/**
* Name : SDLColorToColor
*
* Change from an "SDL_Color" to an Uint32
* sdl_color input SDL_Color Color
* return Uint32 Color
*/
Uint32 SDLColorToColor(SDL_Color* sdl_color)
{
return SDL_MapRGB(screen->format, sdl_color->r, sdl_color->g, sdl_color->b);
}
/*
* Return the pixel value at (x, y) 获取像素
* NOTE: The surface must be locked before calling this!
*/
Uint32 get_pixel(SDL_Surface *surface, int x, int y)
{
int bpp = surface->format->BytesPerPixel;
/* Here p is the address to the pixel we want to retrieve */
Uint8 *p = (Uint8 *)surface->pixels + y * surface->pitch + x * bpp;
switch(bpp) {
case 1:
return *p;
case 2:
return *(Uint16 *)p;
case 3:
if(SDL_BYTEORDER == SDL_BIG_ENDIAN)
return p[0] << 16 | p[1] << 8 | p[2];
else
return p[0] | p[1] << 8 | p[2] << 16;
case 4:
return *(Uint32 *)p;
default:
return 0; /* shouldn't happen, but avoids warnings */
}
}
/*
* Set the pixel at (x, y) to the given value 设置像素
* NOTE: The surface must be locked before calling this!
*/
void put_pixel(SDL_Surface *surface, int x, int y, Uint32 pixel)
{
switch (surface->format->BytesPerPixel)
{
case 1: // Assuming 8-bpp
{
Uint8 *bufp;
bufp = (Uint8 *)surface->pixels + y*surface->pitch + x;
*bufp = pixel;
}
break;
case 2: // Probably 15-bpp or 16-bpp
{
Uint16 *bufp;
bufp = (Uint16 *)surface->pixels + y*surface->pitch/2 + x;
*bufp = pixel;
}
break;
case 3: // Slow 24-bpp mode, usually not used
{
Uint8 *bufp;
bufp = (Uint8 *)surface->pixels + y*surface->pitch + x * 3;
if(SDL_BYTEORDER == SDL_LIL_ENDIAN)
{
bufp[0] = pixel;
bufp[1] = pixel >> 8;
bufp[2] = pixel >> 16;
} else {
bufp[2] = pixel;
bufp[1] = pixel >> 8;
bufp[0] = pixel >> 16;
}
}
break;
case 4: // Probably 32-bpp
{
Uint32 *bufp;
bufp = (Uint32 *)surface->pixels + y*surface->pitch/4 + x;
*bufp = pixel;
}
break;
}
}
/**
* dda_line 画像素
*
* screen 屏幕指针
* x 点X
* y 点Y
* R 颜色R
* G 颜色G
* B 颜色B
*/
void put_pixel(SDL_Surface *screen, int x, int y, Uint8 R, Uint8 G, Uint8 B)
{
Uint32 color = SDL_MapRGB(screen->format, R, G, B);
switch (screen->format->BytesPerPixel)
{
case 1: // Assuming 8-bpp
{
Uint8 *bufp;
bufp = (Uint8 *)screen->pixels + y*screen->pitch + x;
*bufp = color;
}
break;
case 2: // Probably 15-bpp or 16-bpp
{
Uint16 *bufp;
bufp = (Uint16 *)screen->pixels + y*screen->pitch/2 + x;
*bufp = color;
}
break;
case 3: // Slow 24-bpp mode, usually not used
{
Uint8 *bufp;
bufp = (Uint8 *)screen->pixels + y*screen->pitch + x * 3;
if(SDL_BYTEORDER == SDL_LIL_ENDIAN)
{
bufp[0] = color;
bufp[1] = color >> 8;
bufp[2] = color >> 16;
} else {
bufp[2] = color;
bufp[1] = color >> 8;
bufp[0] = color >> 16;
}
}
break;
case 4: // Probably 32-bpp
{
Uint32 *bufp;
