TextureManager Class Reference

Management of OpenGL textures. More...

#include <easy3d/renderer/texture_manager.h>

Static Public Member Functions
static Texture *	request_white ()
	Request a cached 1x1 white texture for inactive surface samplers.
static Texture *	request (const std::string &image_file, Texture::WrapMode wrap=Texture::CLAMP_TO_EDGE, Texture::FilterMode filter=Texture::LINEAR)
	Request a texture from the image file.
static Texture *	request (const std::string &image_file, int num_stripes, Texture::WrapMode wrap=Texture::CLAMP_TO_EDGE, Texture::FilterMode filter=Texture::LINEAR)
	Request a texture for rendering scalar fields from a gradually varying (from left to right) color image given its file name.
static Texture *	request (int num_stripes, int stride, Texture::WrapMode wrap=Texture::CLAMP_TO_EDGE, Texture::FilterMode filter=Texture::LINEAR)
	Request a random color texture for rendering scalar fields. The texture will have a set of uniformly colored vertical stripes.
static void	release (const Texture *texture)
	Release a texture (deallocate its memory).
static void	terminate ()
	Destroy all textures and release their memory.

Detailed Description

Management of OpenGL textures.

A texture can be shared by multiple models, so it is wise to have a single instance of a texture. TextureManager manages the texture creation and memories. It ensures no duplication.

Note

Make sure to call terminate() to destroy existing textures before the OpenGL context is deleted.

Todo:

Allow to change the wrap/filter mode (i.e., multiple textures of different parameters from the same image).

Member Function Documentation

release()

void release ( const Texture *  texture )

static

Release a texture (deallocate its memory).

Parameters

texture

The texture to be released.

request() [1/3]

Texture * request ( const std::string &  image_file, int  num_stripes, Texture::WrapMode  wrap = Texture::CLAMP_TO_EDGE, Texture::FilterMode  filter = Texture::LINEAR  )

static

Request a texture for rendering scalar fields from a gradually varying (from left to right) color image given its file name.

This method allows to sample the original image into a specified number of vertical stripes. The generated texture has a unique identifier in the format: "file_name|num_stripes". If a texture with the same identifier is requested again, no new texture will be generated and the existing one is returned.

Parameters

image_file	The full path to the image file.
num_stripes	The number of stripes. If num_stripes == image_width, no sampling will occur.
wrap	The wrap mode.
filter	The filter mode.

Returns

The texture created from the image.

request() [2/3]

Texture * request ( const std::string &  image_file, Texture::WrapMode  wrap = Texture::CLAMP_TO_EDGE, Texture::FilterMode  filter = Texture::LINEAR  )

static

Request a texture from the image file.

The generated texture has a unique identifier of its full-path file name. If a texture with the same identifier is requested again, no new texture will be generated and the existing texture is returned.

Parameters

image_file	The full path to the image file.
wrap	The wrap mode.
filter	The filter mode.

Returns

The texture created from the image.

Examples

Tutorial_308_TexturedMesh/main.cpp.

request() [3/3]

Texture * request ( int  num_stripes, int  stride, Texture::WrapMode  wrap = Texture::CLAMP_TO_EDGE, Texture::FilterMode  filter = Texture::LINEAR  )

static

Request a random color texture for rendering scalar fields. The texture will have a set of uniformly colored vertical stripes.

It first generates a random-colored image, where each row has "num_colors" color and each color repeat "stride" times. Then, a texture is created from this image data. The generated texture has a unique identifier in the format: "random|num_stripes|stride", where num_stripes and stride are integer numbers. If the requested number of stripes and the stride match a previously generated texture, no new texture will be generated and the existing texture is returned.

Parameters

num_stripes	The number of stripes in the texture.
stride	The width of each vertical strip. So the total width of the texture is: num_stripes * stride.
wrap	The wrap mode.
filter	The filter mode.

Returns

The texture created.

request_white()

Texture * request_white ( )

static

Request a cached 1x1 white texture for inactive surface samplers.

Some drivers validate samplers even when their shader branches are disabled. The texture is released by terminate(), like other cached textures.

Returns

The texture, or nullptr if allocation fails. Requires a current context.

terminate()

void terminate ( )

static

Destroy all textures and release their memory.

Note

This method should be called before the OpenGL context is deleted. It is typically called in the destructor of the viewer.

Examples

Tutorial_203_Viewer_wxWidgets/main.cpp, and Tutorial_204_Viewer_Qt/main.cpp.

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The documentation for this class was generated from the following files:

• easy3d/renderer/texture_manager.h
• easy3d/renderer/texture_manager.cpp