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<title>WebGL WEBGL_compressed_texture_s3tc and EXT_texture_compression_rgtc Conformance Tests</title>
<style>
img {
border: 1px solid black;
margin-right: 1em;
}
.testimages br {
clear: both;
}
.testimages > div {
float: left;
margin: 1em;
}
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<canvas id="canvas" width="8" height="8" style="width: 8px; height: 8px;"></canvas>
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<script>
"use strict";
description("This test verifies the functionality of the WEBGL_compressed_texture_s3tc extension, if it is available. It also tests the related formats from the EXT_texture_compression_rgtc extension.");
debug("");
// Acceptable interpolation error depends on endpoints:
// 1.0 / 255.0 + 0.03 * max(abs(endpoint0 - endpoint1), abs(endpoint0_p - endpoint1_p))
// For simplicity, assume the worst case (e0 is 0.0, e1 is 1.0). After conversion to unorm8, it is 9.
const DEFAULT_COLOR_ERROR = 9;
/*
BC1 (DXT1) block
e0 = [ 0, 255, 0]
e1 = [255, 0, 0]
e0 < e1, so it uses 3-color mode
local palette
0: [ 0, 255, 0, 255]
1: [255, 0, 0, 255]
2: [128, 128, 0, 255]
3: [ 0, 0, 0, 255] // for BC1 RGB
3: [ 0, 0, 0, 0] // for BC1 RGBA
selectors
3 2 1 0
2 2 1 0
1 1 1 0
0 0 0 0
Extending this block with opaque alpha and uploading as BC2 or BC3
will generate wrong colors because BC2 and BC3 do not have 3-color mode.
*/
var img_4x4_rgba_dxt1 = new Uint8Array([
0xE0, 0x07, 0x00, 0xF8, 0x1B, 0x1A, 0x15, 0x00
]);
/*
BC2 (DXT3) block
Quantized alpha values
0 1 2 3
4 5 6 7
8 9 A B
C D E F
RGB block
e0 = [255, 0, 0]
e1 = [ 0, 255, 0]
BC2 has only 4-color mode
local palette
0: [255, 0, 0]
1: [ 0, 255, 0]
2: [170, 85, 0]
3: [ 85, 170, 0]
selectors
0 1 2 3
1 1 2 3
2 2 2 3
3 3 3 3
*/
var img_4x4_rgba_dxt3 = new Uint8Array([
0x10, 0x32, 0x54, 0x76, 0x98, 0xBA, 0xDC, 0xFE,
0x00, 0xF8, 0xE0, 0x07, 0xE4, 0xE5, 0xEA, 0xFF
]);
/*
BC3 (DXT5) block
Alpha block (aka DXT5A)
e0 = 255
e1 = 0
e0 > e1, so using 6 intermediate points
local palette
255, 0, 219, 182, 146, 109, 73, 36
selectors
0 1 2 3
1 2 3 4
2 3 4 5
3 4 5 6
RGB block
e0 = [255, 0, 0]
e1 = [ 0, 255, 0]
BC3 has only 4-color mode
local palette
0: [255, 0, 0]
1: [ 0, 255, 0]
2: [170, 85, 0]
3: [ 85, 170, 0]
selectors
3 2 1 0
3 2 1 1
3 2 2 2
3 3 3 3
*/
var img_4x4_rgba_dxt5 = new Uint8Array([
0xFF, 0x00, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
0x00, 0xF8, 0xE0, 0x07, 0x1B, 0x5B, 0xAB, 0xFF
]);
// BC4 - just the alpha block from BC3 above, interpreted as the red channel.
// See http://www.reedbeta.com/blog/understanding-bcn-texture-compression-formats/#bc4
// for format details.
var img_4x4_r_bc4 = new Uint8Array([
0xFF, 0x00, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
]);
// BC5 - Two BC3 alpha blocks, interpreted as the red and green channels.
var img_4x4_rg_bc5 = new Uint8Array([
0xFF, 0x00, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
0x00, 0xFF, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
]);
// Signed BC4 - change endpoints to use full -1 to 1 range.
var img_4x4_signed_r_bc4 = new Uint8Array([
0x7F, 0x80, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
]);
// Signed BC5 - Two BC3 alpha blocks, interpreted as the red and green channels.
