QNX RTOS v4 Knowledge Base
QNX RTOS v4 Knowledge Base
| Title |
Get transparent color from a GIF |
| Ref. No. |
QNX.000009884 |
| Category(ies) |
Development |
| Issue |
How do we determine the transparent color of an image when using PxLoadImage()?
Is it possible to do that in the HTML widget?
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| Solution |
The current GIF loader does not allow you to determine the transparent color.
However, you can specify a color that will get substituted in for the transparent color by doing the following:
x09- set the PX_TRANSPARENT bit in the flags member of the PxMethods_t that gets passed into PxLoadImage
x09- set the transparent member of the PxMethods_t struct to a suitable color for the transparency mask (e.g. PgRGB(255, 255, 0) for a nice bright yellow).
Once the GIF has been loaded, you can use PhMakeTransBitmap() to create a transparency bitmap for the image (using the color you specified earlier, PgRGB(255, 255, 0)) and then render the transparency image with PgDrawTImage(). |
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