strange thing with glEdgeFlagPointer
Hello!
I have strange problem with latest ATI drivers on Radeon 9550/X1100 Series (tested with Catalyst 8.7,8.6,8.5). I think that it is a driver problem because with very old drivers everything works fine (I tested with Catalyst 6.5 Release date: xx.xx.2006).
I wrote a test application and tested it on 2 PC's with Windows XP SP2 and Windows XP SP3. with Catalyst 8.7,8.6,8.5. The problem repeats...
The problem:
First, I render a group of triangles with
glPolygonMode(GL_FRONT_AND_BACK,GL_FILL) using GL_VERTEX_ARRAY,
then render the same triangles with glPolygonMode(GL_FRONT_AND_BACK,GL_LINE) using GL_VERTEX_ARRAY and GL_EDGE_FLAG_ARRAY and here something strange happens...Some of triangles that must be filled with color won't draw at all.
Here is some screenshots:
[or if html won't work] http://s46.radikal.ru/i114/0808/50/98f6fd02172ct.jpg
This is a first frame of app...Last triangle must be filled with "teal", however, as you can see this is not true, it filled red.
[or if html won't work]http://s56.radikal.ru/i153/0808/33/857d94b0ee1ct.jpg
This is one of another frames. Another strange thing...(detailes on screenshot).
Here is the source code of application (it is just a demo example):
I used glut 3.7.6. I dont think that this problem related with glut, I can rewrite this app using win32 api only if needed. (bad English...sorry...)
Source code:
[source lang="cpp"]
#include <windows.h>
#include <gl/gl.h>
#include <gl/glut.h>
//first group of triangles
const GLfloat triangle_vertexes[] ={1,100.0f, 70.0f,90.0f, 1.0f,1.0f
,30.0f,160.0f, 80.0f,70.0f, 60.0f,15.0f
,40.0f,60.0f, 120.0f,100.0f, 130.0f,110.0f
,40.0f,50.0f, 120.0f,90.0f, 130.0f,20.0f};
//second group of triangles (1 triangle)
const GLfloat triangle_vertexes2[] = {120.0f,12.0f, 40.0f,80.0f, 10.0f,110.0f};
//edge flags of the first group
const GLboolean edge_flags[] = { true ,false,false
,true ,true ,false
,false,false,false
,true ,true ,true};
//edge flags of the second group
const GLboolean edge_flags2[] = {true,true,true};
GLfloat angle = 0;
int size_x;
int size_y;
bool increment = true;
void Reshape (int w,int h)
{
glViewport(0,0,w,h);
size_x = w;
size_y = h;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0,w/8,0,h/8,-1,1);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
void Display (void)
{
glClearColor(1.0f,1.0f,1.0f,1.0f);
glClear(GL_COLOR_BUFFER_BIT);
//Change modelview matrix
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glRotatef(angle,0,0,-1.0f);
//Draw first group of triangles
glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);
glVertexPointer(2,GL_FLOAT,0,triangle_vertexes);
glEnableClientState(GL_VERTEX_ARRAY);
glColor3f(1.0f,0,0);
glDrawArrays(GL_TRIANGLES,0,sizeof(triangle_vertexes)/sizeof(GLfloat));
glEnable(GL_POLYGON_OFFSET_FILL);
glPolygonOffset(1.0, 1.0);
//Draw borders with edge flags
glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
glEnable(GL_BLEND);
glEdgeFlagPointer(0,edge_flags);
glEnableClientState(GL_EDGE_FLAG_ARRAY);
glColor3f(0,1,0);
glDrawArrays(GL_TRIANGLES,0,sizeof(triangle_vertexes)/sizeof(GLfloat));
glDisable(GL_BLEND);
glDisableClientState(GL_EDGE_FLAG_ARRAY);
//Change modelview matrix
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glRotatef(angle,0,0,1.0f);
//Draw second group of triangles (1 triangle actually )
glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);
glVertexPointer(2,GL_FLOAT,0,triangle_vertexes2);
glColor3f(0,0.5f,0.5f);
glDrawArrays(GL_TRIANGLES,0,sizeof(triangle_vertexes2)/sizeof(GLfloat));
//Draw its border with edge flags
glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
glEnable(GL_BLEND);
glColor3f(0,1,0);
glEdgeFlagPointer(0,edge_flags2);
glEnableClientState(GL_EDGE_FLAG_ARRAY);
glDrawArrays(GL_TRIANGLES,0,sizeof(triangle_vertexes2)/sizeof(GLfloat));
glDisableClientState(GL_EDGE_FLAG_ARRAY);
glDisable(GL_BLEND);
glDisableClientState(GL_VERTEX_ARRAY);
//Change angle
if (increment)
{
angle+=5.0f;
if (angle>25.0)
increment = false;
}
else
{
angle-=5.0f;
if (angle<-25.0)
increment = true;
}
glutSwapBuffers();
}
void Init (void)
{
//we want antialiased triangle border
glEnable(GL_LINE_SMOOTH);
glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
//set flat shading
glShadeModel(GL_FLAT);
}
void TimerFunc (int some)
{
glutPostRedisplay();
glutTimerFunc(500,TimerFunc,0);
}
int main (int argc,char **argv)
{
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGBA);
glutInitWindowSize(1024,1024);
glutInitWindowPosition(100,100);
glutCreateWindow("Problem_demo");
glutDisplayFunc(Display);
glutReshapeFunc(Reshape);
Init();
glutTimerFunc(1000,TimerFunc,0);
glutMainLoop();
return 0;
}
[/source]
The question is if it is a driver problem or am I doing something wrong? By the way, i tried this example on some NVIDIA cards (GeForce 9400 GT M and GeForce 8400 M GS) and everything works fine. I also tried Microsoft generic implementation it works fine to.
P.S. Please sorry for my awful English.