var img_4x4_signed_rg_bc5 = new Uint8Array([
0x7F, 0x80, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
0x80, 0x7F, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
]);
/*
8x8 block endpoints use half-intensity values (appear darker than 4x4)
*/
var img_8x8_rgba_dxt1 = new Uint8Array([
0xe0,0x03,0x00,0x78,0x13,0x10,0x15,0x00,
0x0f,0x00,0xe0,0x7b,0x11,0x10,0x15,0x00,
0xe0,0x03,0x0f,0x78,0x44,0x45,0x40,0x55,
0x0f,0x00,0xef,0x03,0x44,0x45,0x40,0x55
]);
var img_8x8_rgba_dxt3 = new Uint8Array([
0xf6,0xff,0xf6,0xff,0xff,0xff,0xff,0xff,0x00,0x78,0xe0,0x03,0x44,0x45,0x40,0x55,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xe0,0x7b,0x0f,0x00,0x44,0x45,0x40,0x55,
0xff,0xff,0xff,0xff,0xf6,0xff,0xf6,0xff,0x0f,0x78,0xe0,0x03,0x11,0x10,0x15,0x00,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xef,0x03,0x0f,0x00,0x11,0x10,0x15,0x00
]);
var img_8x8_rgba_dxt5 = new Uint8Array([
0xff,0x69,0x01,0x10,0x00,0x00,0x00,0x00,0x00,0x78,0xe0,0x03,0x44,0x45,0x40,0x55,
0xff,0xff,0x00,0x00,0x00,0x00,0x00,0x00,0xe0,0x7b,0x0f,0x00,0x44,0x45,0x40,0x55,
0xff,0x69,0x00,0x00,0x00,0x01,0x10,0x00,0x0f,0x78,0xe0,0x03,0x11,0x10,0x15,0x00,
0xff,0xff,0x00,0x00,0x00,0x00,0x00,0x00,0xef,0x03,0xef,0x00,0x11,0x10,0x15,0x00
]);
var img_8x8_r_bc4 = new Uint8Array([
0x7F, 0x00, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
0x7F, 0x00, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
0x7F, 0x00, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
0x7F, 0x00, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
]);
var img_8x8_rg_bc5 = new Uint8Array([
0x7F, 0x00, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6, 0x00, 0x7F, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
0x7F, 0x00, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6, 0x00, 0x7F, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
0x7F, 0x00, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6, 0x00, 0x7F, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
0x7F, 0x00, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6, 0x00, 0x7F, 0x88, 0x16, 0x8D, 0x1A, 0x3B, 0xD6,
]);
var wtu = WebGLTestUtils;
var ctu = CompressedTextureUtils;
var contextVersion = wtu.getDefault3DContextVersion();
var canvas = document.getElementById("canvas");
var gl = wtu.create3DContext(canvas, {antialias: false});
var program = wtu.setupTexturedQuad(gl);
var ext = null;
var ext_rgtc = {};
var vao = null;
var validFormats = {
COMPRESSED_RGB_S3TC_DXT1_EXT : 0x83F0,
COMPRESSED_RGBA_S3TC_DXT1_EXT : 0x83F1,
COMPRESSED_RGBA_S3TC_DXT3_EXT : 0x83F2,
COMPRESSED_RGBA_S3TC_DXT5_EXT : 0x83F3,
};
var name;
var supportedFormats;
if (!gl) {
testFailed("WebGL context does not exist");
} else {
testPassed("WebGL context exists");
// Run tests with extension disabled
ctu.testCompressedFormatsUnavailableWhenExtensionDisabled(gl, validFormats, expectedByteLength, 4);
// Query the extension and store globally so shouldBe can access it
ext = wtu.getExtensionWithKnownPrefixes(gl, "WEBGL_compressed_texture_s3tc");
if (!ext) {
testPassed("No WEBGL_compressed_texture_s3tc support -- this is legal");
wtu.runExtensionSupportedTest(gl, "WEBGL_compressed_texture_s3tc", false);
} else {
testPassed("Successfully enabled WEBGL_compressed_texture_s3tc extension");
wtu.runExtensionSupportedTest(gl, "WEBGL_compressed_texture_s3tc", true);
runTestExtension();
}
ext_rgtc = wtu.getExtensionWithKnownPrefixes(gl, "EXT_texture_compression_rgtc");
if (ext_rgtc) {
ext = ext || {};
// Make ctu.formatToString work for rgtc enums.
for (const name in ext_rgtc)
ext[name] = ext_rgtc[name];
runTestRGTC();
}
}
function expectedByteLength(width, height, format) {
if (format == validFormats.COMPRESSED_RGBA_S3TC_DXT3_EXT || format == validFormats.COMPRESSED_RGBA_S3TC_DXT5_EXT) {
return Math.floor((width + 3) / 4) * Math.floor((height + 3) / 4) * 16;
}
return Math.floor((width + 3) / 4) * Math.floor((height + 3) / 4) * 8;
}
function getBlockDimensions(format) {
return {width: 4, height: 4};
}
function runTestExtension() {
debug("");
debug("Testing WEBGL_compressed_texture_s3tc");
// Test that enum values are listed correctly in supported formats and in the extension object.
ctu.testCompressedFormatsListed(gl, validFormats);
ctu.testCorrectEnumValuesInExt(ext, validFormats);
// Test that texture upload buffer size is validated correctly.
ctu.testFormatRestrictionsOnBufferSize(gl, validFormats, expectedByteLength, getBlockDimensions);
// Test each format
testDXT1_RGB();
testDXT1_RGBA();
testDXT3_RGBA();
testDXT5_RGBA();
// Test compressed PBOs with a single format
if (contextVersion >= 2) {
testDXT5_RGBA_PBO();
}
// Test TexImage validation on level dimensions combinations.
