fb_var_screeninfo

说明

定义HIFB的可变屏幕信息，此为Linux FrameBuffer原生结构体。

定义

struct fb_var_screeninfo {
    __u32 xres;             /* visible resolution       */
    __u32 yres;
    __u32 xres_virtual;     /* virtual resolution       */
    __u32 yres_virtual;
    __u32 xoffset;          /* offset from virtual to visible */
    __u32 yoffset;          /* resolution           */
    __u32 bits_per_pixel;   
    __u32 grayscale;        /* 0 = color, 1 = grayscale,    */
                            /* >1 = FOURCC          */
    struct fb_bitfield red;     /* bitfield in fb mem if true color, */
    struct fb_bitfield green;   /* else only length is significant */
    struct fb_bitfield blue;
    struct fb_bitfield transp;  /* transparency         */  
    __u32 nonstd;           /* != 0 Non standard pixel format */
    __u32 activate;         /* see FB_ACTIVATE_*        */
    __u32 height;           /* height of picture in mm    */
    __u32 width;            /* width of picture in mm     */
    __u32 accel_flags;      /* (OBSOLETE) see fb_info.flags */

    /* Timing: All values in pixclocks, except pixclock (of course) */
    __u32 pixclock;         /* pixel clock in ps (pico seconds) */
    __u32 left_margin;      /* time from sync to picture    */
    __u32 right_margin;     /* time from picture to sync    */
    __u32 upper_margin;     /* time from sync to picture    */
    __u32 lower_margin;
    __u32 hsync_len;        /* length of horizontal sync    */
    __u32 vsync_len;        /* length of vertical sync  */
    __u32 sync;             /* see FB_SYNC_*        */
    __u32 vmode;            /* see FB_VMODE_*       */
    __u32 rotate;           /* angle we rotate counter clockwise */
    __u32 colorspace;       /* colorspace for FOURCC-based modes */
    __u32 reserved[4];      /* Reserved for future compatibility */
};

成员

G0、G1图层，下表中的Gx_min、Gy_min为32；G2、G3、G4图层，下表中的Gx_min、Gy_min为8。Gx_min表示当前图层支持的最小宽度，Gy_min表示当前图层支持的最小高度。