Magnum::Text::GlyphCacheArrayGL class new in Git master
#include <Magnum/Text/GlyphCacheGL.h>

OpenGL array glyph cache.

Implementation of an AbstractGlyphCache backed by a GL::Texture2DArray, other than that equivalent to GlyphCacheGL. See the AbstractGlyphCache class documentation for information about setting up a glyph cache instance and filling it with glyphs, and GlyphCacheGL for details on how the internal texture format is picked. The setup differs from GlyphCacheGL only in specifying one extra dimension for size:

Containers::Pointer<Text::AbstractFont> font = …;

Text::GlyphCacheArrayGL cache{PixelFormat::R8Unorm, {256, 256, 8}};
if(!font->fillGlyphCache(cache, "abcdefghijklmnopqrstuvwxyz"
                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                                "0123456789?!:;,. "))
    Fatal{} << "Glyph cache too small to fit all characters";

Assuming a RendererGL is used with this cache for rendering the text, its mesh() can be then drawn using Shaders::VectorGL that has Shaders::VectorGL::Flag::TextureArrays enabled, together with binding texture() for drawing:

Text::RendererGL renderer{cache};
…

Shaders::VectorGL2D shader{Shaders::VectorGL2D::Configuration{}
    .setFlags(Shaders::VectorGL2D::Flag::TextureArrays)
};
shader
    …
    .bindVectorTexture(cache.texture())
    .draw(renderer.mesh());

Base classes

class AbstractGlyphCache new in 2019.10
Base for glyph caches.

Constructors, destructors, conversion operators

GlyphCacheArrayGL(PixelFormat format, const Vector3i& size, const Vector2i& padding = Vector2i{1}) explicit new in Git master
Constructor.
GlyphCacheArrayGL(PixelFormat format, const Vector3i& size, PixelFormat processedFormat, const Vector2i& processedSize, const Vector2i& padding = Vector2i{1}) explicit new in Git master
Construct with a specific processed format and size.
GlyphCacheArrayGL(NoCreateT) explicit noexcept new in Git master
Construct without creating the internal state and the OpenGL texture object.

Public functions

auto texture() -> GL::Texture2DArray&
Cache texture.

Function documentation

Magnum::Text::GlyphCacheArrayGL::GlyphCacheArrayGL(PixelFormat format, const Vector3i& size, const Vector2i& padding = Vector2i{1}) explicit new in Git master

Constructor.

Parameters
format Source image format
size Source image size size in pixels
padding Padding around every glyph in pixels

The size is expected to be non-zero. If the implementation advertises GlyphCacheFeature::ImageProcessing, the processedFormat() and processedSize() is the same as format and size, use AbstractGlyphCache(PixelFormat, const Vector3i&, PixelFormat, const Vector2i&, const Vector2i&) to specify different values.

Magnum::Text::GlyphCacheArrayGL::GlyphCacheArrayGL(PixelFormat format, const Vector3i& size, PixelFormat processedFormat, const Vector2i& processedSize, const Vector2i& padding = Vector2i{1}) explicit new in Git master

Construct with a specific processed format and size.

Parameters
format Source image format
size Source image size size in pixels
processedFormat Processed image format
processedSize Processed glyph cache texture size in pixels
padding Padding around every glyph in pixels. See Glyph padding for more information about the default.

The size and processedSize is expected to be non-zero, depth of processed size is implicitly the same as in size. All glyphs are saved in format relative to size and with padding, although the actual glyph cache texture is in processedFormat and has processedSize.

Magnum::Text::GlyphCacheArrayGL::GlyphCacheArrayGL(NoCreateT) explicit noexcept new in Git master

Construct without creating the internal state and the OpenGL texture object.

The constructed instance is equivalent to moved-from state, i.e. no APIs can be safely called on the object. Useful in cases where you will overwrite the instance later anyway. Move another object over it to make it useful.

This function can be safely used for constructing (and later destructing) objects even without any OpenGL context being active. However note that this is a low-level and a potentially dangerous API, see the documentation of NoCreate for alternatives.