debug("");
debug("When level equals 0, width and height must be a multiple of 4.");
debug("When level is larger than 0, this constraint doesn't apply.");
ctu.testTexImageLevelDimensions(gl, ext, validFormats, expectedByteLength, getBlockDimensions,
[
{ level: 0, width: 4, height: 3, expectation: gl.INVALID_OPERATION, message: "0: 4x3" },
{ level: 0, width: 3, height: 4, expectation: gl.INVALID_OPERATION, message: "0: 3x4" },
{ level: 0, width: 2, height: 2, expectation: gl.INVALID_OPERATION, message: "0: 2x2" },
{ level: 0, width: 4, height: 4, expectation: gl.NO_ERROR, message: "0: 4x4" },
{ level: 1, width: 2, height: 2, expectation: gl.NO_ERROR, message: "1: 2x2" },
{ level: 2, width: 1, height: 1, expectation: gl.NO_ERROR, message: "2: 1x1" },
]);
ctu.testTexSubImageDimensions(gl, ext, validFormats, expectedByteLength, getBlockDimensions, 16, 16,
[
{ xoffset: 0, yoffset: 0, width: 4, height: 3,
expectation: gl.INVALID_OPERATION, message: "height is not a multiple of 4" },
{ xoffset: 0, yoffset: 0, width: 3, height: 4,
expectation: gl.INVALID_OPERATION, message: "width is not a multiple of 4" },
{ xoffset: 1, yoffset: 0, width: 4, height: 4,
expectation: gl.INVALID_OPERATION, message: "xoffset is not a multiple of 4" },
{ xoffset: 0, yoffset: 1, width: 4, height: 4,
expectation: gl.INVALID_OPERATION, message: "yoffset is not a multiple of 4" },
{ xoffset: 12, yoffset: 12, width: 4, height: 4,
expectation: gl.NO_ERROR, message: "is valid" },
]);
if (contextVersion >= 2) {
debug("");
debug("Testing NPOT textures");
ctu.testTexImageLevelDimensions(gl, ext, validFormats, expectedByteLength, getBlockDimensions,
[
{ level: 0, width: 0, height: 0, expectation: gl.NO_ERROR, message: "0: 0x0 is valid" },
{ level: 0, width: 1, height: 1, expectation: gl.INVALID_OPERATION, message: "0: 1x1 is invalid" },
{ level: 0, width: 2, height: 2, expectation: gl.INVALID_OPERATION, message: "0: 2x2 is invalid" },
{ level: 0, width: 3, height: 3, expectation: gl.INVALID_OPERATION, message: "0: 3x3 is invalid" },
{ level: 0, width: 10, height: 10, expectation: gl.INVALID_OPERATION, message: "0: 10x10 is invalid" },
{ level: 0, width: 11, height: 11, expectation: gl.INVALID_OPERATION, message: "0: 11x11 is invalid" },
{ level: 0, width: 11, height: 12, expectation: gl.INVALID_OPERATION, message: "0: 11x12 is invalid" },
{ level: 0, width: 12, height: 11, expectation: gl.INVALID_OPERATION, message: "0: 12x11 is invalid" },
{ level: 0, width: 12, height: 12, expectation: gl.NO_ERROR, message: "0: 12x12 is valid" },
{ level: 1, width: 0, height: 0, expectation: gl.NO_ERROR, message: "1: 0x0, is valid" },
{ level: 1, width: 3, height: 3, expectation: gl.INVALID_OPERATION, message: "1: 3x3, is invalid" },
{ level: 1, width: 5, height: 5, expectation: gl.INVALID_OPERATION, message: "1: 5x5, is invalid" },
{ level: 1, width: 5, height: 6, expectation: gl.INVALID_OPERATION, message: "1: 5x6, is invalid" },
{ level: 1, width: 6, height: 5, expectation: gl.INVALID_OPERATION, message: "1: 6x5, is invalid" },
{ level: 1, width: 6, height: 6, expectation: gl.NO_ERROR, message: "1: 6x6, is valid" },
{ level: 2, width: 0, height: 0, expectation: gl.NO_ERROR, message: "2: 0x0, is valid" },
{ level: 2, width: 3, height: 3, expectation: gl.NO_ERROR, message: "2: 3x3, is valid" },
{ level: 3, width: 1, height: 3, expectation: gl.NO_ERROR, message: "3: 1x3, is valid" },
{ level: 3, width: 1, height: 1, expectation: gl.NO_ERROR, message: "3: 1x1, is valid" },
]);
debug("");
debug("Testing partial updates");
ctu.testTexSubImageDimensions(gl, ext, validFormats, expectedByteLength, getBlockDimensions, 12, 12,
[
{ xoffset: 0, yoffset: 0, width: 4, height: 3,
expectation: gl.INVALID_OPERATION, message: "height is not a multiple of 4" },
{ xoffset: 0, yoffset: 0, width: 3, height: 4,
expectation: gl.INVALID_OPERATION, message: "width is not a multiple of 4" },
{ xoffset: 1, yoffset: 0, width: 4, height: 4,
expectation: gl.INVALID_OPERATION, message: "xoffset is not a multiple of 4" },
{ xoffset: 0, yoffset: 1, width: 4, height: 4,
expectation: gl.INVALID_OPERATION, message: "yoffset is not a multiple of 4" },
{ xoffset: 8, yoffset: 8, width: 4, height: 4,
expectation: gl.NO_ERROR, message: "is valid" },
]);
debug("");
debug("Testing immutable NPOT textures");
ctu.testTexStorageLevelDimensions(gl, ext, validFormats, expectedByteLength, getBlockDimensions,
[
{ width: 12, height: 12, expectation: gl.NO_ERROR, message: "0: 12x12 is valid" },
{ width: 6, height: 6, expectation: gl.NO_ERROR, message: "1: 6x6, is valid" },
{ width: 3, height: 3, expectation: gl.NO_ERROR, message: "2: 3x3, is valid" },
{ width: 1, height: 1, expectation: gl.NO_ERROR, message: "3: 1x1, is valid" },
]);
}
}
function runTestRGTC() {
var tests = [
{ width: 4,
height: 4,
channels: 1,
data: img_4x4_r_bc4,
format: ext_rgtc.COMPRESSED_RED_RGTC1_EXT,
hasAlpha: false,
},
{ width: 4,
height: 4,
channels: 1,
data: img_4x4_signed_r_bc4,
format: ext_rgtc.COMPRESSED_SIGNED_RED_RGTC1_EXT,
hasAlpha: false,
},
{ width: 4,
height: 4,
channels: 2,
data: img_4x4_rg_bc5,
format: ext_rgtc.COMPRESSED_RED_GREEN_RGTC2_EXT,
hasAlpha: false,
},
{ width: 4,
height: 4,
channels: 2,
data: img_4x4_signed_rg_bc5,
format: ext_rgtc.COMPRESSED_SIGNED_RED_GREEN_RGTC2_EXT,
hasAlpha: false,
error: 18, // Signed, so twice the normal error.
