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xdanieldzd / GXTConvert

Somewhat rudimentary PS Vita GXT to PNG converter - UNMAINTAINED
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Weirdly placed transparent pixels in decompressed Ultra Despair Girl GXT conversions #3

Closed internetakias closed 8 years ago

internetakias commented 8 years ago

bg_street01pic00 texture 0 Original files: bg_street01pic00.zip

xdanieldzd commented 8 years ago

That specific file uses compressed DXT1 image data, which I had assumed to be in RGBA mode (based on what DXT1/UBC1's entry in SceGxmTextureFormat might imply, and the OpenGL COMPRESSED_RGBA_S3TC_DXT1_EXT specs). This assumption appears to be incorrect and the Vita's DXT1 data is RGB-only, which, when treated according to the aforementioned RGBA mode specs, caused transparent pixels to appear where they shouldn't.

I have removed the RGBA support from GXTConvert's DXT1 code in commit 6b0ec70, which should fix this issue for this and any other DXT1/UBC1-format GXTs with incorrect transparent pixels.