Painter Backend

If one is making a painter backend, then this group provides the information, see particularly the enumerations in fastuidraw::PainterHeader, fastuidraw::PainterItemMatrix, fastuidraw::PainterClipEquations for how data is packed by fastuidraw::Painter. Part of the main library libFastUIDraw. More...

Classes
class	fastuidraw::AtlasColorBackingStoreBase
	Represents the interface for a backing store for color data of images. More...
class	fastuidraw::AtlasIndexBackingStoreBase
	Represents the interface for the backing store for index data of images. More...
class	fastuidraw::ColorStopAtlas
	A ColorStopAtlas is a common location to all color stop data of an application. Ideally, all color stop sequences are placed into a single ColorStopAtlas (changes of ColorStopAtlas force draw-call breaks). More...
class	fastuidraw::ColorStopBackingStore
	Represents the interface for the backing store for the texels of a sequence of color stops. The expectation is that linear filtering acting on the underlying backing store is all that is needed for correct color interpolation from a gradient interpolate. For example in GL, this can be GL_TEXTURE_1D_ARRAY with both minification and magnification filters set as GL_LINEAR. An implementation of the class does NOT need to be thread safe because the user of the backing store (ColorStopAtlas) performs calls to the backing store behind its own mutex. More...
class	fastuidraw::GlyphAtlas
	A GlyphAtlas is a common location to place glyph data of an application. Ideally, all glyph data is placed into a single GlyphAtlas. Methods of GlyphAtlas are thread safe, protected behind atomics and a mutex within the GlyphAtlas. More...
class	fastuidraw::GlyphAtlasBackingStoreBase
	GlyphAtlasStoreBase represents an interface to an aray of uint32_t values. More...
class	fastuidraw::PainterBackend
	A PainterBackend is an interface that defines the API-specific elements to implement Painter. A fixed PainterBackend will only be used by a single Painter. More...
class	fastuidraw::PainterBrushAdjust
	A PainterBrushAdjust holds the value for applying a tranformation to the brush position before it is handed off to brush shading. The transformation is shearing composited with a translation, i.e. the transformation is given by. More...
class	fastuidraw::PainterClipEquations
	A PainterClipEquations stores the clip equation for Painter. More...
class	fastuidraw::PainterDraw
	Store for attributes, indices of items and shared data of items for items to draw. Indices (stored in m_indices) are -ALWAYS- in groups of three where each group is a single triangle and each index is an index into m_attributes. The PainterDraw object is NOT thread safe, neither is its reference count. A PainterDraw object is used Painter to send attributer and index data to a Painter Backend. More...
class	fastuidraw::PainterDrawBreakAction
	A PainterDrawBreakAction represents an action on the 3D API between two indices to be fed the the GPU; a PainterDrawBreakAction will imply an draw break in the underlying 3D API. Typical example of such an action would be to bind a texture. More...
class	fastuidraw::PainterEngine
	A PainterEngine provides an interface to create Painter Backend derived objects. More...
class	fastuidraw::PainterHeader
	A PainterHeader represents the values of the header for the shaders to read to draw data. The header holds data that is common for all vertices and fragments for an item to draw, including with what shader and the data for the shader. More...
class	fastuidraw::PainterItemMatrix
	A PainterItemMatrix holds the value for the transformation from item coordinates to the coordinates in which the clipping rectangle applies. More...
class	fastuidraw::PainterShaderGroup
	A PainterShaderGroup gives to what groups the active shaders of a Painter belong. More...
class	fastuidraw::PainterShaderRegistrar
	A PainterShaderRegistrar is an interface that defines the assigning of PainterShader::ID() to a PainterShader. PainterShader objects are registered to a unique PainterShaderRegistrar for their lifetime. More...
class	fastuidraw::PainterSurface
	PainterSurface represents an interface to specify a buffer to which a PainterBackend renders content. More...

Detailed Description

If one is making a painter backend, then this group provides the information, see particularly the enumerations in fastuidraw::PainterHeader, fastuidraw::PainterItemMatrix, fastuidraw::PainterClipEquations for how data is packed by fastuidraw::Painter. Part of the main library libFastUIDraw.

Overview

The class fastuidraw::Painter implements canvas rendering using an implementation of the backend interface fastuidraw::PainterBackend to send data to a 3D API. The class fastuidraw::Painter packs data that is used by multiple triangles into fastuidraw::PainterDrawCommand::m_store (for example the current transformation). In implementing a backend, the shader fed to the GPU needs to correctly unpack this data. The location of the header of the data is stored in the attribute from the value fastuidraw::PainterDrawCommand::m_header_attributes. The header consists of fastuidraw::PainterHeader::header_size uint32_t values whose location relative to the start of the header and meaning are enumerated by fastuidraw::PainterHeader::offset_t. The header contains shader ID's and additional offsets to more data packed for a shader to unpack.