// Experimentally needed by e.g. RTX 3070.
},
{ width: 8,
height: 8,
channels: 2,
data: img_8x8_r_bc4,
format: ext_rgtc.COMPRESSED_RED_RGTC1_EXT,
hasAlpha: false,
subX0: 0,
subY0: 0,
subWidth: 4,
subHeight: 4,
subData: img_4x4_r_bc4,
},
{ width: 8,
height: 8,
channels: 2,
data: img_8x8_rg_bc5,
format: ext_rgtc.COMPRESSED_RED_GREEN_RGTC2_EXT,
hasAlpha: false,
subX0: 0,
subY0: 0,
subWidth: 4,
subHeight: 4,
subData: img_4x4_rg_bc5,
},
];
testDXTTextures(tests);
}
function testDXT1_RGB() {
var tests = [
{ width: 4,
height: 4,
channels: 3,
data: img_4x4_rgba_dxt1,
format: ext.COMPRESSED_RGB_S3TC_DXT1_EXT,
hasAlpha: false,
},
{ width: 8,
height: 8,
channels: 3,
data: img_8x8_rgba_dxt1,
format: ext.COMPRESSED_RGB_S3TC_DXT1_EXT,
hasAlpha: false,
subX0: 0,
subY0: 0,
subWidth: 4,
subHeight: 4,
subData: img_4x4_rgba_dxt1
}
];
testDXTTextures(tests);
}
function testDXT1_RGBA() {
var tests = [
{ width: 4,
height: 4,
channels: 4,
data: img_4x4_rgba_dxt1,
format: ext.COMPRESSED_RGBA_S3TC_DXT1_EXT,
// This is a special case -- the texture is still opaque
// though it's RGBA.
hasAlpha: false,
},
{ width: 8,
height: 8,
channels: 4,
data: img_8x8_rgba_dxt1,
format: ext.COMPRESSED_RGBA_S3TC_DXT1_EXT,
// This is a special case -- the texture is still opaque
// though it's RGBA.
hasAlpha: false,
}
];
testDXTTextures(tests);
}
function testDXT3_RGBA() {
var tests = [
{ width: 4,
height: 4,
channels: 4,
data: img_4x4_rgba_dxt3,
format: ext.COMPRESSED_RGBA_S3TC_DXT3_EXT,
hasAlpha: true,
},
{ width: 8,
height: 8,
channels: 4,
data: img_8x8_rgba_dxt3,
format: ext.COMPRESSED_RGBA_S3TC_DXT3_EXT,
hasAlpha: true,
subX0: 0,
subY0: 0,
subWidth: 4,
subHeight: 4,
subData: img_4x4_rgba_dxt3
}
];
testDXTTextures(tests);
}
function testDXT5_RGBA() {
var tests = [
{ width: 4,
height: 4,
channels: 4,
data: img_4x4_rgba_dxt5,
format: ext.COMPRESSED_RGBA_S3TC_DXT5_EXT,
hasAlpha: true,
},
{ width: 8,
height: 8,
channels: 4,
data: img_8x8_rgba_dxt5,
format: ext.COMPRESSED_RGBA_S3TC_DXT5_EXT,
hasAlpha: true,
subX0: 0,
subY0: 0,
subWidth: 4,
subHeight: 4,
subData: img_4x4_rgba_dxt5
}
];
testDXTTextures(tests);
}
function testDXTTextures(tests) {
debug("<hr/>");
for (var ii = 0; ii < tests.length; ++ii) {
testDXTTexture(tests[ii], false);
if (contextVersion >= 2) {
debug("<br/>");
testDXTTexture(tests[ii], true);
}
}
}
function uncompressDXTBlock(
destBuffer, destX, destY, destWidth, src, srcOffset, format) {
// Decoding routines follow D3D11 functional spec wrt
// endpoints unquantization and interpolation.
