预定义常量

下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。

GD_VERSION (string)

PHP 编译所依据的 GD 版本。

GD_MAJOR_VERSION (int)

PHP 编译所依据的 GD 大版本。

GD_MINOR_VERSION (int)

PHP 编译所依据的 GD 小版本。

GD_RELEASE_VERSION (int)

PHP 编译所依据的 GD 发布版本。

GD_EXTRA_VERSION (string)

PHP 编译所依据的 GD 扩展版本（beta/rc..）。

GD_BUNDLED (int)

当使用绑定版本的 GD 时，此值为 1，反之为 0。

IMG_AVIF (int)

Used as a return value by imagetypes()

（自 PHP 8.1.0 起可用）

IMG_BMP (int)

Used as a return value by imagetypes()

IMG_GIF (int)

Used as a return value by imagetypes()

IMG_JPG (int)

Used as a return value by imagetypes()

IMG_JPEG (int)

Used as a return value by imagetypes()

注意:
本常量值同 IMG_JPG

IMG_PNG (int)

Used as a return value by imagetypes()

IMG_TGA (int)

Used as a return value by imagetypes()

（自 PHP 7.4.0 起可用）

IMG_WBMP (int)

Used as a return value by imagetypes()

IMG_XPM (int)

Used as a return value by imagetypes()

IMG_WEBP (int)

Used as a return value by imagetypes()

（自 PHP 7.0.10 起可用）

IMG_WEBP_LOSSLESS (int)

（自 PHP 8.1.0 起可用）

IMG_COLOR_TILED (int)

Special color option which can be used instead of a color allocated with imagecolorallocate() or imagecolorallocatealpha().

IMG_COLOR_STYLED (int)

Special color option which can be used instead of a color allocated with imagecolorallocate() or imagecolorallocatealpha().

IMG_COLOR_BRUSHED (int)

Special color option which can be used instead of a color allocated with imagecolorallocate() or imagecolorallocatealpha().

IMG_COLOR_STYLEDBRUSHED (int)

Special color option which can be used instead of a color allocated with imagecolorallocate() or imagecolorallocatealpha().

IMG_COLOR_TRANSPARENT (int)

Special color option which can be used instead of a color allocated with imagecolorallocate() or imagecolorallocatealpha().

IMG_AFFINE_TRANSLATE (int)

An affine transformation type constant used by the imageaffinematrixget() function.

IMG_AFFINE_SCALE (int)

An affine transformation type constant used by the imageaffinematrixget() function.

IMG_AFFINE_ROTATE (int)

An affine transformation type constant used by the imageaffinematrixget() function.

IMG_AFFINE_SHEAR_HORIZONTAL (int)

An affine transformation type constant used by the imageaffinematrixget() function.

IMG_AFFINE_SHEAR_VERTICAL (int)

An affine transformation type constant used by the imageaffinematrixget() function.

IMG_ARC_ROUNDED (int)

A style constant used by the imagefilledarc() function.

注意:
此常量值同 IMG_ARC_PIE

IMG_ARC_PIE (int)

A style constant used by the imagefilledarc() function.

IMG_ARC_CHORD (int)

A style constant used by the imagefilledarc() function.

IMG_ARC_NOFILL (int)

A style constant used by the imagefilledarc() function.

IMG_ARC_EDGED (int)

A style constant used by the imagefilledarc() function.

IMG_GD2_RAW (int)

A type constant used by the imagegd2() function.

IMG_GD2_COMPRESSED (int)

A type constant used by the imagegd2() function.

IMG_EFFECT_REPLACE (int)

Alpha blending effect used by the imagelayereffect() function.

IMG_EFFECT_ALPHABLEND (int)

Alpha blending effect used by the imagelayereffect() function.

IMG_EFFECT_NORMAL (int)

Alpha blending effect used by the imagelayereffect() function.

IMG_EFFECT_OVERLAY (int)

Alpha blending effect used by the imagelayereffect() function.

IMG_EFFECT_MULTIPLY (int)

Alpha blending effect used by the imagelayereffect() function.

IMG_FILTER_NEGATE (int)