1.畫點(diǎn)

我們首先實(shí)現(xiàn)畫點(diǎn)的函數(shù)，

#include "lcd.h"

/* 實(shí)現(xiàn)畫點(diǎn) */

/* 獲得LCD參數(shù) */

static unsigned int fb_base;

static int xres, yres, bpp;

void fb_get_lcd_params(void)

{

get_lcd_params(&fb_base, &xres, &yres, &bpp);

}

/* rgb: 0x00RRGGBB */

unsigned short convert32bppto16bpp(unsigned int rgb)

{

int r = (rgb >> 16)& 0xff;

int g = (rgb >> 8) & 0xff;

int b = rgb & 0xff;

/* rgb565 */

r = r >> 3;

g = g >> 2;

b = b >> 3;

return ((r<<11) | (g<<5) | (b));

}

/* color : 32bit, 0x00RRGGBB

 *

 */

void fb_put_pixel(int x, int y, unsigned int color)

{

unsigned char  *pc;  /* 8bpp */

unsigned short *pw;  /* 16bpp */

unsigned int   *pdw; /* 32bpp */

unsigned int pixel_base = fb_base + (xres * bpp / 8) * y + x * bpp / 8;

switch (bpp)

{

case 8:

pc = (unsigned char *) pixel_base;

*pc = color;

break;

case 16:

pw = (unsigned short *) pixel_base;

*pw = convert32bppto16bpp(color);

break;

case 32:

pdw = (unsigned int *) pixel_base;

*pdw = color;

break;

}

}

2.畫線、圓

畫線和畫圓的函數(shù)我們沒必要自己寫，直接從網(wǎng)上找，然后把里面的畫點(diǎn)函數(shù)替換成我們的即可。

#include "framebuffer.h"

/*

 * http://blog.csdn.net/p1126500468/article/details/50428613

 */

 //-------------畫圓函數(shù)。參數(shù)：圓心，半徑，顏色----------

 //    畫1/8圓 然后其他7/8對(duì)稱畫  

 // ---------------->X  

 // |(0,0)   0  

 // |    7 1

 // |   6   2  

 // |    5 3

 //   (Y)V   4  

 //  

 // L = x^2 + y^2 - r^2  

 void draw_circle(int x, int y, int r, int color)  

 {

int a, b, num;  

a = 0;  

b = r;  

while(22 * b * b >= r * r) // 1/8圓即可  

{

fb_put_pixel(x + a, y - b,color); // 0~1  

fb_put_pixel(x - a, y - b,color); // 0~7  

fb_put_pixel(x - a, y + b,color); // 4~5  

fb_put_pixel(x + a, y + b,color); // 4~3  

fb_put_pixel(x + b, y + a,color); // 2~3  

fb_put_pixel(x + b, y - a,color); // 2~1  

fb_put_pixel(x - b, y - a,color); // 6~7  

fb_put_pixel(x - b, y + a,color); // 6~5  

a++;  

num = (a * a + b * b) - r*r;  

if(num > 0)  

{

b--;  

a--;  

}

}

 }

 //-----------畫線。參數(shù)：起始坐標(biāo)，終點(diǎn)坐標(biāo)，顏色--------

 void draw_line(int x1,int y1,int x2,int y2,int color)

 {

int dx,dy,e;  

dx=x2-x1;  

dy=y2-y1;

if(dx>=0)

{

if(dy >= 0) // dy>=0  

{

if(dx>=dy) // 1/8 octant  

{

e=dy-dx/2;  

while(x1<=x2)

{

fb_put_pixel(x1,y1,color);  

if(e>0){y1+=1;e-=dx;}    

x1+=1;  

e+=dy;  

}

}

else // 2/8 octant

{

e=dx-dy/2;  

while(y1<=y2)

{

fb_put_pixel(x1,y1,color);  

if(e>0){x1+=1;e-=dy;}    

y1+=1;  

e+=dx;  

}

}

}

else // dy<0  

{

dy=-dy;   // dy=abs(dy)  

if(dx>=dy) // 8/8 octant  

{

e=dy-dx/2;  

while(x1<=x2)

{

fb_put_pixel(x1,y1,color);  

if(e>0){y1-=1;e-=dx;}    

x1+=1;  

e+=dy;  

