Hi Everyone,
I'm experiencing a strange behavior with display lists.
I've built a sample project (VS Solution) to demonstrate the issue, you can find the files here.
I'll try my best to summarize the description of this issue (please refer to the project for the details):
If I generate some display lists like the following:
// create some display lists
// -------------------------
unsigned int line1List = 0;
//---------------------- LINE 1 COMPILE ---------------------- //
glDeleteLists(line1List, 1);
line1List = glGenLists(1);
glNewList(line1List, GL_COMPILE);
glBegin(GL_LINES);
{
glVertex3f(-0.66, -0.9, 0);
glVertex3f(-0.66, 0.9, 0);
}
glEnd();
glEndList();
unsigned int line2List = 0;
//---------------------- LINE 2 COMPILE ---------------------- //
// same ...
//---------------------- LINE 3 COMPILE ---------------------- //
// same ...
And use this simple program to do the rendering:
const std::string VS_SOURCE =
R"(
void main(void)
{
gl_FrontColor = gl_Color;
gl_Position = ftransform();
}
)";
const std::string FS_SOURCE =
R"(
void main(void)
{
vec4 finalColor;
finalColor = gl_Color;
finalColor = clamp (finalColor, 0.0, 1.0);
gl_FragColor = finalColor;
}
)";
I get wrong colors (see the code in the following picture) the first time the display lists are drawn:
This problem occurs with the Radeon Pro W5500 while it doesn't occur when using the Quadro P2000.
I know I'm using old OpenGL features and vertex attribute values not provided per vertex, and I'm going to get rid of all of that one day.
However I'd like to ask if and how I could temporarily solve the issue.
