// Hemi is Upper or Lower. Zero is not acceptable.
// The current texture is used. SKYHEMI_NO_TOPCAP can be used.
void GL_RenderSkyHemisphere(int hemi)
{
int r, c;
if (hemi & SKYHEMI_LOWER)
{
yflip = true;
}
else
{
yflip = false;
}
// The top row (row 0) is the one that's faded out.
// There must be at least 4 columns. The preferable number
// is 4n, where n is 1, 2, 3... There should be at least
// two rows because the first one is always faded.
rows = 4;
columns = 4 * (gl_sky_detail > 0 ? gl_sky_detail : 1);
if (hemi & SKYHEMI_JUST_CAP)
{
return;
}
// The total number of triangles per hemisphere can be calculated
// as follows: rows * columns * 2 + 2 (for the top cap).
for(r = 0; r < rows; r++)
{
if (yflip)
{
glBegin(GL_TRIANGLE_STRIP);
SkyVertex(r + 1, 0);
SkyVertex(r, 0);
for(c = 1; c <= columns; c++)
{
SkyVertex(r + 1, c);
SkyVertex(r, c);
}
glEnd();
}
else
{
glBegin(GL_TRIANGLE_STRIP);
SkyVertex(r, 0);
SkyVertex(r + 1, 0);
for(c = 1; c <= columns; c++)
{
SkyVertex(r, c);
SkyVertex(r + 1, c);
}
glEnd();
}
}
}
void FSkyVertexBuffer::CreateSkyHemisphere(int hemi)
{
int r, c;
bool yflip = !!(hemi & SKYHEMI_LOWER);
mPrimStart.Push(mVertices.Size());
for (c = 0; c < mColumns; c++)
{
SkyVertex(1, c, yflip);
}
// The total number of triangles per hemisphere can be calculated
// as follows: rows * columns * 2 + 2 (for the top cap).
for (r = 0; r < mRows; r++)
{
mPrimStart.Push(mVertices.Size());
for (c = 0; c <= mColumns; c++)
{
SkyVertex(r + yflip, c, yflip);
SkyVertex(r + 1 - yflip, c, yflip);
}
}
}
static void RenderSkyHemisphere(int hemi, bool mirror)
{
int r, c;
if (hemi & SKYHEMI_LOWER)
{
yflip = true;
}
else
{
yflip = false;
}
skymirror = mirror;
// The top row (row 0) is the one that's faded out.
// There must be at least 4 columns. The preferable number
// is 4n, where n is 1, 2, 3... There should be at least
// two rows because the first one is always faded.
rows = 4;
if (hemi & SKYHEMI_JUST_CAP)
{
return;
}
// Draw the cap as one solid color polygon
if (!foglayer)
{
columns = 4 * (gl_sky_detail > 0 ? gl_sky_detail : 1);
foglayer=true;
gl_RenderState.EnableTexture(false);
gl_RenderState.Apply(true);
if (!secondlayer)
{
glColor3f(R, G ,B);
glBegin(GL_TRIANGLE_FAN);
for(c = 0; c < columns; c++)
{
SkyVertex(1, c);
}
glEnd();
}
gl_RenderState.EnableTexture(true);
foglayer=false;
gl_RenderState.Apply();
}
else
{
gl_RenderState.Apply(true);
columns=4; // no need to do more!
glBegin(GL_TRIANGLE_FAN);
for(c = 0; c < columns; c++)
{
SkyVertex(0, c);
}
glEnd();
}
// The total number of triangles per hemisphere can be calculated
// as follows: rows * columns * 2 + 2 (for the top cap).
for(r = 0; r < rows; r++)
{
if (yflip)
{
glBegin(GL_TRIANGLE_STRIP);
SkyVertex(r + 1, 0);
SkyVertex(r, 0);
for(c = 1; c <= columns; c++)
{
SkyVertex(r + 1, c);
SkyVertex(r, c);
}
glEnd();
}
else
{
glBegin(GL_TRIANGLE_STRIP);
SkyVertex(r, 0);
SkyVertex(r + 1, 0);
for(c = 1; c <= columns; c++)
{
SkyVertex(r, c);
SkyVertex(r + 1, c);
}
glEnd();
}
}
}