}

}

else // 7/8 octant

{

e=dx-dy/2;  

while(y1>=y2)

{

fb_put_pixel(x1,y1,color);  

if(e>0){x1+=1;e-=dy;}    

y1-=1;  

e+=dx;  

}

}

}    

}

else //dx<0  

{

dx=-dx; //dx=abs(dx)  

if(dy >= 0) // dy>=0  

{

if(dx>=dy) // 4/8 octant  

{

e=dy-dx/2;  

while(x1>=x2)

{

fb_put_pixel(x1,y1,color);  

if(e>0){y1+=1;e-=dx;}    

x1-=1;  

e+=dy;  

}

}

else // 3/8 octant

{

e=dx-dy/2;  

while(y1<=y2)

{

fb_put_pixel(x1,y1,color);  

if(e>0){x1-=1;e-=dy;}    

y1+=1;  

e+=dx;  

}

}

}

else // dy<0  

{

dy=-dy;   // dy=abs(dy)  

if(dx>=dy) // 5/8 octant  

{

e=dy-dx/2;  

while(x1>=x2)

{

fb_put_pixel(x1,y1,color);  

if(e>0){y1-=1;e-=dx;}    

x1-=1;  

e+=dy;  

}

}

else // 6/8 octant

{

e=dx-dy/2;  

while(y1>=y2)

{

fb_put_pixel(x1,y1,color);  

if(e>0){x1-=1;e-=dy;}    

y1-=1;  

e+=dx;  

}

}

}    

}

 }

3.lcd_test.c

#include "geometry.h"

void lcd_test(void)

{

unsigned int fb_base;

int xres, yres, bpp;

int x, y;

unsigned short *p;

unsigned int *p2;

/* 初始化LCD */

lcd_init();

/* 使能LCD */

lcd_enable();

/* 獲得LCD的參數(shù): fb_base, xres, yres, bpp */

get_lcd_params(&fb_base, &xres, &yres, &bpp);

fb_get_lcd_params();

/* 往framebuffer中寫數(shù)據(jù) */

if (bpp == 16)

{

/* 讓LCD輸出整屏的紅色 */

/* 565: 0xf800 */

p = (unsigned short *)fb_base;

for (x = 0; x < xres; x++)

for (y = 0; y < yres; y++)

*p++ = 0xf800;

/* green */

p = (unsigned short *)fb_base;

for (x = 0; x < xres; x++)

for (y = 0; y < yres; y++)

*p++ = 0x7e0;

/* blue */

p = (unsigned short *)fb_base;

for (x = 0; x < xres; x++)

for (y = 0; y < yres; y++)

*p++ = 0x1f;

/* black */

p = (unsigned short *)fb_base;

for (x = 0; x < xres; x++)

for (y = 0; y < yres; y++)

*p++ = 0;

}

else if (bpp == 32)

{

/* 讓LCD輸出整屏的紅色 */

/* 0xRRGGBB */

p2 = (unsigned int *)fb_base;

for (x = 0; x < xres; x++)

for (y = 0; y < yres; y++)

*p2++ = 0xff0000;

/* green */

p2 = (unsigned int *)fb_base;

for (x = 0; x < xres; x++)

for (y = 0; y < yres; y++)

*p2++ = 0x00ff00;

/* blue */

p2 = (unsigned int *)fb_base;

for (x = 0; x < xres; x++)

for (y = 0; y < yres; y++)

*p2++ = 0x0000ff;

/* black */

p2 = (unsigned int *)fb_base;

for (x = 0; x < xres; x++)

for (y = 0; y < yres; y++)

*p2++ = 0;

}

delay(1000000);

/* 畫線 */

draw_line(0, 0, xres - 1, 0, 0xff0000);

draw_line(xres - 1, 0, xres - 1, yres - 1, 0xffff00);

draw_line(0, yres - 1, xres - 1, yres - 1, 0xff00aa);

draw_line(0, 0, 0, yres - 1, 0xff00ef);

draw_line(0, 0, xres - 1, yres - 1, 0xff4500);

draw_line(xres - 1, 0, 0, yres - 1, 0xff0780);

delay(1000000);

/* 畫圓 */

draw_circle(xres/2, yres/2, yres/4, 0xff00);

}