gp_transform.h File Reference

Coordinate transformations for gp_pixmap swap flags. More...

#include <core/gp_common.h>

Go to the source code of this file.

Macros
#define	GP_TRANSFORM_X(pixmap, x)
	Flips x coordinate within pixmap according to the x_swap flag.
#define	GP_TRANSFORM_Y(pixmap, y)
	Flips y coordinate within pixmap according to the y_swap flag.
#define	GP_TRANSFORM_SWAP(pixmap, x, y)
	Swaps coordinates within pixmap according to the axes_swap flag.
#define	GP_TRANSFORM_POINT(pixmap, x, y)
	Does the complete coordinate transformation accordingly to transformation flags.
#define	GP_TRANSFORM_RECT(pixmap, x, y, w, h)
	Transforms a rectangle accordingly to the transformation flags.
#define	GP_RETRANSFORM_POINT(pixmap, x, y)
	An inverse transformation to GP_TRANSFORM_POINT().

Detailed Description

Coordinate transformations for gp_pixmap swap flags.

These transformations are applied before a complex shapes are rendered into a gp_pixmap, e.g. each polygon coordinate is transformed before the polygon rendering algorithm starts.

Definition in file gp_transform.h.

Macro Definition Documentation

GP_RETRANSFORM_POINT

#define GP_RETRANSFORM_POINT	(		pixmap,
			x,
			y
	)

Value:

        do { \
        GP_TRANSFORM_X(pixmap, x);              \
        GP_TRANSFORM_Y(pixmap, y);              \
        GP_TRANSFORM_SWAP(pixmap, x, y);        \
} while (0)

An inverse transformation to GP_TRANSFORM_POINT().

Used to translate mouse pointer coordinates to coordinates on pixmap.

Attention

Modifies the x and y variables passed as argument.

Parameters

pixmap	A pixmap.
x	An x coordinate that may be transformed.
y	An y coordinate that may be transformed.

Definition at line 129 of file gp_transform.h.

GP_TRANSFORM_POINT

#define GP_TRANSFORM_POINT	(		pixmap,
			x,
			y
	)

Value:

        do { \
        GP_TRANSFORM_SWAP(pixmap, x, y);      \
        GP_TRANSFORM_X(pixmap, x);            \
        GP_TRANSFORM_Y(pixmap, y);            \
} while (0)

Does the complete coordinate transformation accordingly to transformation flags.

Uses the gp_pixmap::axes_swap, gp_pixmap::x_swap and gp_pixmap::y_swap flags to transform the coordinates.

Attention

Modifies the x and y variables passed as argument.

Parameters

pixmap	A pixmap.
x	An x coordinate that may be transformed.
y	An y coordinate that may be transformed.

Definition at line 78 of file gp_transform.h.

GP_TRANSFORM_RECT

#define GP_TRANSFORM_RECT	(		pixmap,
			x,
			y,
			w,
			h
	)

Value:

        do { \
        GP_TRANSFORM_SWAP(pixmap, x, y);           \
        GP_TRANSFORM_SWAP(pixmap, w, h);           \
                                                   \
        if ((pixmap)->x_swap)                      \
                x = (pixmap)->w - x - w;           \
                                                   \
        if ((pixmap)->y_swap)                      \
                y = (pixmap)->h - y - h;           \
} while (0)

Transforms a rectangle accordingly to the transformation flags.

Attention

Modifies the x, y, w, and h variables passed as argument.

Parameters

pixmap	A pixmap.
x	A left x coordinate of a rectangle.
y	A top y coordinate of a rectangle.
w	A rectangle width.
h	A rectangle height.

Definition at line 95 of file gp_transform.h.

GP_TRANSFORM_SWAP

#define GP_TRANSFORM_SWAP	(		pixmap,
			x,
			y
	)

Value:

        do { \
        if ((pixmap)->axes_swap)             \
                GP_SWAP(x, y);               \
} while (0)

Swaps coordinates within pixmap according to the axes_swap flag.

Attention

Modifies the x and y variables passed as argument.

Parameters

pixmap	A pixmap.
x	An x coordinate that may be swapped with y coordinate.
y	An y coordinate that may be swapped with x coordinate.

Definition at line 60 of file gp_transform.h.

GP_TRANSFORM_X

#define GP_TRANSFORM_X	(		pixmap,
			x
	)

Value:

        do {   \
        if ((pixmap)->x_swap)            \
                x = (pixmap)->w - x - 1; \
} while (0)

Flips x coordinate within pixmap according to the x_swap flag.

Attention

Modifies the y variable passed as argument.

Parameters

pixmap	A pixmap.
x	An x coordinate that may be flipped.

Definition at line 33 of file gp_transform.h.

GP_TRANSFORM_Y

#define GP_TRANSFORM_Y	(		pixmap,
			y
	)

Value:

        do {   \
        if ((pixmap)->y_swap)            \
                y = (pixmap)->h - y - 1; \
} while (0)

Flips y coordinate within pixmap according to the y_swap flag.

Attention

Modifies the y variable passed as argument.

Parameters

pixmap	A pixmap.
y	An y coordinate that may be flipped.

Definition at line 46 of file gp_transform.h.