drawline ignores rgb parameters. Sometimes.

Ladies and Gentlemen,

I have encountered an interesting problem.
I am writing a bit of code that generate rectangles in a 3D view.
Problem is the generated rectanges appear black in 3D view regardless of the RGB values I pass to the drawline().
As soon as I drop a single object into the view, the problem disappears and reappears again if I delete this object. What am I doing wrong?




Black:



I drop in a processor and the color appears:



Here is a snippet of a code that draws the box:

// OnDraw
treenode current = parnode(1);
treenode view = parnode(2);
treenode blockMetadata = parnode(3);
drawtomodelscale(current);
// .....
DrawBox(view, xbo, ybo, rz, sx, sy, xo, yo, zo, 1, 0, 0);
drawtoobjectscale(current);
return 1;
// DrawBox
/**Draw a box on the ground*/
treenode view = parnode(1);
double x      = parval (2); 
double y      = parval (3); 
double theta  = parval (4); 
double width  = parval (5); 
double depth  = parval (6);  
double xOrigin= parval (7); 
double yOrigin= parval (8); 
double zOrigin= parval (9);
double r      = parval (10); 
double g      = parval (11); 
double b      = parval (12);
double x1 = (x) + width/2.0 * cos(degreestoradians(theta));
double y1 = (y) + width/2.0 * sin(degreestoradians(theta));
double x2 = (x) + width/2.0 * cos(degreestoradians(theta+180));
double y2 = (y) + width/2.0 * sin(degreestoradians(theta+180));
// Corners
double xc0 = (x1) + (depth/2.0) * cos(degreestoradians(theta+90));
double yc0 = (y1) + (depth/2.0) * sin(degreestoradians(theta+90));
double xc1 = (x1) + (depth/2.0) * cos(degreestoradians(theta-90));
double yc1 = (y1) + (depth/2.0) * sin(degreestoradians(theta-90));
double xc2 = (x2) + (depth/2.0) * cos(degreestoradians(theta-90));
double yc2 = (y2) + (depth/2.0) * sin(degreestoradians(theta-90));
double xc3 = (x2) + (depth/2.0) * cos(degreestoradians(theta+90));
double yc3 = (y2) + (depth/2.0) * sin(degreestoradians(theta+90));
drawline(view, xc0 - xOrigin, yc0 - yOrigin, -zOrigin, xc1 - xOrigin, yc1 - yOrigin, -zOrigin, r, g, b);
drawline(view, xc1 - xOrigin, yc1 - yOrigin, -zOrigin, xc2 - xOrigin, yc2 - yOrigin, -zOrigin, r, g, b);
drawline(view, xc2 - xOrigin, yc2 - yOrigin, -zOrigin, xc3 - xOrigin, yc3 - yOrigin, -zOrigin, r, g, b);
drawline(view, xc0 - xOrigin, yc0 - yOrigin, -zOrigin, xc3 - xOrigin, yc3 - yOrigin, -zOrigin, r, g, b);
// Centroid
double offset = min(width, depth)/10.0;
drawline(view, x - xOrigin + offset, y - yOrigin + offset, -zOrigin, x - xOrigin - offset, y - yOrigin - offset, -zOrigin, r, g, b);
drawline(view, x - xOrigin - offset, y - yOrigin + offset, -zOrigin, x - xOrigin + offset, y - yOrigin - offset, -zOrigin, r, g, b);

I dont get the colour disapearing when draw this, but the lines arent drawn completly.
This changes when I add a processor in as above.

The way I can see to get around this is to add:
glDisable(GL_TEXTURE_2D);
at the top of your draw box command and then:
glEnable(GL_TEXTURE_2D);
at the end.

It looks like there is a slight issue in the implementation of the drawline command which is causing the textures to get messed up. drawtext has a similar problem.

To optimize the graphics rendering speed, we no longer set the OpenGL state to default values before calling OnDraw. Because of this, it may be in a strange state (such as having textures turned on and a texture available to draw).

Adding a glDisable(GL_TEXTURE_2D) before calling drawline() should fix the problem.

The reason it changes when you add a processor is because the opengl state is different depending on what object was drawn previously.