Function g3_DrawPlanarRotatedBitmap

renderer/HardwareDraw.cpp:354–410

Draws a bitmap on a specific plane. Also does rotation. Angle of rotation is passed as 'rot_angle'

// Draws a bitmap on a specific plane.  Also does rotation.  Angle of rotation is passed as 'rot_angle'
void g3_DrawPlanarRotatedBitmap(vector *pos, vector *norm, angle rot_angle, float width, float height, int bm) {
  matrix rot_matrix;
  vm_VectorToMatrix(&rot_matrix, norm, NULL, NULL);
  vm_TransposeMatrix(&rot_matrix);

  matrix twist_matrix;
  vm_AnglesToMatrix(&twist_matrix, 0, 0, rot_angle);

  float w = width;
  float h = height;

  vector rot_vectors[4];
  rot_vectors[0] = (twist_matrix.rvec * -w);
  rot_vectors[0] += (twist_matrix.uvec * h);

  rot_vectors[1] = (twist_matrix.rvec * w);
  rot_vectors[1] += (twist_matrix.uvec * h);

  rot_vectors[2] = (twist_matrix.rvec * w);
  rot_vectors[2] -= (twist_matrix.uvec * h);

  rot_vectors[3] = (twist_matrix.rvec * -w);
  rot_vectors[3] -= (twist_matrix.uvec * h);

  int i;
  for (i = 0; i < 4; ++i) {
    vector temp_vec = rot_vectors[i];
    vm_MatrixMulVector(&rot_vectors[i], &temp_vec, &rot_matrix);
  }

  g3Point rot_points[8], *pntlist[8];
  for (i = 0; i < 4; ++i) {
    rot_vectors[i] += *pos;

    g3_RotatePoint(&rot_points[i], &rot_vectors[i]);
    rot_points[i].p3_flags |= PF_UV | PF_L;
    rot_points[i].p3_l = 1.0f;

    pntlist[i] = &rot_points[i];
  }

  rot_points[0].p3_u = 0.0f;
  rot_points[0].p3_v = 0.0f;

  rot_points[1].p3_u = 1.0f;
  rot_points[1].p3_v = 0.0f;

  rot_points[2].p3_u = 1.0f;
  rot_points[2].p3_v = 1.0f;

  rot_points[3].p3_u = 0.0f;
  rot_points[3].p3_v = 1.0f;

  // And draw!!
  rend_SetTextureType(TT_LINEAR);
  g3_DrawPoly(4, pntlist, bm);
}