SD卡Fatfs文件系统BMP文件读取显示

C语言: Codee#20097

#include "TFCard_BMP.h"
/*==================================================================
                        用到的变量及宏定义
==================================================================*/
BMP_HEAD  bmp;   //图片文件头
BMP_POINT point;

/*==================================================================
* Function    : RGB888ToRGB565
* Description    : 把24位图变成16位图
* Input Para    : unsigned char r , unsigned char g , unsigned char b
* Output Para    : void
* Return Value: 颜色值
==================================================================*/ 
u32 RGB888ToRGB565(unsigned char r , unsigned char g , unsigned char b)
{
    return (u32) (r & 0xF8) << 8 | (g & 0xFC) << 3 | (b & 0xF8) >> 3;
}

/*==================================================================
* Function    : DrawPixel
* Description    : 画点函数，在TFT的某一点上画一个颜色点
* Input Para    : unsigned int x , unsigned int y , int Color  ===》 x坐标，y坐标，颜色值
* Output Para    : void
* Return Value: void
==================================================================*/ 
void DrawPixel(unsigned int x , unsigned int y , int Color)
{
    LCD_SetGramPoint(x,y);
    LCD_WR_Data(Color);        
}

/*==================================================================
* Function    : Show_BMP
* Description    : 显示BMP格式的文件，分为图片和图标，图片尺寸是240*320是完全显示，图标只显示内容，其他白色的部分维持原来的颜色
* Input Para    : unsigned char type , unsigned int point_x , unsigned int point_y , char *path
         ===》   显示的类型：PCITURE图片，ICON图标 ，x轴起始点 ，y轴起始点 ，图片在SD卡里的路径
* Output Para    : void
* Return Value: void
==================================================================*/ 
void Show_BMP( unsigned char type , unsigned int point_x , unsigned int point_y ,char *path )
{
    FATFS fs;            // 磁盘挂载点
    FIL  fil;           // 文件打开点          
    FRESULT res;        // 返回值类型结构体

    //unsigned char buffer[4096*4];  // file copy buffer
    unsigned char buffer[50000];     // 这个数组和堆栈空间大小直接相关

    unsigned int  br;                // File R/W count
    unsigned long tx,ty,r_data,g_data,b_data;

    disk_initialize(0);                                                  // 初始化磁盘
    res = f_mount(0,&fs);                                              // 挂载设备
    while(1)
    {
        res = f_open(&fil , path , FA_OPEN_EXISTING | FA_READ);          // 读取图标路径
        res = f_read(&fil , &bmp , sizeof(bmp),&br);                   // 读取文件
        if((bmp.pic_head[0]=='B')&&(bmp.pic_head[1]=='M'))              // 判断是不是BMP文件
        {
            res = f_lseek(&fil ,((bmp.pic_data_address_h<<16)|bmp.pic_data_address_l)); // 采用了Windows的BMP格式，BMP原点在左下角
            for(ty=0;ty             {
                res = f_read(&fil , buffer , (bmp.pic_w_l)*3 , &br) ;
                for(tx=0;tx                 {
                    r_data = *(tx*3 +2+buffer);       
                    g_data = *(tx*3 +1+buffer);         
                    b_data = *(tx*3 +0+buffer);
                    if(tx<240)
                    {
                        point.x = tx;
                        point.y = bmp.pic_h_l -1 -ty;
                        point.r = r_data;
                        point.g = g_data;
                        point.b = b_data;
                        if(type == PICTURE)             // 如果显示的是图片的话，白色部分照常显示
                        {
                            DrawPixel(point.x + point_x,point.y +point_y,RGB888ToRGB565(point.r,point.g,point.b));
                        }
                        else if(type == ICON)         // 如果显示的是图标的话，白色部分不显示
                        {                             // 以下代码根据  DrawPixel() 函数更改增加
                            LCD_SetGramPoint( point.x+point_x , point.y+point_y);     // 设定x轴，y轴的坐标   
                            if(RGB888ToRGB565(point.r,point.g,point.b) ==0xFFFF)       // 判断是不是白色部分                       
                            {
                                LCD_WR_Data( ili9320_BGR2RGB(LCD_RD_data()) );            // 如果是白色就读取当前颜色值并显示
                            }
                            else
                            {
                                LCD_WR_Data( RGB888ToRGB565(point.r,point.g,point.b) );    // 如果不是白色就显示ICON的颜色
                            }
                        
                        }
                        
                    }
                }
            }
            f_close(&fil);                                              // 关闭文件
            f_mount(0,NULL);                                          // 卸载设备
            break;                                                      // 跳出while(1)
        }    // End of if((bmp.pic_head....
    }       // End of while(1)....
}            // End of void Show_BMP(....