// Some hardware may produce slightly different values - it's normal.
function make565(src, offset) {
return src[offset + 0] + (src[offset + 1] << 8);
}
function make8888From565(c) {
// These values exactly match hw decoder when selectors are 0 or 1.
function replicateBits(v, w) {
return (v << (8 - w)) | (v >> (w + w - 8));
}
return [
replicateBits((c >> 11) & 0x1F, 5),
replicateBits((c >> 5) & 0x3F, 6),
replicateBits((c >> 0) & 0x1F, 5),
255
];
}
function mix(mult, c0, c1, div) {
var r = [];
for (var ii = 0; ii < c0.length; ++ii) {
// For green channel (6 bits), this interpolation exactly matches hw decoders
// For red and blue channels (5 bits), this interpolation exactly
// matches only some hw decoders and stays within acceptable range for others.
r[ii] = Math.floor((c0[ii] * mult + c1[ii]) / div + 0.5);
}
return r;
}
var isBC45 = ext_rgtc &&
(format == ext_rgtc.COMPRESSED_RED_RGTC1_EXT ||
format == ext_rgtc.COMPRESSED_RED_GREEN_RGTC2_EXT ||
format == ext_rgtc.COMPRESSED_SIGNED_RED_RGTC1_EXT ||
format == ext_rgtc.COMPRESSED_SIGNED_RED_GREEN_RGTC2_EXT);
let colorOffset = srcOffset;
if (!isBC45) {
var isDXT1 = format == ext.COMPRESSED_RGB_S3TC_DXT1_EXT ||
format == ext.COMPRESSED_RGBA_S3TC_DXT1_EXT;
if (!isDXT1) {
colorOffset += 8;
}
var color0 = make565(src, colorOffset + 0);
var color1 = make565(src, colorOffset + 2);
var c0gtc1 = color0 > color1 || !isDXT1;
var rgba0 = make8888From565(color0);
var rgba1 = make8888From565(color1);
var colors = [
rgba0,
rgba1,
c0gtc1 ? mix(2, rgba0, rgba1, 3) : mix(1, rgba0, rgba1, 2),
c0gtc1 ? mix(2, rgba1, rgba0, 3) : [0, 0, 0, 255]
];
}
const isSigned = ext_rgtc && (format == ext_rgtc.COMPRESSED_SIGNED_RED_RGTC1_EXT || format == ext_rgtc.COMPRESSED_SIGNED_RED_GREEN_RGTC2_EXT);
const signedSrc = new Int8Array(src);
// yea I know there is a lot of math in this inner loop.
// so sue me.
for (var yy = 0; yy < 4; ++yy) {
var pixels = src[colorOffset + 4 + yy];
for (var xx = 0; xx < 4; ++xx) {
var dstOff = ((destY + yy) * destWidth + destX + xx) * 4;
if (!isBC45) {
var code = (pixels >> (xx * 2)) & 0x3;
var srcColor = colors[code];
}
var alpha;
var rgChannel2 = 0;
let decodeAlpha = (offset) => {
let alpha;
var alpha0 = (isSigned ? signedSrc : src)[offset + 0];
var alpha1 = (isSigned ? signedSrc : src)[offset + 1];
var alphaOff = (yy >> 1) * 3 + 2;
var alphaBits =
src[offset + alphaOff + 0] +
src[offset + alphaOff + 1] * 256 +
src[offset + alphaOff + 2] * 65536;
var alphaShift = (yy % 2) * 12 + xx * 3;
var alphaCode = (alphaBits >> alphaShift) & 0x7;
if (alpha0 > alpha1) {
switch (alphaCode) {
case 0:
alpha = alpha0;
break;
case 1:
alpha = alpha1;
break;
default:
alpha = Math.floor(((8 - alphaCode) * alpha0 + (alphaCode - 1) * alpha1) / 7.0 + 0.5);
break;
}
} else {
switch (alphaCode) {
case 0:
alpha = alpha0;
break;
case 1:
alpha = alpha1;
break;
case 6:
alpha = 0;
break;
case 7:
alpha = 255;
break;
default:
alpha = Math.floor(((6 - alphaCode) * alpha0 + (alphaCode - 1) * alpha1) / 5.0 + 0.5);
break;
}
}
return alpha;
}
switch (format) {
case ext.COMPRESSED_RGB_S3TC_DXT1_EXT:
alpha = 255;
break;
case ext.COMPRESSED_RGBA_S3TC_DXT1_EXT:
alpha = (code == 3 && !c0gtc1) ? 0 : 255;
break;
case ext.COMPRESSED_RGBA_S3TC_DXT3_EXT:
{
var alpha0 = src[srcOffset + yy * 2 + (xx >> 1)];
var alpha1 = (alpha0 >> ((xx % 2) * 4)) & 0xF;
alpha = alpha1 | (alpha1 << 4);
}
break;
case ext_rgtc.COMPRESSED_RED_GREEN_RGTC2_EXT:
case ext_rgtc.COMPRESSED_SIGNED_RED_GREEN_RGTC2_EXT:
rgChannel2 = decodeAlpha(srcOffset + 8);
// FALLTHROUGH
case ext.COMPRESSED_RGBA_S3TC_DXT5_EXT:
case ext_rgtc.COMPRESSED_RED_RGTC1_EXT:
case ext_rgtc.COMPRESSED_SIGNED_RED_RGTC1_EXT:
alpha = decodeAlpha(srcOffset);
break;
default:
throw "bad format";
}
if (isBC45) {
destBuffer[dstOff + 0] = alpha;
destBuffer[dstOff + 1] = rgChannel2;
destBuffer[dstOff + 2] = 0;
destBuffer[dstOff + 3] = 255;
if (isSigned) {
destBuffer[dstOff + 0] = Math.max(0, alpha) * 2;
destBuffer[dstOff + 1] = Math.max(0, rgChannel2) * 2;
}
} else {
destBuffer[dstOff + 0] = srcColor[0];
destBuffer[dstOff + 1] = srcColor[1];
destBuffer[dstOff + 2] = srcColor[2];
destBuffer[dstOff + 3] = alpha;
}
}
}
}
function getBlockSize(format) {
var isDXT1 = format == ext.COMPRESSED_RGB_S3TC_DXT1_EXT ||
format == ext.COMPRESSED_RGBA_S3TC_DXT1_EXT;
var isBC4 = ext_rgtc && (format == ext_rgtc.COMPRESSED_RED_RGTC1_EXT || format == ext_rgtc.COMPRESSED_SIGNED_RED_RGTC1_EXT);
return isDXT1 || isBC4 ? 8 : 16;
}
function uncompressDXT(width, height, data, format) {
if (width % 4 || height % 4) throw "bad width or height";
var dest = new Uint8Array(width * height * 4);
var blocksAcross = width / 4;
