Original Post
Untill now I've used fullscreen mode with the NeHeGL basecode and have had no problems. But now, I'm makeing a terrain engine for my game and strech a texture (tga) across the whole map. Here's the texture: 
When I run the program in "not fullscreen" mode and then maximize the window it looks like this: 
But when I run it in fullscreen mode it looks like this: 
And here's the rendering code: In the pictures above g_bDetail = false; The texture looks very,...Strange:( All the pixels are blocky and everything, even the clouds (skybox texture) are messed up. I know that the fullscreen enlarges the picture but I've never gotten anything like this before? What could the problem be? Please tell me if I've left out important information. Thanks!
When I run the program in "not fullscreen" mode and then maximize the window it looks like this: But when I run it in fullscreen mode it looks like this: And here's the rendering code:
glLoadIdentity();
Camera.Look();
//glDisable(GL_ALPHA_TEST);
glDepthMask(GL_TRUE);
glDisable(GL_BLEND);
// Activate the first texture ID and bind the tree background to it
glActiveTextureARB(GL_TEXTURE0_ARB);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, g_Texture[0]);
// If we want detail texturing on, let's render the second texture
if(g_bDetail)
{
// Activate the second texture ID and bind the fog texture to it
glActiveTextureARB(GL_TEXTURE1_ARB);
glEnable(GL_TEXTURE_2D);
// Here we turn on the COMBINE properties and increase our RGB
// gamma for the detail texture. 2 seems to work just right.
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_EXT);
glTexEnvi(GL_TEXTURE_ENV, GL_RGB_SCALE_EXT, 2);
// Bind the detail texture
glBindTexture(GL_TEXTURE_2D, g_Texture[1]);
// Now we want to enter the texture matrix. This will allow us
// to change the tiling of the detail texture.
glMatrixMode(GL_TEXTURE);
// Reset the current matrix and apply our chosen scale value
glLoadIdentity();
glScalef((float)g_DetailScale, (float)g_DetailScale, 1);
// Leave the texture matrix and set us back in the model view matrix
glMatrixMode(GL_MODELVIEW);
}
//if(Frustum.BoxInFrustum( 0, 0, 0, 100, 100, 100 ))
Render(map);
glPolygonMode( GL_FRONT_AND_BACK, GL_FILL);
// Turn the second multitexture pass off
glActiveTextureARB(GL_TEXTURE1_ARB);
glDisable(GL_TEXTURE_2D);
// Turn the first multitexture pass off
glActiveTextureARB(GL_TEXTURE0_ARB);
glDisable(GL_TEXTURE_2D);
glEnable(GL_TEXTURE_2D);
...
//.....................the Render function....................
// The Render function is passed a pointer that points to the root
// node of a quadtree, then it check which nodes are visible and renders
// them with the RenderHeightMap function which renders a portion of the map
//.............................................................
void RenderHeightMap(BYTE pHeightMap[], int startX, int startY, int endX, int endY)
{
int X = 0, Y = 0;
float x, y, z;
// float scaleside=20, scalehieght = 8;
bool bSwitchSides = false;
if(render)
glPolygonMode( GL_FRONT_AND_BACK, GL_FILL);
if(!render)
glPolygonMode( GL_FRONT_AND_BACK, GL_LINE);
glEnable(GL_BLEND);
for ( X = startX; X <= endX-STEP_SIZE; X += STEP_SIZE )
{
glBegin( GL_TRIANGLE_STRIP );
for ( Y = startY; Y <= endY-STEP_SIZE; Y += STEP_SIZE )
{
//////////
x = (float)X;
y = (float)(SCALE_HEIGHT*Height(pHeightMap,
(float)X, (float)Y ));
z = (float)Y;
SetTextureCoord( (float)x, (float)z );
glVertex3f(x*SCALE_SIDE, y, z*SCALE_SIDE);
///////////////////////////////
x = (float)(X + STEP_SIZE);
y = (float)(SCALE_HEIGHT*Height(pHeightMap,
(float)(X + STEP_SIZE), (float)Y ));
z = (float)Y;
SetTextureCoord( (float)x, (float)z );
glVertex3f(x*SCALE_SIDE, y, z*SCALE_SIDE);
/////////////
x = (float)X;
y = (float)(SCALE_HEIGHT*Height(pHeightMap, (float)X,
(float)(Y + STEP_SIZE) ));
z = (float)(Y + STEP_SIZE);
SetTextureCoord( (float)x, (float)z );
glVertex3f(x*SCALE_SIDE, y, z*SCALE_SIDE);
////////////////////
x = (float)(X + STEP_SIZE);
y = (float)(SCALE_HEIGHT*Height(pHeightMap,
(float)(X + STEP_SIZE), (float)(Y + STEP_SIZE) ));
z = (float)(Y + STEP_SIZE);
SetTextureCoord( (float)x, (float)z );
glVertex3f(x*SCALE_SIDE, y, z*SCALE_SIDE);
}
glEnd();
}
glDisable(GL_BLEND);
// Stop rendering triangle strips
}
