57、编写lcd画点、划线、画圆、点阵
1、framebuffer.c 实现画点的函数
#include "lcd.h"
/* 实现画点 */
/* 获得LCD参数 */
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、geometry.c 实现划线和画圆的函数
#include "framebuffer.h"
/*
* http://blog.csdn.net/p1126500468/article/details/50428613
*/
//-------------画圆函数。参数：圆心，半径，颜色----------
// 画1/8圆 然后其他7/8对称画
// ---------------->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圆即可
{
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--;
}
}
}
//-----------画线。参数：起始坐标，终点坐标，颜色--------
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、font_8x16.c点阵
const unsigned char fontdata_8x16[FONTDATAMAX] = {
/* 0 0x00 '^@' */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
/* 1 0x01 '^A' */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x7e, /* 01111110 */
0x81, /* 10000001 */
0xa5, /* 10100101 */
0x81, /* 10000001 */
0x81, /* 10000001 */
0xbd, /* 10111101 */
0x99, /* 10011001 */
0x81, /* 10000001 */
0x81, /* 10000001 */
0x7e, /* 01111110 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
...
/* 255 0xff '' */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
0x00, /* 00000000 */
};
4、font.c 实现显示字符
extern const unsigned char fontdata_8x16[];
/* 获得LCD参数 */
static unsigned int fb_base;
static int xres, yres, bpp;
void font_init(void)
{
get_lcd_params(&fb_base, &xres, &yres, &bpp);
}
/* 根据字母的点阵在LCD上描画文字 */
void fb_print_char(int x, int y, char c, unsigned int color)
{
int i, j;
/* 根据c的ascii码在fontdata_8x16中得到点阵数据 */
unsigned char *dots = &fontdata_8x16[c * 16];
unsigned char data;
int bit;
/* 根据点阵来设置对应象素的颜色 */
for (j = y; j < y+16; j++)
{
data = *dots++;
bit = 7;
for (i = x; i < x+8; i++)
{
/* 根据点阵的某位决定是否描颜色 */
if (data & (1<
bit--;
}
}
}
/* "abc\n\r123" */
void fb_print_string(int x, int y, char* str, unsigned int color)
{
int i = 0, j;
while (str[i])
{
if (str[i] == '\n')
y = y+16;
else if (str[i] == '\r')
x = 0;
else
{
fb_print_char(x, y, str[i], color);
x = x+8;
if (x >= xres) /* 换行 */
{
x = 0;
y = y+16;
}
}
i++;
}
}
5、lcd_test.c 测试程序
#include "geometry.h"
#include "font.h"
void lcd_test(void)
{
unsigned int fb_base;
int xres, yres, bpp;
int x, y;
unsigned char *p0;
unsigned short *p;
unsigned int *p2;
/* 初始化LCD */
lcd_init();
/* 使能LCD */
lcd_enable();
/* 获得LCD的参数: fb_base, xres, yres, bpp */
get_lcd_params(&fb_base, &xres, &yres, &bpp);
fb_get_lcd_params();
font_init();
/* 往framebuffer中写数据 */
if (bpp == 8)
{
/* 让LCD输出整屏的红色 */
/* bpp: palette[12] */
p0 = (unsigned char *)fb_base;
for (x = 0; x < xres; x++)
for (y = 0; y < yres; y++)
*p0++ = 12;
/* palette[47] */
p0 = (unsigned char *)fb_base;
for (x = 0; x < xres; x++)
for (y = 0; y < yres; y++)
*p0++ = 47;
/* palette[88] */
p0 = (unsigned char *)fb_base;
for (x = 0; x < xres; x++)
for (y = 0; y < yres; y++)
*p0++ = 88;
/* palette[0] */
p0 = (unsigned char *)fb_base;
for (x = 0; x < xres; x++)
for (y = 0; y < yres; y++)
*p0++ = 0;
}
else if (bpp == 16)
{
/* 让LCD输出整屏的红色 */
/* 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)
{
/* 让LCD输出整屏的红色 */
/* 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);
/* 画线 */
draw_line(0, 0, xres - 1, 0, 0x23ff77);
draw_line(xres - 1, 0, xres - 1, yres - 1, 0xffff);
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, 0xff45);
draw_line(xres - 1, 0, 0, yres - 1, 0xff0780);
delay(1000000);
/* 画圆 */
draw_circle(xres/2, yres/2, yres/4, 0xff);
/* 输出文字 */
fb_print_string(10, 10, "www.100ask.net\n\r100ask.taobao.com", 0xff);
}