var blocksDown = height / 4;
var blockSize = getBlockSize(format);
for (var yy = 0; yy < blocksDown; ++yy) {
for (var xx = 0; xx < blocksAcross; ++xx) {
uncompressDXTBlock(
dest, xx * 4, yy * 4, width, data,
(yy * blocksAcross + xx) * blockSize, format);
}
}
return dest;
}
function uncompressDXTIntoSubRegion(width, height, subX0, subY0, subWidth, subHeight, data, format)
{
if (width % 4 || height % 4 || subX0 % 4 || subY0 % 4 || subWidth % 4 || subHeight % 4)
throw "bad dimension";
var dest = new Uint8Array(width * height * 4);
// Zero-filled DXT1 or BC4/5 texture represents [0, 0, 0, 255]
if (format == ext.COMPRESSED_RGB_S3TC_DXT1_EXT || format == ext.COMPRESSED_RGBA_S3TC_DXT1_EXT ||
format == ext.COMPRESSED_RED_RGTC1_EXT || format == ext.COMPRESSED_SIGNED_RED_RGTC1_EXT ||
format == ext.COMPRESSED_RED_GREEN_RGTC2_EXT || format == ext.COMPRESSED_SIGNED_RED_GREEN_RGTC2_EXT) {
for (var i = 3; i < dest.length; i += 4) dest[i] = 255;
}
var blocksAcross = subWidth / 4;
var blocksDown = subHeight / 4;
var blockSize = getBlockSize(format);
for (var yy = 0; yy < blocksDown; ++yy) {
for (var xx = 0; xx < blocksAcross; ++xx) {
uncompressDXTBlock(
dest, subX0 + xx * 4, subY0 + yy * 4, width, data,
(yy * blocksAcross + xx) * blockSize, format);
}
}
return dest;
}
function copyRect(data, srcX, srcY, dstX, dstY, width, height, stride) {
var bytesPerLine = width * 4;
var srcOffset = srcX * 4 + srcY * stride;
var dstOffset = dstX * 4 + dstY * stride;
for (; height > 0; --height) {
for (var ii = 0; ii < bytesPerLine; ++ii) {
data[dstOffset + ii] = data[srcOffset + ii];
}
srcOffset += stride;
dstOffset += stride;
}
}
function testDXTTexture(test, useTexStorage) {
test.error = test.error || DEFAULT_COLOR_ERROR;
var data = new Uint8Array(test.data);
var width = test.width;
var height = test.height;
var format = test.format;
var uncompressedData = uncompressDXT(width, height, data, format);
canvas.width = width;
canvas.height = height;
gl.viewport(0, 0, width, height);
debug("testing " + ctu.formatToString(ext, format) + " " + width + "x" + height +
(useTexStorage ? " via texStorage2D" : " via compressedTexImage2D"));
var tex = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, tex);
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.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
if (useTexStorage) {
if (test.subData) {
var uncompressedDataSub = uncompressDXTIntoSubRegion(
width, height, test.subX0, test.subY0, test.subWidth, test.subHeight, test.subData, format);
var tex1 = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, tex1);
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.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
gl.texStorage2D(gl.TEXTURE_2D, 1, format, width, height);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "allocating compressed texture via texStorage2D");
gl.compressedTexSubImage2D(
gl.TEXTURE_2D, 0, test.subX0, test.subY0, test.subWidth, test.subHeight, format, test.subData);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "uploading compressed texture data via compressedTexSubImage2D");
wtu.clearAndDrawUnitQuad(gl);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "drawing unit quad 1");
compareRect(width, height, test.channels, uncompressedDataSub, "NEAREST", test.error);
// Clean up and recover
gl.deleteTexture(tex1);
gl.bindTexture(gl.TEXTURE_2D, tex);
}
gl.texStorage2D(gl.TEXTURE_2D, 1, format, width, height);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "allocating compressed texture via texStorage2D");
wtu.clearAndDrawUnitQuad(gl);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "drawing unit quad");
var clearColor = (test.hasAlpha ? [0, 0, 0, 0] : [0, 0, 0, 255]);
wtu.checkCanvas(gl, clearColor, "texture should be initialized to black");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width, height, format, data);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "uploading compressed texture data via compressedTexSubImage2D");
} else {
gl.compressedTexImage2D(gl.TEXTURE_2D, 0, format, width, height, 0, data);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "uploading compressed texture");
}
gl.generateMipmap(gl.TEXTURE_2D);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "trying to generate mipmaps from compressed texture");
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "after clearing generateMipmap error");
wtu.clearAndDrawUnitQuad(gl);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "drawing unit quad 1");
compareRect(width, height, test.channels, uncompressedData, "NEAREST", test.error);
// Test again with linear filtering.
