl, gl.INVALID_FRAMEBUFFER_OPERATION, "readPixels from incomplete framebuffer");
        // copyTexImage and copyTexSubImage can be either INVALID_FRAMEBUFFER_OPERATION because
        // the framebuffer is invalid OR INVALID_OPERATION because in the case of no attachments
        // the framebuffer is not of a compatible type.
        gl.copyTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, 0, 0, 1, 1);
        wtu.glErrorShouldBe(gl, [gl.INVALID_FRAMEBUFFER_OPERATION, gl.INVALID_OPERATION],
            "copyTexImage2D from incomplete framebuffer");
        gl.copyTexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 0, 0, 1, 1, 0);
        wtu.glErrorShouldBe(gl, [gl.INVALID_FRAMEBUFFER_OPERATION, gl.INVALID_OPERATION],
            "copyTexSubImage2D from incomplete framebuffer");
        gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
        wtu.glErrorShouldBe(gl, gl.INVALID_FRAMEBUFFER_OPERATION, "clear with incomplete framebuffer");
    }

    gl.deleteRenderbuffer(colorBuffer);
    gl.deleteFramebuffer(fbo);
    gl.deleteTexture(tex);
    gl.deleteProgram(program);
}

function testReadingFromMissingAttachment() {
    debug("");
    debug("Test drawing or reading from a framebuffer with no color image");

    var fbo = gl.createFramebuffer();
    gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
    var object_type = gl.getFramebufferAttachmentParameter(
        gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE);
    if (object_type != gl.NONE)
        testFailed("object type from empty attachment point should be NONE");
    else
        testPassed("object type from empty attachment point is NONE");
    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Query should not generate error");

    var object_name = gl.getFramebufferAttachmentParameter(
        gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_NAME);
    if (object_name)
        testFailed("object name from empty attachment point should be null");
    else
        testPassed("object name from empty attachment point is null");
    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Query should not generate error");

    var size = 16;

    // The only scenario we can verify is an attempt to read or copy
    // from a missing color attachment while the framebuffer is still
    // complete.
    var depthBuffer = gl.createRenderbuffer();
    gl.bindRenderbuffer(gl.RENDERBUFFER, depthBuffer);
    gl.framebufferRenderbuffer(
        gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, depthBuffer);
    gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, size, size);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "After depth renderbuffer setup");
    if (gl.checkFramebufferStatus(gl.FRAMEBUFFER) == gl.FRAMEBUFFER_COMPLETE) {
        // The FBO has no color attachment. ReadPixels, CopyTexImage2D,
        // and CopyTexSubImage2D should all generate INVALID_OPERATION.
        wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Before ReadPixels from missing attachment");
        gl.readPixels(0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, new Uint8Array(4));
        wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "After ReadPixels from missing attachment");

        var tex = gl.createTexture();
        gl.bindTexture(gl.TEXTURE_2D, tex);
        wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Before CopyTexImage2D from missing attachment");
        gl.copyTexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 0, 0, size, size, 0);
        wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "After CopyTexImage2D from missing attachment");

        gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, size, size, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
        wtu.glErrorShouldBe(gl, gl.NO_ERROR, "Before CopyTexSubImage2D from missing attachment");
        gl.copyTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, 0, 0, size, size);
        wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "After CopyTexSubImage2D from missing attachment");

        gl.deleteTexture(tex);
    }

    gl.deleteRenderbuffer(depthBuffer);
    gl.deleteFramebuffer(fbo);
}

description("Test framebuffer object attachment behaviors");

shouldBeNonNull("gl = wtu.create3DContext(undefined, undefined, 2)");

testFramebufferWebGL1RequiredCombinations();
testDepthStencilAttachmentBehaviors();
testFramebufferIncompleteAttachment();
testFramebufferIncompleteMissingAttachment();
testFramebufferWithImagesOfDifferentSizes();
testUsingIncompleteFramebuffer();
testReadingFromMissingAttachment();

// -

debug("");
debug("Test calling framebufferTexture2D with impossible mip levels.");

const fb = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, fb);

const tex = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, tex);

gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, tex, 1000);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "Mip level attachment impossibly high.");
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, tex, 10);
wtu.glErrorShouldBe(gl, 0, "Mip level attachment within acceptable range.");

// Firefox bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1636517 :
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, null, 1000);
wtu.glErrorShouldBe(gl, 0, "Mip level detachment can be impossibly high.");
shouldBe("gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE)", "0");

// -

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

<script src="../../js/js-test-post.js"></script>
</body>
</html>
