基于ARM平台的钢琴游戏 08实现音乐钢琴效果

ID:222305 · 发表于 2017-7-25 15:41

//////////////////////////////////////////////////////////////////
//
//  Copyright(C), 2013-2016, GEC Tech. Co., Ltd.
//
//  File name: GPLE/bmp.c
//
//  Author: Vincent Lin (林世霖)  微信公众号：秘籍酷
//
//  Date: 2016-11
//
//  Description: 处理BMP格式图像数据
//
//  GitHub: github.com/vincent040 Bug Report: 2437231462@qq.com
//
//////////////////////////////////////////////////////////////////

#include <errno.h>
#include "bmp.h"
#include "ts.h"

char * load_bmp(const char *bmpfile, struct image_info *minfo)
{
      int fd = open(bmpfile, O_RDONLY);
      if(fd == -1)
      {
            fprintf(stderr, "opening \"%s\" failed: %s\n",
                                    bmpfile, strerror(errno));
            exit(0);
      }

      // 获得文件大小，并分配内存
      struct stat fileinfo;
      fstat(fd, &fileinfo);

      int rgb_size = fileinfo.st_size;
      char *rgb_buf  = calloc(1, rgb_size);

      // 读取BMP内容到内存中
      struct bitmap_header header;
      struct bitmap_info info;
      struct rgb_quad quad;
      read(fd, &header, sizeof(header));
      read(fd, &info, sizeof(info));
      if(info.compression != 0)
      {
            read(fd, &quad, sizeof(quad));
            fprintf(stderr, "read quad! \n");
      }
      read(fd, rgb_buf, rgb_size);

      minfo->width = info.width;
      minfo->height= info.height;
      minfo->pixel_size = info.bit_count/8;

      #ifdef DEBUG
      printf("width: %d\n", minfo->width);
      printf("height: %d\n", minfo->height);
      printf("pixel_size: %d\n", minfo->pixel_size);
      #endif

      close(fd);
      return rgb_buf;
}

void bmp2lcd(char *bmpfile, char *FB,
                     struct fb_var_screeninfo *vinfo,
                     int xoffset, int yoffset)
{
      xoffset = xoffset>(65*12+10) ? (65*10+10) : xoffset;

      struct image_info *minfo = calloc(1, sizeof(struct image_info));
      char *rgb_buf = load_bmp(bmpfile, minfo);
      char *tmp = rgb_buf;

      // 从最后一行开始显示BMP图像
      int pad = ((4-( minfo->width * minfo->pixel_size ) % 4)) % 4; // 0-3
      rgb_buf += (minfo->width * minfo->pixel_size + pad) * (minfo->height-1);

      FB += (yoffset * vinfo->xres + xoffset) * 4;
      int lcd_w = vinfo->xres - xoffset;
      int lcd_h = vinfo->yres - yoffset;

      int x, y;
      for(x=0; x<lcd_h && x<minfo->height; x++)
      {
            for(y=0; y<lcd_w && y<minfo->width; y++)
            {
                     unsigned long lcd_offset = (vinfo->xres*x + y) * 4;
                     rgb_buf += minfo->pixel_size;

                     memcpy(FB + lcd_offset + vinfo->red.offset/8, rgb_buf + 2, 1);
                     memcpy(FB + lcd_offset + vinfo->green.offset/8, rgb_buf + 1, 1);
                     memcpy(FB + lcd_offset + vinfo->blue.offset/8,  rgb_buf + 0, 1);
            }

            rgb_buf += pad;
            rgb_buf -= (minfo->width * minfo->pixel_size + pad) * 2;
      }

      free(tmp);
}

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