Function GetFaceAlpha

Descent3/render.cpp:239–253

Determines if a face draws with alpha blending Parameters: fp - pointer to the face in question bm_handle - the handle for the bitmap for this frame, or -1 if don't care about transparence Returns: bitmask describing the alpha blending for the face the return bits are the ATF_ flags in renderer.h

// transparence Returns:		bitmask describing the alpha blending for the face
// the return bits are the ATF_ flags in renderer.h
static inline int GetFaceAlpha(face *fp, int bm_handle) {
  int ret = AT_ALWAYS;
  if (GameTextures[fp->tmap].flags & TF_SATURATE) {
    ret = AT_SATURATE_TEXTURE;
  } else {
    // Check the face's texture for an alpha value
    if (GameTextures[fp->tmap].alpha < 1.0)
      ret |= ATF_CONSTANT;

    // Check for transparency
    if (GameBitmaps[bm_handle].format != BITMAP_FORMAT_4444 && GameTextures[fp->tmap].flags & TF_TMAP2)
      ret |= ATF_TEXTURE;
  }
  return ret;
}
// Determine if you should render through a portal
// Parameters:	rp - the room the portal is in
//					pp - the portal we're checking