Dali: FloatImage -- C API

Header Files


#include <dvmbasic.h>

Type Definitions

FloatImage

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


    typedef struct FloatImage {

        int width;

        int height;

        int x;

        int y;

        int parentWidth;

        unsigned char isVirtual;

        float *firstByte;

    } FloatImage;

width

the width of the FloatImage

height

the height of the FloatImage

x

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

y

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

parentWidth

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

virtual

1 iff the FloatImage is virtual. 0 otherwise.

firstByte

pointer to the first short in this FloatImage.

Constants

Return Codes

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


    #define DVM_FLOAT_OK 0

    #define DVM_FLOAT_ERROR 1

Operators

Allocation

FloatImage *FloatNew (int w, int h)

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

void FloatFree (FloatImage *image)

Deallocate image.

FloatImage *FloatClip (FloatImage *image, int x, int y, int w, int h)

Create a virtual FloatImage 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 FloatImage is returned.

void FloatReclip (FloatImage *image, int x, int y, int w, int h, FloatImage *clipped)

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

Initialization

void FloatCopy (FloatImage *src, FloatImage *dest)

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

Queries

int FloatGetX(FloatImage *image) int FloatGetY(FloatImage *image) int FloatGetWidth(FloatImage *image) int FloatGetHeight(FloatImage *image) int FloatGetVirtual(FloatImage *image)

These functions (macros in the C version) access various fields in the FloatImage 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.