guiaacircle.c

在ucos上实现了图形用户接口GUI；值得一看

/*
*********************************************************************************************************
*                                                uC/GUI
*                        Universal graphic software for embedded applications
*
*                       (c) Copyright 2002, Micrium Inc., Weston, FL
*                       (c) Copyright 2002, SEGGER Microcontroller Systeme GmbH
*
*              礐/GUI is protected by international copyright laws. Knowledge of the
*              source code may not be used to write a similar product. This file may
*              only be used in accordance with a license and should not be redistributed
*              in any way. We appreciate your understanding and fairness.
*
----------------------------------------------------------------------
File        : GUICirleAA.C
Purpose     : Draw Circle routines with Antialiasing

TBD: Circle needs to be calculated from top to bottom in order
to avoid AA problems at certain positions.  
    
---------------------------END-OF-HEADER------------------------------
*/

#include "GUI_Protected.H"

#include <stdio.h>
#include <string.h>
#include <math.h>

/*********************************************************************
*
*       Static code
*
**********************************************************************
*/
static void FillCircle       (int x0, int y0, int r) {
  int i, x;
  int sqmax = r*r+r/2;
  int yMin, yMax;
  /* First step : find uppermost and lowermost coordinates */
  yMin = y0 - r;
  yMax = y0 + r;
  /* Use Clipping rect to reduce calculation (if possible) */
  if (GUI_Context.pClipRect_HL) {
    if (yMax > GUI_Context.pClipRect_HL->y1)
      yMax = GUI_Context.pClipRect_HL->y1;
    if (yMin < GUI_Context.pClipRect_HL->y0)
      yMin = GUI_Context.pClipRect_HL->y0;
  }
  /* Draw top half */
  for (i=0, x=r; i<r; i++) {
    int y = y0-i;
    if ((y >= yMin) && (y <= yMax)) {
      /* calc proper x-value */
      while ((i*i+x*x) >sqmax)
        --x;
      LCD_HL_DrawHLine (x0-x, y, x0+x);
    }
  }
  /* Draw bottom half */
  for (i=0, x=r; i<r; i++) {
    int y = y0 + i;
    if ((y >= yMin) && (y <= yMax)) {
      /* calc proper x-value */
      while ((i*i+x*x) >sqmax)
        --x;
      LCD_HL_DrawHLine (x0-x, y, x0+x);
    }
  }
}

/*********************************************************************
*
*                       GL_FillCircleAA_HiRes
*
**********************************************************************
*/

void GL_FillCircleAA_HiRes  (int x0, int y0, int r) {
/* Init AA Subsystem, pass horizontal limits */
  GUI_AA_Init_HiRes(x0-r, x0+r);
/* Do the actual drawing */
  FillCircle(x0, y0, r);
/* Cleanup */
  GUI_AA_Exit();
}

/*********************************************************************
*
*                       GL_FillCircleAA
*
**********************************************************************
*/


void GUI_AA_FillCircle(int x0, int y0, int r) {
  #if (GUI_WINSUPPORT)
    GUI_RECT Rect;
  #endif
  if (!GUI_Context.AA_HiResEnable) {
    x0 *= GUI_Context.AA_Factor;
    y0 *= GUI_Context.AA_Factor;
    r  *= GUI_Context.AA_Factor;
  }
  GUI_LOCK();
  #if (GUI_WINSUPPORT)
    WM_ADDORG(x0,y0);
    Rect.x0 = GUI_AA_HiRes2Pixel(x0 - r);
    Rect.x1 = GUI_AA_HiRes2Pixel(x0 + r);
    Rect.y0 = GUI_AA_HiRes2Pixel(y0 - r);
    Rect.y1 = GUI_AA_HiRes2Pixel(y0 + r);
    WM_ITERATE_START(&Rect); {
  #endif
  GL_FillCircleAA_HiRes(x0, y0, r);
  #if (GUI_WINSUPPORT)
    } WM_ITERATE_END();
  #endif
  GUI_UNLOCK();
}