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[Brunni]

Hello all ^^

I have a RGBA image that I use as a simple sprite, it's usually 5551 (just 1 bit to define if the pixel is transparent or not). Up to here, I used:
sceGuBlendFunc(GU_ADD,GU_ONE_MINUS_SRC_ALPHA,GU_SRC_ALPHA,0,0);
This will work, if the bit is 1, then it's transparent, else not.
But now, I want to add a global alpha value to my sprite, so that it's semi-transparent. Usually, I just do:
sceGuBlendFunc(GU_ADD, GU_FIX, GU_FIX, coeff, 0xffffffff-coeff);
Where coeff can be 0x00808080 for semi-transparency. It works, but the problem is that this won't take the alpha value in consideration and the transparent sprite part will be drawn as solid black...

The goal would be a blendfunction that multiplies GU_SRC_ALPHA by a fixed value, like GU_ONE_MINUS_SRC_ALPHA * GU_FIX and GU_SRC_ALPHA * GU_FIX, but it seems not to be possible regarding the documentation.

If anyone can help me, I would really appreciate, thanks :)
_________________
Sorry for my bad english
Oldschool library for PSP - PC version released

[jsgf]

You could do it that way, I guess, but the more conventional approach is to use the current colour to modulate the texture pixels.

Use:

[Brunni]

Thanks, it works, but the problem is that my alpha is opaque when 0 and transparent when 1, because it's for a library and I don't want to fill my buffers with 0xff000000 by default.
sceGuBlendFunc(GU_ADD,GU_ONE_MINUS_SRC_ALPHA,GU_SRC_ALPHA,0,0);
sceGuTexFunc(GU_TFX_MODULATE, GU_TCC_RGBA);
sceGuAmbientColor(coeff<<24);
If I do that, it will multiply them and they will become more opaque instead of more transparent :(
In fact I would need to make something like Av=(1-At)*Af but sceGuTexFunc doesn't permit this.
Any solution?
_________________
Sorry for my bad english
Oldschool library for PSP - PC version released