nv_path_rendering
TRANSCRIPT
An Introduction toNV_path_rendering
Mark J. KilgardNVIDIA Corporation
June 8, 2011
Purpose of this Presentation
Overview of GPU-accelerated path renderingUsing “stencil, then cover”
Explain and demonstrate the NV_path_rendering APIAimed primarily at programmers
Introduce you to the content of NVIDIA’s NVpr SDK
What is path rendering?A rendering approach
Resolution-independent two-dimensional graphicsOcclusion & transparency depend on rendering order
So called “Painter’s Algorithm”Basic primitive is a path to be filled or stroked
Path is a sequence of path commandsCommands are
– moveto, lineto, curveto, arcto, closepath, etc.
StandardsContent: PostScript, PDF, TrueType fonts, Flash, Scalable Vector Graphics (SVG), HTML5 Canvas, Silverlight, Office drawingsAPIs: Apple Quartz 2D, KhronosOpenVG, Microsoft Direct2D, Cairo, Skia, Qt::QPainter, Anti-grain Graphics,
Path Filling vs. Stroking
just filling just stroking
filling + stroke =intended content
Handling Common Path RenderingFunctionality: Filtering
GPUs are highly efficient at image filtering
Fast texture mappingMipmappingAnisotropic filteringWrap modes
CPUs aren't really
� GPU
� Qt
� Cairo
Moiréartifacts
Projective Path Rendering SupportCompared
� GPUflawless
� Skiayes, but bugs
� Cairounsupported
� Qtunsupported
correct
wrong
correct
correct
unsupported
unsupported
unsupported
unsupported
Rendering Paths Clipped toSome Other Arbitrary Path
Example clipping the PostScript tiger to a heart constructed from two cubic Bezier curves
unclipped tiger tiger with pink background clipped to heart
Benchmark Scenes
Tiger Dragon Round Dogs Butterfly Spikes
Coat of Arms Cowboy Buonaparte Embrace Japanese Strokes
Learning NV_path_rendering
White paper + source code available“Getting Started with NV_path_rendering”
ExplainsPath specification“Stencil, then Cover” API usageInstanced rendering for text and glyphs
