Macros

Macros — Macros

Synopsis




#define     oil_min                         (x,y)
#define     oil_max                         (x,y)
#define     oil_divide_255                  (x)
#define     oil_argb                        (a,r,g,b)
#define     oil_argb_noclamp                (a,r,g,b)
#define     oil_argb_A                      (color)
#define     oil_argb_G                      (color)
#define     oil_argb_B                      (color)
#define     oil_argb_R                      (color)
#define     oil_muldiv_255                  (a,b)
#define     oil_clamp_255                   (x)
#define     OIL_GET                         (ptr, offset, type)
#define     OIL_OFFSET                      (ptr, offset)
#define     OIL_INCREMENT                   (ptr, offset)

Description

Details

oil_min()

#define oil_min(x,y) ((x)<(y)?(x):(y))

Evaluates to the minimum of x and y.

`x` :	a value
`y` :	a value

oil_max()

#define oil_max(x,y) ((x)>(y)?(x):(y))

Evaluates to the maximum of x and y.

`x` :	a value
`y` :	a value

oil_divide_255()

#define oil_divide_255(x) ((((x)+128) + (((x)+128)>>8))>>8)

Divides x by 255 in a way that is compatible with the pixel operations in Liboil.

Evaluates to x divided by 255.

x : a value in the range [0,255]

oil_argb()

#define     oil_argb(a,r,g,b)

Creates a Liboil ARGB value from individual components. Clamps each component to [0,255].

Evaluates to the ARGB value

`a` :	alpha component
`r` :	red component
`g` :	green component
`b` :	blue component

oil_argb_noclamp()

#define     oil_argb_noclamp(a,r,g,b)

Creates a Liboil ARGB value from individual components. Does not clamp components.

Evaluates to the ARGB value

`a` :	alpha component
`r` :	red component
`g` :	green component
`b` :	blue component

oil_argb_A()

#define oil_argb_A(color) (((color)>>24)&0xff)

Extracts the alpha component from color.

Evaluates to the alpha component

color : an ARGB value

oil_argb_G()

#define oil_argb_G(color) (((color)>>8)&0xff)

Extracts the green component from color.

Evaluates to the green component

color : an ARGB value

oil_argb_B()

#define oil_argb_B(color) (((color)>>0)&0xff)

Extracts the blue component from color.

Evaluates to the blue component

color : an ARGB value

oil_argb_R()

#define oil_argb_R(color) (((color)>>16)&0xff)

Extracts the red component from color.

Evaluates to the red component

color : an ARGB value

oil_muldiv_255()

#define oil_muldiv_255(a,b) oil_divide_255((a)*(b))

Multiplies a and b and divides the result by 255 in a way that is compatible with the pixel operations in Liboil.

Evaluates to the result.

`a` :	a value in the range [0,255]
`b` :	a value in the range [0,255]

oil_clamp_255()

#define oil_clamp_255(x) oil_max(0,oil_min((x),255))

Clamps x to the range [0,255].

Evaluates to the clamped value.

x : a value

OIL_GET()

#define OIL_GET(ptr, offset, type) (*(type *)((uint8_t *)ptr + (offset)) )

Offsets ptr by offset number of bytes, and dereferences it as type type. Note that the offset is in bytes, and not in the size of the pointer type.

`ptr` :
`offset` :
`type` :

OIL_OFFSET()

#define OIL_OFFSET(ptr, offset) ((void *)((uint8_t *)ptr + (offset)) )

Add offset bytes to the pointer ptr.

`ptr` :
`offset` :

OIL_INCREMENT()

#define OIL_INCREMENT(ptr, offset) (ptr = (void *)((uint8_t *)ptr + (offset)) )

Increments the pointer ptr by offset number of bytes.

`ptr` :
`offset` :