Hi everyone , please teach me.
I want to get min and max color of layered-texture using EXT_blend_minmax.
When background color is black , and success to get max color using glBlendEquationEXT( GL_MAX_EXT );
But , I can’t get min color using glBlendEquationEXT( GL_MIN_EXT );
( Always get black images ).
Perhaps , GL_MIN_EXT get backgound color for min-color.
My work requires black backgound color , so can’t solve with white-backgound.
Please teach me , how to except background color on glBlendEquationEXT.
Originally posted by ysatou:
Please teach me , how to except background color on glBlendEquationEXT.
How about enabling GL_ALPHA_TEST with a threshold of zero or thereabouts ?
That should prevent low-value elements from going into the blend.
Karthik
Thanks for your reply.
I try to following code.
But , background color is blended , and failed( only display black image ).
glEnable( GL_BLEND );
glBlendFunc( GL_ONE , GL_ONE );
glEnable( GL_ALPHA_TEST );
glAlphaFunc( GL_GREATER , 0.0 );
glBlendEquation( GL_MIN_EXT );
glClearColor( 0,0,0,0 );
glClear( GL_COLOR_BUFFER_BIT );
glColor4f( 1,1,1,1 );
glRectf( -0.5 , -0.5 , 0.5 , 0.5 );