# view_moves.ludic - moving the view: zoom in steps or about a point (so what is under the pointer
# stays under it), a drag that pans, and a press that picks the mark under it

export function minimap_zoom_set(minimap_st: mut MinimapState, z: float) -> void {
  minimap_st.mm_zoom = Math.clamp(z, minimap_st.mm_zoom_min, minimap_st.mm_zoom_max)
  minimap_clamp(minimap_st)
}

# a step in (dir > 0) or out, a third at a time
export function minimap_zoom_step(minimap_st: mut MinimapState, dir: int) -> void {
  if dir > 0 { minimap_zoom_set(minimap_st, minimap_st.mm_zoom * 1.3) } else { minimap_zoom_set(minimap_st, minimap_st.mm_zoom / 1.3) }
}

# zoom by `factor` about a point of the window
export function minimap_zoom_about(minimap_st: mut MinimapState, rx: float, ry: float, factor: float) -> void {
  let wx = minimap_wx(minimap_st, rx)
  let wz = minimap_wz(minimap_st, ry)
  minimap_st.mm_zoom = Math.clamp(minimap_st.mm_zoom * factor, minimap_st.mm_zoom_min, minimap_st.mm_zoom_max)
  minimap_st.mm_vx = minimap_st.mm_vx + wx - minimap_wx(minimap_st, rx)
  minimap_st.mm_vz = minimap_st.mm_vz + wz - minimap_wz(minimap_st, ry)
  minimap_clamp(minimap_st)
}

export function minimap_pan_begin(minimap_st: mut MinimapState, rx: float, ry: float) -> void {
  minimap_st.mm_panning = true
  minimap_st.mm_drag_rx = rx
  minimap_st.mm_drag_ry = ry
  minimap_st.mm_drag_vx = minimap_st.mm_vx
  minimap_st.mm_drag_vz = minimap_st.mm_vz
}

# the point pressed follows the pointer
export function minimap_pan_to(minimap_st: mut MinimapState, rx: float, ry: float) -> void {
  if not minimap_st.mm_panning { return }
  minimap_st.mm_vx = minimap_st.mm_drag_vx - (rx - minimap_st.mm_drag_rx) / minimap_scale(minimap_st)
  minimap_st.mm_vz = minimap_st.mm_drag_vz - (ry - minimap_st.mm_drag_ry) / minimap_scale(minimap_st)
  minimap_clamp(minimap_st)
}

export function minimap_pan_end(minimap_st: mut MinimapState) -> void { minimap_st.mm_panning = false }
export function minimap_panning(minimap_st: MinimapState) -> bool { return minimap_st.mm_panning }

# the mark within r pixels of a point of the window is opened (the last drawn, so the top one);
# -1 and nothing changes when there is none
export function minimap_pick(minimap_st: mut MinimapState, rx: float, ry: float, r: float) -> int {
  let sx = minimap_st.mm_x0 + rx
  let sy = minimap_st.mm_y0 + ry
  var hit = -1
  for i in 0 .. minimap_pin_count(minimap_st) {
    let px = minimap_px(minimap_st, minimap_st.mm_pins[i].x)
    let py = minimap_py(minimap_st, minimap_st.mm_pins[i].z)
    if sx >= px - r and sx < px + r and sy >= py - r and sy < py + r { hit = i }
  }
  if hit >= 0 { minimap_st.mm_open = hit }
  return hit
}