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
wtu.clearAndDrawUnitQuad(gl);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "drawing unit quad 2");
compareRect(width, height, test.channels, uncompressedData, "LINEAR", test.error);
if (!useTexStorage) {
// It's not allowed to redefine textures defined via texStorage2D.
gl.compressedTexImage2D(gl.TEXTURE_2D, 0, format, width, height, 1, data);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "non 0 border");
gl.compressedTexImage2D(gl.TEXTURE_2D, 0, format, width + 4, height, 0, data);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "data size does not match dimensions");
gl.compressedTexImage2D(gl.TEXTURE_2D, 0, format, width, height + 4, 0, data);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "data size does not match dimensions");
gl.compressedTexImage2D(gl.TEXTURE_2D, 0, format, width - 4, height, 0, data);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "data size does not match dimensions");
gl.compressedTexImage2D(gl.TEXTURE_2D, 0, format, width, height - 4, 0, data);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "data size does not match dimensions");
gl.compressedTexImage2D(gl.TEXTURE_2D, 0, format, width - 1, height, 0, data);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "invalid dimensions");
gl.compressedTexImage2D(gl.TEXTURE_2D, 0, format, width - 2, height, 0, data);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "invalid dimensions");
gl.compressedTexImage2D(gl.TEXTURE_2D, 0, format, width, height - 1, 0, data);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "invalid dimensions");
gl.compressedTexImage2D(gl.TEXTURE_2D, 0, format, width, height - 2, 0, data);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "invalid dimensions");
if (width == 4) {
// The width/height of the implied base level must be a multiple of the block size.
gl.compressedTexImage2D(gl.TEXTURE_2D, 1, format, 1, height, 0, data);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "invalid dimensions for level > 0");
gl.compressedTexImage2D(gl.TEXTURE_2D, 1, format, 2, height, 0, data);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "valid dimensions for level > 0");
}
if (height == 4) {
// The width/height of the implied base level must be a multiple of the block size.
gl.compressedTexImage2D(gl.TEXTURE_2D, 1, format, width, 1, 0, data);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "invalid dimensions for level > 0");
gl.compressedTexImage2D(gl.TEXTURE_2D, 1, format, width, 2, 0, data);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "valid dimensions for level > 0");
}
}
// pick a wrong format that uses the same amount of data.
var wrongFormat;
switch (format) {
case ext.COMPRESSED_RGB_S3TC_DXT1_EXT:
wrongFormat = ext.COMPRESSED_RGBA_S3TC_DXT1_EXT;
break;
case ext.COMPRESSED_RGBA_S3TC_DXT1_EXT:
wrongFormat = ext.COMPRESSED_RGB_S3TC_DXT1_EXT;
break;
case ext.COMPRESSED_RGBA_S3TC_DXT3_EXT:
wrongFormat = ext.COMPRESSED_RGBA_S3TC_DXT5_EXT;
break;
case ext.COMPRESSED_RGBA_S3TC_DXT5_EXT:
wrongFormat = ext.COMPRESSED_RGBA_S3TC_DXT3_EXT;
break;
case ext_rgtc.COMPRESSED_RED_RGTC1_EXT:
case ext_rgtc.COMPRESSED_SIGNED_RED_RGTC1_EXT:
wrongFormat = ext_rgtc.COMPRESSED_RED_GREEN_RGTC2_EXT;
break;
case ext_rgtc.COMPRESSED_RED_GREEN_RGTC2_EXT:
case ext_rgtc.COMPRESSED_SIGNED_RED_GREEN_RGTC2_EXT:
wrongFormat = ext_rgtc.COMPRESSED_RED_RGTC1_EXT;
break;
}
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width, height, wrongFormat, data);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "format does not match");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 4, 0, width, height, format, data);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "dimension out of range");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 4, width, height, format, data);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "dimension out of range");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width + 4, height, format, data);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "data size does not match dimensions");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width, height + 4, format, data);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "data size does not match dimensions");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width - 4, height, format, data);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "data size does not match dimensions");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width, height - 4, format, data);
wtu.glErrorShouldBe(gl, gl.INVALID_VALUE, "data size does not match dimensions");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width - 1, height, format, data);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "invalid dimensions");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width - 2, height, format, data);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "invalid dimensions");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width, height - 1, format, data);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "invalid dimensions");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width, height - 2, format, data);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "invalid dimensions");
var subData = new Uint8Array(data.buffer, 0, getBlockSize(format));
if (width == 8 && height == 8) {
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 1, 0, 4, 4, format, subData);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "invalid offset");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 1, 4, 4, format, subData);
wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "invalid offset");
}
var stride = width * 4;
for (var yoff = 0; yoff < height; yoff += 4) {
for (var xoff = 0; xoff < width; xoff += 4) {
copyRect(uncompressedData, 0, 0, xoff, yoff, 4, 4, stride);
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, xoff, yoff, 4, 4, format, subData);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "uploading compressed texture");
// First test NEAREST filtering.
