Function d3d_DrawPolygon

legacy/renderer/Direct3D.cpp:2173–2338

Takes nv vertices anddraws the polygon defined by those vertices. Uses bitmap "handle" as a texture

// Takes nv vertices anddraws the polygon defined by those vertices.  Uses bitmap "handle"
// as a texture
void d3d_DrawPolygon(int handle, g3Point **p, int nv, int map_type) {
  HRESULT ddrval;
  TextureVertex *tvert_ptr;
  int i;

  if (d3d_CanBumpmap && Bumpmap_ready) {
    ASSERT(Overlay_type == OT_NONE);

    if (!d3d_DrawBumpmappedPolygon(p, nv, handle)) {
      mprintf(0, "error in d3d_DrawBumpmappedPolygon\n");
    }

    rend_SetBumpmapReadyState(0, 0);

    return;
  }

  if (d3d_CanBumpmap && D3D_bumpmap_state)
    d3d_SetBumpmappingBlendModes(0);

  if ((!D3D_state.cur_texture_quality)) {
    if (D3D_state.cur_alpha_type == AT_SPECULAR) {
      if (!d3d_MakeBitmapCurrent(handle, map_type, 0))
        return;
    }

    if (d3d_MultiTexture) // If this device can do multitexture, clear it so it won't
      d3d_SetMultiTextureBlendMode(false);

    d3d_DrawFlatPolygon(p, nv);

    return;
  }

  // Figure out subpixel correction for UVs
  if (d3d_SubpixelCorrect) {
    if (map_type == MAP_TYPE_BITMAP) {
      UV_diff = (1.0 / (float)bm_w(handle, 0)) / 2.0;
    } else if (map_type == MAP_TYPE_LIGHTMAP) {
      UV_diff = (1.0 / (float)lm_w(handle)) / 2.0;
    } else
      UV_diff = 0;
  } else
    UV_diff = 0;

  if (Overlay_type != OT_NONE && d3d_MultiTexture) {
    d3d_DrawMultiTexturePolygon(p, nv, handle, map_type);

    return;
  }

  int alpha = Alpha_multiplier * d3d_Alpha_factor;

  for (i = 0; i < nv; i++) {
    int r, g, b;

    g3Point *pnt = p[i];
    tvert_ptr = &TVerts[i];