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<title>Test clearBuffer functions with optional srcOffset argument</title>
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<script>
"use strict";
description("This tests clearBuffer* functions with optional srcOffset argument");

function verifyOnePixel(readFormat, readType, arrayType, expectedColor) {
  var buffer = new arrayType(4);
  gl.readPixels(0, 0, 1, 1, readFormat, readType, buffer);
  if (buffer[0] == expectedColor[0] &&
      buffer[1] == expectedColor[1] &&
      buffer[2] == expectedColor[2] &&
      buffer[3] == expectedColor[3]) {
    testPassed("clearBuffer sets the renderbuffer with the correct data");
  } else {
    testFailed("clearBuffer fails to work. Expected: " + expectedColor + ", got: " + buffer);
  }
}

function testClearBuffer(func, format, arrayType, readFormat, readType) {
  debug("");
  debug("Testing " + func);

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

  var renderbuffer = gl.createRenderbuffer();
  gl.bindRenderbuffer(gl.RENDERBUFFER, renderbuffer);
  gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.RENDERBUFFER, renderbuffer);
  gl.renderbufferStorage(gl.RENDERBUFFER, format, canvas.width, canvas.height);
  shouldBe('gl.checkFramebufferStatus(gl.FRAMEBUFFER)', 'gl.FRAMEBUFFER_COMPLETE');

  var srcData = new arrayType([1, 2, 3, 4, 5, 6]);
  gl[func](gl.COLOR, 0, srcData);
  wtu.glErrorShouldBe(gl, gl.NO_ERROR, "clearBuffer with no srcOffset should succeed");
  verifyOnePixel(readFormat, readType, arrayType, [1,2,3,4]);

  gl[func](gl.COLOR, 0, srcData, 0);
  wtu.glErrorShouldBe(gl, gl.NO_ERROR, "clearBuffer with srcOffset = 0 should succeed");
  verifyOnePixel(readFormat, readType, arrayType, [1,2,3,4]);

  gl[func](gl.COLOR, 0, srcData, 2);
  wtu.glErrorShouldBe(gl, gl.NO_ERROR, "clearBuffer with srcOffset = 2 should succeed");
  verifyOnePixel(readFormat, readType, arrayType, [3,4, 5, 6]);

  gl[func](gl.COLOR, 0, srcData, 4);
  wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "clearBuffer with srcOffset = 4 should fail: out of bounds");

  gl.deleteFramebuffer(fb);
  gl.deleteRenderbuffer(renderbuffer);
}

var wtu = WebGLTestUtils;
var canvas = document.getElementById("canvas");
var gl = wtu.create3DContext(canvas, undefined, 2);
if (!gl) {
  testFailed("context does not exist");
} else {
  testPassed("context exists");

  var testCases = [
    {
      func: "clearBufferiv", format: gl.RGBA32I, arrayType: Int32Array,
      readFormat: gl.RGBA_INTEGER, readType: gl.INT,
    },
    {
      func: "clearBufferuiv", format: gl.RGBA32UI, arrayType: Uint32Array,
      readFormat: gl.RGBA_INTEGER, readType: gl.UNSIGNED_INT,
    },
    {
      func: "clearBufferfv", format: gl.RGBA32F, arrayType: Float32Array,
      readFormat: gl.RGBA, readType: gl.FLOAT,
      extension: "EXT_color_buffer_float",
    },
  ];

  for (var tt = 0; tt < testCases.length; ++tt) {
    var test = testCases[tt];
    if (test.extension && !gl.getExtension(test.extension))
      continue;
    testClearBuffer(test.func, test.format, test.arrayType, test.readFormat, test.readType);
  }
}

debug("");
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "should be no error");
var successfullyParsed = true;

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