LayoutTests/webgl/draw-framebuffer-state-sync-on-bind.html

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<meta charset="utf-8">
<link rel="stylesheet" href="resources/webgl_test_files/resources/js-test-style.css"/>
<script src="resources/webgl_test_files/js/js-test-pre.js"></script>
<script src="resources/webgl_test_files/js/webgl-test-utils.js"></script>
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<body onload="test()">
<div id="description"></div>
<div id="console"></div>
<canvas id="canvas" width="2" height="2"></canvas>
<script>
"use strict";
description("Test that draw buffer state is properly synced when framebuffer is bound to DRAW after modifications while bound to READ.");

var wtu = WebGLTestUtils;
var gl;

function test()
{
    var canvas = document.getElementById("canvas");
    gl = wtu.create3DContext(canvas, undefined, 2);

    if (!gl) {
        testFailed("WebGL2 context does not exist");
        finishTest();
        return;
    }

    testDetachWhileBoundToRead();
    testAttachWhileBoundToRead();
    testMultipleDrawBuffers();

    finishTest();
}

// Test 1: Detach texture while bound to READ, then rebind to DRAW
function testDetachWhileBoundToRead()
{
    debug("");
    debug("Test 1: Detach while bound to READ_FRAMEBUFFER, then rebind to DRAW_FRAMEBUFFER");

    var fb = gl.createFramebuffer();
    var texture = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA8, 1, 1, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);

    // Bind to DRAW, configure draw buffers, attach texture
    gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, fb);
    gl.drawBuffers([gl.COLOR_ATTACHMENT0]);
    gl.framebufferTexture2D(gl.DRAW_FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);

    // Verify initial state
    shouldBe("gl.getParameter(gl.DRAW_BUFFER0)", "gl.COLOR_ATTACHMENT0");
    shouldBe("gl.checkFramebufferStatus(gl.DRAW_FRAMEBUFFER)", "gl.FRAMEBUFFER_COMPLETE");
    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "setup should succeed");

    // Switch to READ only
    gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, null);
    gl.bindFramebuffer(gl.READ_FRAMEBUFFER, fb);

    // Detach texture while bound to READ only
    gl.framebufferTexture2D(gl.READ_FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, null, 0);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "detach while bound to READ should succeed");

    // Bind back to DRAW - draw buffer state should be synced
    gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, fb);

    // getParameter returns user-set values, not internal filtered state
    shouldBe("gl.getParameter(gl.DRAW_BUFFER0)", "gl.COLOR_ATTACHMENT0");

    // Framebuffer has no attachments, so it's incomplete
    shouldBe("gl.checkFramebufferStatus(gl.DRAW_FRAMEBUFFER)", "gl.FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT");

    // Cleanup
    gl.deleteFramebuffer(fb);
    gl.deleteTexture(texture);
    gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, null);
    gl.bindFramebuffer(gl.READ_FRAMEBUFFER, null);
}

// Test 2: Attach texture while bound to READ, then rebind to DRAW
function testAttachWhileBoundToRead()
{
    debug("");
    debug("Test 2: Attach while bound to READ_FRAMEBUFFER, then rebind to DRAW_FRAMEBUFFER");

    var fb = gl.createFramebuffer();
    var texture = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, texture);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA8, 1, 1, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);

    // Bind to DRAW, configure draw buffers (but don't attach yet)
    gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, fb);
    gl.drawBuffers([gl.COLOR_ATTACHMENT0]);

    // getParameter returns user-set values
    shouldBe("gl.getParameter(gl.DRAW_BUFFER0)", "gl.COLOR_ATTACHMENT0");

    // Framebuffer is incomplete - no attachment yet
    shouldBe("gl.checkFramebufferStatus(gl.DRAW_FRAMEBUFFER)", "gl.FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT");

    // Switch to READ only
    gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, null);
    gl.bindFramebuffer(gl.READ_FRAMEBUFFER, fb);

    // Attach texture while bound to READ only
    gl.framebufferTexture2D(gl.READ_FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "attach while bound to READ should succeed");

    // Bind back to DRAW - draw buffer state should be synced
    gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, fb);

    // Draw buffer should now be COLOR_ATTACHMENT0 (attachment exists)
    shouldBe("gl.getParameter(gl.DRAW_BUFFER0)", "gl.COLOR_ATTACHMENT0");

    // Framebuffer should be complete
    shouldBe("gl.checkFramebufferStatus(gl.DRAW_FRAMEBUFFER)", "gl.FRAMEBUFFER_COMPLETE");

    // Cleanup
    gl.deleteFramebuffer(fb);
    gl.deleteTexture(texture);
    gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, null);
    gl.bindFramebuffer(gl.READ_FRAMEBUFFER, null);
}

// Test 3: Multiple draw buffers with partial detachment
function testMultipleDrawBuffers()
{
    debug("");
    debug("Test 3: Multiple draw buffers with partial detachment while bound to READ");

    var fb = gl.createFramebuffer();
    var texture0 = gl.createTexture();
    var texture1 = gl.createTexture();

    gl.bindTexture(gl.TEXTURE_2D, texture0);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA8, 1, 1, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
    gl.bindTexture(gl.TEXTURE_2D, texture1);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA8, 1, 1, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);

    // Bind to DRAW, configure both draw buffers, attach both textures
    gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, fb);
    gl.drawBuffers([gl.COLOR_ATTACHMENT0, gl.COLOR_ATTACHMENT1]);
    gl.framebufferTexture2D(gl.DRAW_FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture0, 0);
    gl.framebufferTexture2D(gl.DRAW_FRAMEBUFFER, gl.COLOR_ATTACHMENT1, gl.TEXTURE_2D, texture1, 0);

    // Verify initial state
    shouldBe("gl.getParameter(gl.DRAW_BUFFER0)", "gl.COLOR_ATTACHMENT0");
    shouldBe("gl.getParameter(gl.DRAW_BUFFER1)", "gl.COLOR_ATTACHMENT1");
    shouldBe("gl.checkFramebufferStatus(gl.DRAW_FRAMEBUFFER)", "gl.FRAMEBUFFER_COMPLETE");

    // Switch to READ only
    gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, null);
    gl.bindFramebuffer(gl.READ_FRAMEBUFFER, fb);

    // Detach texture1 from COLOR_ATTACHMENT1 while bound to READ
    gl.framebufferTexture2D(gl.READ_FRAMEBUFFER, gl.COLOR_ATTACHMENT1, gl.TEXTURE_2D, null, 0);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "partial detach while bound to READ should succeed");

    // Bind back to DRAW - draw buffer state should be synced
    gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, fb);

    // getParameter returns user-set values
    shouldBe("gl.getParameter(gl.DRAW_BUFFER0)", "gl.COLOR_ATTACHMENT0");
    shouldBe("gl.getParameter(gl.DRAW_BUFFER1)", "gl.COLOR_ATTACHMENT1");

    // Framebuffer should be complete (internal state filters out detached COLOR_ATTACHMENT1)
    shouldBe("gl.checkFramebufferStatus(gl.DRAW_FRAMEBUFFER)", "gl.FRAMEBUFFER_COMPLETE");

    // Cleanup
    gl.deleteFramebuffer(fb);
    gl.deleteTexture(texture0);
    gl.deleteTexture(texture1);
    gl.bindFramebuffer(gl.DRAW_FRAMEBUFFER, null);
    gl.bindFramebuffer(gl.READ_FRAMEBUFFER, null);
}
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