bufp = (Uint32 *)screen->pixels + y*screen->pitch/4 + x;
*bufp = color;
}
break;
}
}
/**
* draw point 画点
*/
void draw_point(SDL_Surface *screen,POINT p,Uint32 color)
{
int x,y;
//x = p.x-m_FaceInfo.headArea.left-1;
//y = p.y-m_FaceInfo.headArea.top-1;
x = p.x;
y = p.y;
if ( SDL_MUSTLOCK(screen) ) {
if ( SDL_LockSurface(screen) < 0 ) {
fprintf(stderr, "Can't lock screen: %s\n", SDL_GetError());
return;
}
}
put_pixel(screen, x, y, color);
if ( SDL_MUSTLOCK(screen) ) {
SDL_UnlockSurface(screen);
}
/* Update just the part of the display that we've changed */
SDL_UpdateRect(screen, x,y, 1, 1);
return;
}
/**
* draw bresenham line 画bresenham线
*/
void bresenham_line(SDL_Surface *screen,POINT start, POINT end, Uint32 c)
{
int x1, y1, x2, y2;
int dx,dy,x,y,p,const1,const2,inc,tmp;
x1 = start.x-m_FaceInfo.headArea.left-1;
y1 = start.y-m_FaceInfo.headArea.top-1;
x2 = end.x-m_FaceInfo.headArea.left-1;
y2 = end.y-m_FaceInfo.headArea.top-1;
dx = x2-x1;
dy = y2-y1;
if(dx*dy >= 0)
inc = 1;
else
inc = -1;
if(abs(dx)>abs(dy))
{
if(dx<0)
{
tmp = x1;
x1 = x2;
x2 = tmp;
tmp = y1;
y1 = y2;
y2 = tmp;
dx = -dx;
dy = -dy;
}
p = 2*dy-dx;
const1 = 2*dy;
const2 = 2*(dy-dx);
x = x1;
y = y1;
put_pixel(screen,x,y,c);
while(x<x2)
{
x++;
if(p<0)
p += const1;
else
{
y += inc;
p += const2;
}
put_pixel(screen,x,y,c);
}
}
else
{
if(dy<0)
{
tmp = x1;
x1 = x2;
x2 = tmp;
tmp = y1;
y1 = y2;
y2 = tmp;
dx = -dx;
dy = -dy;
}
p = 2*dy-dx;
const1 = 2*dy;
const2 = 2*(dy-dx);
x = x1;
y = y1;
put_pixel(screen,x,y,c);
while(y<y2)
{
y++;
if(p<0)
p += const1;
else
{
x+=inc;
p+=const2;
}
put_pixel(screen,x,y,c);
}
}
}
/**
* draw line 画bresenham线
*/
void bresenham_line(SDL_Surface *screen,int x1,int y1,int x2, int y2, Uint32 c)
{
int dx,dy,x,y,p,const1,const2,inc,tmp;
dx = x2-x1;
dy = y2-y1;
if(dx*dy >= 0)
inc = 1;
else
inc = -1;
if(abs(dx)>abs(dy))
{
if(dx<0)
{
tmp = x1;
x1 = x2;
x2 = tmp;
tmp = y1;
y1 = y2;
y2 = tmp;
dx = -dx;
dy = -dy;
}
p = 2*dy-dx;
const1 = 2*dy;
const2 = 2*(dy-dx);
x = x1;
y = y1;
put_pixel(screen,x,y,c);
while(x<x2)
{
x++;
if(p<0)
p += const1;
else
{
y += inc;
p += const2;
}
put_pixel(screen,x,y,c);
}
}
else
{
if(dy<0)
{
tmp = x1;
x1 = x2;
x2 = tmp;
tmp = y1;
y1 = y2;
y2 = tmp;
dx = -dx;
dy = -dy;
}
p = 2*dy-dx;
const1 = 2*dy;
const2 = 2*(dy-dx);
x = x1;
y = y1;
put_pixel(screen,x,y,c);
while(y<y2)
{
y++;
if(p<0)
p += const1;
else
{
x+=inc;
p+=const2;
}
put_pixel(screen,x,y,c);
}
}
}
/**
* dda_line 画线
*
* screen 屏幕指针
* start 开始点
* end 结束点
* c 颜色
*/
void dda_line(SDL_Surface *screen,POINT start, POINT end, Uint32 c)
{
int xa, ya, xb, yb;
float delta_x,delta_y,x,y;
int dx,dy,steps,k;
//xa = start.x-m_FaceInfo.headArea.left-1;
