Thread: OpenGL

I don't want to fade to white.

I want to have what they saw BEFORE the flashbang (except inverted) slowly fade into what the current view is

EDIT:

Code:

for (int x=0; x<30; x++)
	{
		for (int y=0; y<30; y++)
		{
			GLfloat pixel[33*3*33*3]; 

			glReadPixels(x, y, 1, 1, GL_RGB, GL_FLOAT,(GLvoid *)pixel);

			pixel[0] = 255 - pixel[0];
			pixel[1] = 255 - pixel[1];
			pixel[2] = 255 - pixel[2];

			glRasterPos2i (x, y); 
			glDrawPixels (1, 1, GL_RGB, GL_FLOAT, (GLvoid *)pixel);
		}
	}
	return;

Thats my attempt to do the invert part and then draw it, but that doesn't do anything to the screen. Whats wrong with it?

Also, there must be a way to do it all at once instead of pixel by pixel... GL_BITMAP, probably, but I have no idea how it works.

Well you could get a pointer to the screen and do it in inline assembly. The reason I say assembly language is because you could use MMX to operate on 64-bits at a time thus being able to fade and plot 2 pixels in 32-bit color in very few cycles. MMX also uses saturated arithmetic which means that data types will not overflow or wrap around - not all MMX functions use this, but there are some that do.

If OpenGL does not natively support what you want to do, my advice would be to use MMX to at least alter the frame buffer and then let GL render it.

By the way I'm not familiar with GL, but if each of your pixels is composed of RGBA components - hence b+(g<<8)+(r<<16)+(a<<24) - subtracting 255 from the entire pixel value will do nothing. You must operate on each color component, not the whole value to affect the color correctly. Your method looks like it might work in 256 color mode, but thats about it.