Function DrawThrusterEffect

model/newstyle.cpp:624–674

Draws a glowing cone of light that represents thrusters

// Draws a glowing cone of light that represents thrusters
void DrawThrusterEffect(vector *pos, float r, float g, float b, vector *norm, float size, float length) {
  vector cur_pos = *pos;
  float cur_length = 0;
  vector glow_pos[MAX_PARTS];
  float glow_size[MAX_PARTS];
  int total_parts = 0;

  if (length < .1)
    return;

  int num_divs = length * 3;
  if (num_divs > MAX_PARTS)
    num_divs = MAX_PARTS;

  float size_change = size / num_divs;
  float pos_change = length / num_divs;

  if (!UseHardware)
    return; // No software stuff here!

  rend_SetZBufferWriteMask(0);
  rend_SetAlphaType(AT_SATURATE_TEXTURE);
  rend_SetAlphaValue(.3 * 255);

  rend_SetLighting(LS_GOURAUD);
  rend_SetColorModel(CM_RGB);

  ddgr_color color = GR_RGB(r * 255, g * 255, b * 255);
  int bm_handle = Fireballs[GRADIENT_BALL_INDEX].bm_handle;
  int t;

  // We must draw the small ones first, but we're starting the iteration from the
  // large one.  Consequently, we must store our variables so we can draw in reverse order
  for (t = 0; t < num_divs && size > .05; t++) {
    glow_pos[t] = cur_pos;
    glow_size[t] = size;

    size -= size_change;
    cur_pos += ((*norm) * pos_change);

    total_parts++;
  }

  for (t = total_parts - 1; t >= 0; t--) {
    rend_SetZBias(-glow_size[t]);
    g3_DrawBitmap(&glow_pos[t], glow_size[t], (glow_size[t] * bm_h(bm_handle, 0)) / bm_w(bm_handle, 0), bm_handle,
                  color);
  }
  rend_SetZBias(0.0);
  rend_SetZBufferWriteMask(1);
}

// Draws a glowing cone of light
void DrawGlowEffect(vector *pos, float r, float g, float b, vector *norm, float size) {