Sampler#

class Sampler#

Returned by Context.sampler()

A Sampler Object is an OpenGL Object that stores the sampling parameters for a Texture access inside of a shader.

When a sampler object is bound to a texture image unit, the internal sampling parameters for a texture bound to the same image unit are all ignored. Instead, the sampling parameters are taken from this sampler object.

Unlike textures, a samplers state can also be changed freely be at any time without the sampler object being bound/in use.

Samplers are bound to a texture unit and not a texture itself. Be careful with leaving samplers bound to texture units as it can cause texture incompleteness issues (the texture bind is ignored).

Sampler bindings do clear automatically between every frame so a texture unit need at least one bind/use per frame.

Methods#

Sampler.use(location: int = 0) → None:#

Bind the sampler to a texture unit.

Parameters:: location (int) – The texture unit

Sampler.clear(location: int = 0) → None:#

Clear the sampler binding on a texture unit.

Parameters:: location (int) – The texture unit

Sampler.assign(index: int) → tuple#

Helper method for assigning samplers to scopes.

Example:

s1 = ctx.sampler(...)
s2 = ctx.sampler(...)
ctx.scope(samplers=(s1.assign(0), s1.assign(1)), ...)mpler

Sampler.release()#

Attributes#

Sampler.texture: Texture#: The texture object to sample.

Sampler.repeat_x: bool#

The x repeat flag for the sampler (Default True).

Example:

# Enable texture repeat (GL_REPEAT)
sampler.repeat_x = True

# Disable texture repeat (GL_CLAMP_TO_EDGE)
sampler.repeat_x = False

Sampler.repeat_y: bool#

The y repeat flag for the sampler (Default True).

Example:

# Enable texture repeat (GL_REPEAT)
sampler.repeat_y = True

# Disable texture repeat (GL_CLAMP_TO_EDGE)
sampler.repeat_y = False

Sampler.repeat_z: bool#

The z repeat flag for the sampler (Default True).

Example:

# Enable texture repeat (GL_REPEAT)
sampler.repeat_z = True

# Disable texture repeat (GL_CLAMP_TO_EDGE)
sampler.repeat_z = False

Sampler.filter: tuple#

The minification and magnification filter for the sampler.

(Default (moderngl.LINEAR. moderngl.LINEAR))

Example:

sampler.filter == (moderngl.NEAREST, moderngl.NEAREST)
sampler.filter == (moderngl.LINEAR_MIPMAP_LINEAR, moderngl.LINEAR)
sampler.filter == (moderngl.NEAREST_MIPMAP_LINEAR, moderngl.NEAREST)
sampler.filter == (moderngl.LINEAR_MIPMAP_NEAREST, moderngl.NEAREST)

Sampler.compare_func: tuple#

The compare function for a depth textures (Default '?').

By default samplers don’t have depth comparison mode enabled. This means that depth texture values can be read as a sampler2D using texture() in a GLSL shader by default.

When setting this property to a valid compare mode, GL_TEXTURE_COMPARE_MODE is set to GL_COMPARE_REF_TO_TEXTURE so that texture lookup functions in GLSL will return a depth comparison result instead of the actual depth value.

Accepted compare functions:

.compare_func = ''    # Disale depth comparison completely
sampler.compare_func = '<='  # GL_LEQUAL
sampler.compare_func = '<'   # GL_LESS
sampler.compare_func = '>='  # GL_GEQUAL
sampler.compare_func = '>'   # GL_GREATER
sampler.compare_func = '=='  # GL_EQUAL
sampler.compare_func = '!='  # GL_NOTEQUAL
sampler.compare_func = '0'   # GL_NEVER
sampler.compare_func = '1'   # GL_ALWAYS

Sampler.anisotropy: float#

Number of samples for anisotropic filtering (Default 1.0).

The value will be clamped in range 1.0 and ctx.max_anisotropy.

Any value greater than 1.0 counts as a use of anisotropic filtering:

# Disable anisotropic filtering
sampler.anisotropy = 1.0

# Enable anisotropic filtering suggesting 16 samples as a maximum
sampler.anisotropy = 16.0

Sampler.border_color: tuple#

The (r, g, b, a) color for the texture border (Default (0.0, 0.0, 0.0, 0.0)).

When setting this value the repeat_ values are overridden setting the texture wrap to return the border color when outside [0, 1] range.

Example:

# Red border color
sampler.border_color = (1.0, 0.0, 0.0, 0.0)

Sampler.min_lod: float#

Minimum level-of-detail parameter (Default -1000.0).

This floating-point value limits the selection of highest resolution mipmap (lowest mipmap level)

Sampler.max_lod: float#

Minimum level-of-detail parameter (Default 1000.0).

This floating-point value limits the selection of the lowest resolution mipmap (highest mipmap level)

Sampler.ctx: Context#: The context this object belongs to

Sampler.glo: int#: The internal OpenGL object. This values is provided for interoperability and debug purposes only.

Sampler.extra: Any#: User defined data.