From: Keith Parkins (kparkins++at++cs.rochester.edu)
Date: 01/16/2003 08:36:53
I am trying to create an airbush effect with the following code but have a
problem. When I run the code (which is executed in a channel postdraw) the
brush mark appears for a second before dissapearing. Any ideas?
void
drawScotoma(int split_x, int split_y)
{
float radius = 50.0f;
int i;
int old_mode;
old_mode = pfGetTransparency();
pfTransparency(PFTR_ON);
for (i = 0; i < 36; i ++) {
float angle1, angle2;
angle1 = 2 * M_PI * i / 36.0;
angle2 = 2 * M_PI * (i+1) / 36.0;
glBegin(GL_POLYGON);
glColor4f(0.0, 0.0, 0.0, 0.0);
glVertex2f(radius * cos(angle1) + split_x,
radius * sin(angle1) + split_y);
glVertex2f(radius * cos(angle2) + split_x,
radius * sin(angle2) + split_y);
glColor4f(0.0, 0.0, 0.0, 1.0);
glVertex2f(split_x, split_y);
glEnd();
}
pfTransparency(old_mode);
}
Keith Parkins U of R Computer Science
kparkins++at++cs.rochester.edu Computer Science Building, Room 606
(585) 275-1118
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