32188 2009-12-05 20:57:36 -0800 texImage2D pixel junk for transparency 2009-12-06 03:38:11 -0800 1 1 1 Unclassified WebKit WebGL 528+ (Nightly build) Mac OS X 10.6 RESOLVED FIXED P2 Major --- 1 OneSadCookie webkit-unassigned oliver oldest_to_newest 169062 0 OneSadCookie 2009-12-05 20:57:36 -0800 When using texImage2D with an Image or Canvas as the source of the data, WebKit draws the underlying CGImage to a CGBitmapContext to get access to the pixels. The context is created with memory from fastMalloc(), and therefore undefined. When the CGImage being drawn contains transparency, this undefined data shows through, causing pixel junk in the resulting WebGL texture image. There is no workaround for this; there is no way to affect the pixels of that CGBitmapContext in such a way that the pixel junk is cleared without also making the resulting texture opaque. The patch is trivial (using calloc, or adding a memset, or CGClearRect, or similar to zero the bitmap context's data before drawing the image in imageToTexture() in WebCore/platform/graphics/mac/GraphicsContext3DMac.cpp. I'm having trouble building WebKit though so I can't offer a tested patch. 169084 1 oliver 2009-12-06 02:47:31 -0800 This problem can be fixed by forcing the blend mode to kCGBlendCopy. Have a patch in my tree, but haven't yet worked out how to make a testcase. 169085 2 44359 oliver 2009-12-06 03:30:19 -0800 Created attachment 44359 Patch 169086 3 44359 mjs 2009-12-06 03:33:37 -0800 Comment on attachment 44359 Patch r=me 169087 4 oliver 2009-12-06 03:38:11 -0800 Committed r51740 44359 2009-12-06 03:30:19 -0800 2009-12-06 03:33:36 -0800 Patch bug-32188-20091206033018.patch text/plain 1626 oliver ZGlmZiAtLWdpdCBhL1dlYkNvcmUvQ2hhbmdlTG9nIGIvV2ViQ29yZS9DaGFuZ2VMb2cKaW5kZXgg ZjBlOThjNy4uMzMxMTg1YSAxMDA2NDQKLS0tIGEvV2ViQ29yZS9DaGFuZ2VMb2cKKysrIGIvV2Vi Q29yZS9DaGFuZ2VMb2cKQEAgLTEsMyArMSwxOSBAQAorMjAwOS0xMi0wNiAgT2xpdmVyIEh1bnQg IDxvbGl2ZXJAYXBwbGUuY29tPgorCisgICAgICAgIFJldmlld2VkIGJ5IE5PQk9EWSAoT09QUyEp LgorCisgICAgICAgIHRleEltYWdlMkQgcGl4ZWwganVuayBmb3IgdHJhbnNwYXJlbmN5CisgICAg ICAgIGh0dHBzOi8vYnVncy53ZWJraXQub3JnL3Nob3dfYnVnLmNnaT9pZD0zMjE4OAorCisgICAg ICAgIFVzZSBrQ0dCbGVuZE1vZGVDb3B5IHdoZW4gZHJhd2luZyBhbiBpbWFnZSB0byB0aGUgaW50 ZXJtZWRpYXRlIGNvbnRleHQKKyAgICAgICAgdXNlZCB0byBjcmVhdGUgYSBHTCB0ZXh0dXJlLgor CisgICAgICAgIE5vIHRlc3QgYXMgd2UgZG9uJ3QgY3VycmVudGx5IGhhdmUgYW55IG1lY2hhbmlz bSB0byByZXRyaWV2ZSBwaXhlbCBkYXRhCisgICAgICAgIGZyb20gdGhlIHdlYmdsIGNvbnRleHQu CisKKyAgICAgICAgKiBwbGF0Zm9ybS9ncmFwaGljcy9tYWMvR3JhcGhpY3NDb250ZXh0M0RNYWMu Y3BwOgorICAgICAgICAoV2ViQ29yZTo6aW1hZ2VUb1RleHR1cmUpOgorCiAyMDA5LTEyLTAzICBQ aGlsaXBwZSBOb3JtYW5kICA8cG5vcm1hbmRAaWdhbGlhLmNvbT4KIAogICAgICAgICBSZXZpZXdl ZCBieSBHdXN0YXZvIE5vcm9uaGEuCmRpZmYgLS1naXQgYS9XZWJDb3JlL3BsYXRmb3JtL2dyYXBo aWNzL21hYy9HcmFwaGljc0NvbnRleHQzRE1hYy5jcHAgYi9XZWJDb3JlL3BsYXRmb3JtL2dyYXBo aWNzL21hYy9HcmFwaGljc0NvbnRleHQzRE1hYy5jcHAKaW5kZXggMzllNTMzNi4uMDcxZTJkMCAx MDA2NDQKLS0tIGEvV2ViQ29yZS9wbGF0Zm9ybS9ncmFwaGljcy9tYWMvR3JhcGhpY3NDb250ZXh0 M0RNYWMuY3BwCisrKyBiL1dlYkNvcmUvcGxhdGZvcm0vZ3JhcGhpY3MvbWFjL0dyYXBoaWNzQ29u dGV4dDNETWFjLmNwcApAQCAtMTEzMiw3ICsxMTMyLDcgQEAgc3RhdGljIHZvaWQgaW1hZ2VUb1Rl eHR1cmUoSW1hZ2UqIGltYWdlLCB1bnNpZ25lZCB0YXJnZXQsIHVuc2lnbmVkIGxldmVsKQogICAg ICAgICAKICAgICBDR0NvbnRleHRSZWYgdGV4dHVyZUNvbnRleHQgPSBDR0JpdG1hcENvbnRleHRD cmVhdGUodGV4dHVyZURhdGEsIHRleHR1cmVXaWR0aCwgdGV4dHVyZUhlaWdodCwgOCwgdGV4dHVy ZVdpZHRoICogNCwgCiAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg ICAgICAgICAgICAgIENHSW1hZ2VHZXRDb2xvclNwYWNlKHRleHR1cmVJbWFnZSksIGtDR0ltYWdl QWxwaGFQcmVtdWx0aXBsaWVkTGFzdCk7Ci0gICAgCisgICAgQ0dDb250ZXh0U2V0QmxlbmRNb2Rl KHRleHR1cmVDb250ZXh0LCBrQ0dCbGVuZE1vZGVDb3B5KTsKICAgICBDR0NvbnRleHREcmF3SW1h Z2UodGV4dHVyZUNvbnRleHQsIENHUmVjdE1ha2UoMCwgMCwgKENHRmxvYXQpdGV4dHVyZVdpZHRo LCAoQ0dGbG9hdCl0ZXh0dXJlSGVpZ2h0KSwgdGV4dHVyZUltYWdlKTsKICAgICBDR0NvbnRleHRS ZWxlYXNlKHRleHR1cmVDb250ZXh0KTsKICAgICAK