/*************************************************************************************************************
                                                   uC/GUI
                                               嵌入式通用圖形軟件
File        : GUI_DrawPolyline.c
Purpose     : Implementation of GUI_DrawPolyline (part of emWin GSC)
************************************************************************************************************/
#include <stddef.h>           /* needed for definition of NULL */
#include "GUI_Protected.H"

static void _DrawGraph(I16 *pay, int NumPoints, int xOff, int yOff) 
{
  int i;
  int y0, y1;
  int yClip0, yClip1;
  /* Perform high level clipping in x */
  yClip0 = GUI_Context.pClipRect_HL->y0;
  yClip1 = GUI_Context.pClipRect_HL->y1;
  i=0;
  if (GUI_Context.pClipRect_HL) 
  {
    if (xOff < GUI_Context.pClipRect_HL->x0)
      i = GUI_Context.pClipRect_HL->x0 - xOff;
    if (xOff+NumPoints-1 > GUI_Context.pClipRect_HL->x1)
      NumPoints = GUI_Context.pClipRect_HL->x1 - xOff + 1;
  }
  /* Start drawing if there is something left to do after x-clipping */
  if (i < NumPoints) 
  {
    y0 = *(pay + i++) + yOff;
    /* Iterate */
    for (; i < NumPoints; i++) 
    {
      /* Perform high level clipping in y */
      y1 = *(pay + i) + yOff;
      if ((y0 >= yClip0) | (y1 >= yClip0)) 
      {
        if ((y0 <= yClip1) | (y1 <= yClip1)) 
        {
          int y01;
          y01 = (y1 + y0) / 2;
          if (y0 <= y1) 
          {
            LCD_DrawVLine(i + xOff - 1, y0, y01);
            LCD_DrawVLine(i + xOff, y01, y1);
          } 
          else 
          {
            LCD_DrawVLine(i + xOff - 1, y01, y0);
            LCD_DrawVLine(i + xOff, y1, y01);
          }
        }
      }
      y0 = y1;
    }
  }
}
  
void GUI_DrawGraph(I16 *pay, int NumPoints, int x0, int y0) 
{
  GUI_LOCK();
  #if (GUI_WINSUPPORT)
    WM_ADDORG(x0,y0);
    WM_ITERATE_START(NULL); 
    {
  #endif
  _DrawGraph(pay, NumPoints, x0, y0);
  #if (GUI_WINSUPPORT)
    } WM_ITERATE_END();
  #endif
  GUI_UNLOCK();
}