www.pudn.com > ucosv2(GUI).rar > guiarc.c

/*
*********************************************************************************************************
*                                                uC/GUI
*                        Universal graphic software for embedded applications
*
*                       (c) Copyright 2002, Micrium Inc., Weston, FL
*                       (c) Copyright 2002, SEGGER Microcontroller Systeme GmbH
*
*              µC/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        : GUIARCFloat.C 
Purpose     : Draw Arc routines based on floating point 
---------------------------------------------------------------------- 
Version-Date---Author-Explanation 
---------------------------------------------------------------------- 
2.00.00 000325 RS     First release of the new algorithm 
---------------------------------------------------------------------- 
Known problems or limitations with current version 
---------------------------------------------------------------------- 
None. 
---------------------------------------------------------------------- 
Open issues 
---------------------------------------------------------------------- 
None 
---------------------------END-OF-HEADER------------------------------ 
*/ 
 
#include            /* needed for definition of NULL */ 
#include  
#include "GUI_Private.h" 
 
 
 
static void CalcX(int*px, int y, U32 r2) { 
  int x =*px; 
  U32 y2 = (U32)y*(U32)y; 
  U32 r2y2 = r2-y2; 
  U32 x2; 
  if (y2>=r2) { 
    *px=0; 
		return; 
	} 
  /* x2 = r2-y2 */ 
  do { 
    x++; 
    x2 =(U32)x*(U32)x; 
	} while (x2 < r2y2); 
	*px = x-1; 
} 
 
static float CalcInterSectLin(float y, float y0, float y1, float x0, float x1) { 
  if (y1==y0) { 
	  return y0; 
	} else { 
    float Slope = (x1-x0)/(y1-y0); 
   return (y-y0)*Slope+x0; 
	} 
} 
 
static void _DrawArc(int x0, int y0, int rx, int ry, int Angle0, int Angle1, int xMul, int yMul) { 
  float afx[4]; 
  float afy[4]; 
	float ri = rx-(GUI_Context.PenSize+1.5)/2; 
	float ro = rx+(GUI_Context.PenSize+1.5)/2; 
  float fAngle0 = Angle0*3.1415926/180; 
  float fAngle1 = Angle1*3.1415926/180; 
  float sin0 = sin(fAngle0);  
  float sin1 = sin(fAngle1);  
  float cos0 = cos(fAngle0);  
  float cos1 = cos(fAngle1);  
  U32   ri2 = ri*ri; 
  U32   ro2 = ro*ro; 
	int y, yMax, yMin; 
	afy[0] = ri*sin0; 
	afy[1] = ro*sin0; 
	afy[2] = ri*sin1; 
	afy[3] = ro*sin1; 
	afx[0] = ri*cos0; 
	afx[1] = ro*cos0; 
	afx[2] = ri*cos1; 
	afx[3] = ro*cos1; 
	yMin = ceil(afy[0]); 
  yMax = floor(afy[3]); 
  /* Use Clipping rect to reduce calculation (if possible) */ 
  if (GUI_Context.pClipRect_HL) { 
    if (yMul ==1) { 
      if (yMax > (GUI_Context.pClipRect_HL->y1 -y0)) 
        yMax = (GUI_Context.pClipRect_HL->y1 -y0); 
      if (yMin < (GUI_Context.pClipRect_HL->y0 -y0)) 
        yMin = (GUI_Context.pClipRect_HL->y0 -y0); 
    } 
    if (yMul == -1) { 
      if (yMin > (GUI_Context.pClipRect_HL->y1 -y0)) 
        yMin = (GUI_Context.pClipRect_HL->y1 -y0); 
      if (yMax < (GUI_Context.pClipRect_HL->y0 -y0)) 
        yMax = (GUI_Context.pClipRect_HL->y0 -y0); 
    } 
  } 
  /* Start drawing lines ... */ 
  { 
  int xMinDisp, xMaxDisp, xMin=0,xMax=0; 
    for (y=yMax; y>=yMin; y--) { 
      CalcX(&xMin, y, ri2); 
      CalcX(&xMax, y, ro2); 
      if ((float)y< afy[1]) { 
        xMaxDisp = CalcInterSectLin(y,afy[0], afy[1], afx[0], afx[1]); 
			} else { 
        xMaxDisp = xMax;			 
			} 
      if ((float)y > afy[2]) { 
        xMinDisp = CalcInterSectLin(y,afy[2], afy[3], afx[2], afx[3]); 
			} else { 
        xMinDisp = xMin;			 
			} 
      if (xMul>0) 
        LCD_HL_DrawHLine(xMinDisp+x0, yMul*y+y0, xMaxDisp+x0); 
      else 
        LCD_HL_DrawHLine(-xMaxDisp+x0, yMul*y+y0, -xMinDisp+x0); 
    } 
	} 
#if 0  /* Test code */ 
{ 
  int i; 
  GUI_SetColor( GUI_WHITE );  
	for (i=0; i<4; i++) 
    LCD_HL_DrawPixel(afx[i]+x0, afy[i]+y0); 
} 
#endif 
  GUI_USE_PARA(ry); 
} 
 
void GL_DrawArc (int x0, int y0, int rx, int ry, int a0, int a1) { 
  int aEnd; 
  a0+=360; 
	a1+=360; 
	while (a0>=360) { 
    a0 -= 360; 
    a1 -= 360; 
	} 
/* Do first quadrant 0-90 degree */ 
DoFirst: 
  if (a1<=0) 
	  return; 
	if (a0<90) { 
    if (a0<0) 
		  a0=0; 
    aEnd = (a1<90) ? a1 : 90; 
    _DrawArc(x0,y0,rx,ry,a0,aEnd, 1, -1); 
	} 
  a1-=90; 
	a0-=90; 
/* Do second quadrant 90-180 degree */ 
  if (a1<=0) 
	  return; 
	if (a0<90) { 
    if (a0<0) 
		  a0=0; 
    aEnd = (a1<90) ? a1 : 90; 
    _DrawArc(x0,y0,rx,ry,90-aEnd, 90-a0,-1,-1); 
	} 
  a1-=90; 
	a0-=90; 
/* Do third quadrant 180-270 degree */ 
  if (a1<=0) 
	  return; 
	if (a0<90) { 
    if (a0<0) 
		  a0=0; 
    aEnd = (a1<90) ? a1 : 90; 
    _DrawArc(x0,y0,rx,ry,a0,aEnd, -1, 1); 
	} 
  a1-=90; 
	a0-=90; 
/* Do last quadrant 270-360 degree */ 
  if (a1<=0) 
	  return; 
	if (a0<90) { 
    if (a0<0) 
		  a0=0; 
    aEnd = (a1<90) ? a1 : 90; 
    _DrawArc(x0,y0,rx,ry,90-aEnd, 90-a0,1,1); 
	} 
  a1-=90; 
	a0-=90; 
goto DoFirst; 
} 
 
void GUI_DrawArc (int x0, int y0, int rx, int ry, int a0, int a1) { 
  GUI_LOCK(); 
  #if (GUI_WINSUPPORT) 
    WM_ADDORG(x0,y0); 
    WM_ITERATE_START(NULL) { 
  #endif 
  GL_DrawArc( x0, y0, rx, ry, a0, a1); 
  #if (GUI_WINSUPPORT) 
    } WM_ITERATE_END(); 
  #endif 
  GUI_UNLOCK(); 
}