//ya = start.y-m_FaceInfo.headArea.top-1;
//xb = end.x-m_FaceInfo.headArea.left-1;
//yb = end.y-m_FaceInfo.headArea.top-1;
xa = start.x;
ya = start.y;
xb = end.x;
yb = end.y;
dx = xb-xa;
dy = yb-ya;
if(abs(dx)>abs(dy))
steps = abs(dx);
else
steps = abs(dy);
delta_x = (float)dx/(float)steps;
delta_y = (float)dy/(float)steps;
x = (float)xa;
y = (float)ya;
put_pixel(screen,x,y,c);
for(k = 0;k<steps;k++)
{
x+=delta_x;
y+=delta_y;
put_pixel(screen,x,y,c);
}
return ;
}
/**
* dda_line 画线
*
* screen 屏幕指针
* xa 开始点X
* ya 开始点Y
* xb 结束点X
* yb 结束点Y
* c 颜色
*/
void dda_line(SDL_Surface *screen,int xa,int ya,int xb,int yb,Uint32 c)
{
float delta_x,delta_y,x,y;
int dx,dy,steps,k;
dx = xb-xa;
dy = yb-ya;
if(abs(dx)>abs(dy))
steps = abs(dx);
else
steps = abs(dy);
delta_x = (float)dx/(float)steps;
delta_y = (float)dy/(float)steps;
x = xa;
y = ya;
put_pixel(screen,x,y,c);
for(k = 0;k<steps;k++)
{
x+=delta_x;
y+=delta_y;
put_pixel(screen,x,y,c);
}
return ;
}
/**
* dda_line 画像素
*
* screen 屏幕指针
* x 点X
* y 点Y
*/
void DrawPixel(SDL_Surface *screen, int x, int y, Uint32 color)
{
switch (screen->format->BytesPerPixel)
{
case 1: // Assuming 8-bpp
{
Uint8 *bufp;
bufp = (Uint8 *)screen->pixels + y*screen->pitch + x;
*bufp = color;
}
break;
case 2: // Probably 15-bpp or 16-bpp
{
Uint16 *bufp;
bufp = (Uint16 *)screen->pixels + y*screen->pitch/2 + x;
*bufp = color;
}
break;
case 3: // Slow 24-bpp mode, usually not used
{
Uint8 *bufp;
bufp = (Uint8 *)screen->pixels + y*screen->pitch + x * 3;
if(SDL_BYTEORDER == SDL_LIL_ENDIAN)
{
bufp[0] = color;
bufp[1] = color >> 8;
bufp[2] = color >> 16;
} else {
bufp[2] = color;
bufp[1] = color >> 8;
bufp[0] = color >> 16;
}
}
break;
case 4: // Probably 32-bpp
{
Uint32 *bufp;
bufp = (Uint32 *)screen->pixels + y*screen->pitch/4 + x;
*bufp = color;
}
break;
}
}
/**
* 画圆调用子方法
*
*/
void plot_circle_points(SDL_Surface *screen,int xc,int yc,int x,int y,Uint32 c)
{
put_pixel(screen,xc+x,yc+y,c);
put_pixel(screen,xc-x,yc+y,c);
put_pixel(screen,xc+x,yc-y,c);
put_pixel(screen,xc-x,yc-y,c);
put_pixel(screen,xc+y,yc+x,c);
put_pixel(screen,xc-y,yc+x,c);
put_pixel(screen,xc+y,yc-x,c);
put_pixel(screen,xc-y,yc-x,c);
}
/**
* 画圆
*
* screen 屏
* cp 圆中心点
* radius 半径
* c 颜色
*/
void bresenham_circle(SDL_Surface *screen,POINT cp,int radius,Uint32 c)
{
int xc, yc;
int x,y,p;
//xc = cp.x - m_FaceInfo.headArea.left-1;
//yc = cp.y - m_FaceInfo.headArea.top-1;
xc = cp.x;
yc = cp.y;
x = 0;
y = radius;
p = 3-2*radius;
while(x<y)
{
plot_circle_points(screen,xc,yc,x,y,c);
if(p<0)
p=p+4*x+6;
else
{
p=p+4*(x-y)+10;
y-=1;
}
x+=1;
}
if(x == y)
plot_circle_points(screen,xc,yc,x,y,c);
}
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