Dali: Byte32Image -- C API

Header Files

#include <dvmbasic.h>

Type Definitions

Byte32Image

A Byte32Image is a buffer storing 2D array of int. Just like a ByteImage, a Byte32Image can be either physical or virtual.

    typedef struct Byte32Image {
        int width;
        int height;
        int x;
        int y;
        int parentWidth;
        unsigned char isVirtual;
        int *firstByte;
    } Byte32Image;

width

the width of the Byte32Image

height

the height of the Byte32Image

x

the x-offset of the top-left corner of the Byte32Image from it's parent.

y

the y-offset of the top-left corner of the Byte32Image from it's parent.

parentWidth

the width of the physical parent of this Byte32Image. (should be called rootWidth since the parent might not be physical)

virtual

1 iff the Byte32Image is virtual. 0 otherwise.

firstByte

pointer to the first short in this Byte32Image.

Constants

Return Codes

Return codes from various byte32 primitives. DVM_BYTE32_OK indicates the primitives executed successfully. DVM_BYTE32_ERROR indicates some error has occurs. We may defined more error codes to indicates different type of errors.

    #define DVM_BYTE32_OK 0
    #define DVM_BYTE32_ERROR 1

Operators

Allocation

Byte32Image *Byte32New (int w, int h)

Create a new physical Byte32Image with w x h shorts and return a pointer to that Byte32Image.

void Byte32Free (Byte32Image *image)

Deallocate image.

Byte32Image *Byte32Clip (Byte32Image *image, int x, int y, int w, int h)

Create a virtual Byte32Image of size w by h, with image as the parent, and offset (x, y) from the upper-left corner of image. A pointer to the new Byte32Image is returned.

void Byte32Reclip (Byte32Image *image, int x, int y, int w, int h, Byte32Image *clipped)

This function is identical to Byte32Clip, except that it destructively modifies the virtual Byte32Image clipped (instead of creating a new virtual Byte32Image). Warning : memory leaks will occurs if clipped is a physical Byte32Image.

Initialization

void Byte32Copy (Byte32Image *src, Byte32Image *dest)

Copy the top-left w x h area of Byte32Image src into Byte32Image dest, where w and h are minimum width and height of src and dest.

Queries

int Byte32GetX(Byte32Image *image) int Byte32GetY(Byte32Image *image) int Byte32GetWidth(Byte32Image *image) int Byte32GetHeight(Byte32Image *image) int Byte32GetVirtual(Byte32Image *image)

These functions (macros in the C version) access various fields in the Byte32Image data structure. The first two function return the x or y offset of image within its parent, the next two return the width or height of image, and the last function returns 1 if image is virtual, 0 otherwise.