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
wtu.clearAndDrawUnitQuad(gl);
compareRect(width, height, test.channels, uncompressedData, "NEAREST", test.error);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "drawing unit quad");
// Next test LINEAR filtering.
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
wtu.clearAndDrawUnitQuad(gl);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "drawing unit quad");
compareRect(width, height, test.channels, uncompressedData, "LINEAR", test.error);
}
}
}
function testDXT5_RGBA_PBO() {
debug("");
debug("testing PBO uploads");
var width = 8;
var height = 8;
var channels = 4;
var data = img_8x8_rgba_dxt5;
var format = ext.COMPRESSED_RGBA_S3TC_DXT5_EXT;
var uncompressedData = uncompressDXT(width, height, data, format);
var tex = gl.createTexture();
// First, PBO size = image size
var pbo1 = gl.createBuffer();
gl.bindBuffer(gl.PIXEL_UNPACK_BUFFER, pbo1);
gl.bufferData(gl.PIXEL_UNPACK_BUFFER, data, gl.STATIC_DRAW);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "uploading a PBO");
gl.bindTexture(gl.TEXTURE_2D, tex);
gl.texStorage2D(gl.TEXTURE_2D, 1, format, width, height);
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width, height, format, data.length, 0);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "uploading a texture from a PBO");
gl.bindBuffer(gl.PIXEL_UNPACK_BUFFER, null);
wtu.clearAndDrawUnitQuad(gl);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "drawing unit quad");
compareRect(width, height, channels, uncompressedData, "NEAREST", DEFAULT_COLOR_ERROR);
// Clear the texture before the next test
gl.bindBuffer(gl.PIXEL_UNPACK_BUFFER, null);
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width, height, format, new Uint8Array(data.length));
// Second, image is just a subrange of the PBO
var pbo2 = gl.createBuffer();
gl.bindBuffer(gl.PIXEL_UNPACK_BUFFER, pbo2);
gl.bufferData(gl.PIXEL_UNPACK_BUFFER, data.length*3, gl.STATIC_DRAW);
gl.bufferSubData(gl.PIXEL_UNPACK_BUFFER, data.length, data);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "uploading a PBO subrange");
gl.compressedTexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, width, height, format, data.length, data.length);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "uploading a texture from a PBO subrange");
gl.bindBuffer(gl.PIXEL_UNPACK_BUFFER, null);
wtu.clearAndDrawUnitQuad(gl);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "drawing unit quad");
compareRect(width, height, channels, uncompressedData, "NEAREST", DEFAULT_COLOR_ERROR);
}
function compareRect(width, height, channels, expectedData, filteringMode, colorError) {
var actual = new Uint8Array(width * height * 4);
gl.readPixels(0, 0, width, height, gl.RGBA, gl.UNSIGNED_BYTE, actual);
wtu.glErrorShouldBe(gl, gl.NO_ERROR, "reading back pixels");
var div = document.createElement("div");
div.className = "testimages";
ctu.insertCaptionedImg(div, "expected", ctu.makeScaledImage(width, height, width, expectedData, true));
ctu.insertCaptionedImg(div, "actual", ctu.makeScaledImage(width, height, width, actual, true));
div.appendChild(document.createElement('br'));
document.getElementById("console").appendChild(div);
var failed = false;
for (var yy = 0; yy < height; ++yy) {
for (var xx = 0; xx < width; ++xx) {
var offset = (yy * width + xx) * 4;
var expected = expectedData.slice(offset, offset + 4);
const was = actual.slice(offset, offset + 4);
// Compare RGB values
for (var jj = 0; jj < 3; ++jj) {
if (Math.abs(was[jj] - expected[jj]) > colorError) {
failed = true;
testFailed(`RGB at (${xx}, ${yy}) expected: ${expected}` +
` +/- ${colorError}, was ${was}`);
break;
}
}
if (channels == 3) {
// BC1 RGB is allowed to be mapped to BC1 RGBA.
// In such a case, 3-color mode black value can be transparent:
// [0, 0, 0, 0] instead of [0, 0, 0, 255].
if (actual[offset + 3] != expected[3]) {
// Got non-opaque value for opaque format
// Check RGB values. Notice, that the condition here
// is more permissive than needed since we don't have
// compressed data at this point.
if (was[0] == 0 &&
was[1] == 0 &&
was[2] == 0 &&
was[3] == 0) {
debug("<b>DXT1 RGB is mapped to DXT1 RGBA</b>");
} else {
failed = true;
testFailed('Alpha at (' + xx + ', ' + yy +
') expected: ' + expected[3] + ' was ' + was);
}
}
} else {
// Compare Alpha values
// Acceptable interpolation error depends on endpoints:
// 1.0 / 65535.0 + 0.03 * max(abs(endpoint0 - endpoint1), abs(endpoint0_p - endpoint1_p))
// For simplicity, assume the worst case (e0 is 0.0, e1 is 1.0). After conversion to unorm8, it is 8.
if (Math.abs(was[3] - expected[3]) > 8) {
failed = true;
testFailed('Alpha at (' + xx + ', ' + yy +
') expected: ' + expected + ' +/- 8 was ' + was);
}
}
}
}
if (!failed) {
testPassed("texture rendered correctly with " + filteringMode + " filtering");
}
}
debug("");
var successfullyParsed = true;
</script>
<script src="../../js/js-test-post.js"></script>
</body>
</html>