A Cinder block for using Nvidia Path extensions
This block will only work on Nvidia Cards with a driver that has the Path SDK extensions. Visual studio 2012 project files are included. Should work on Linux as well. The Nvidia Path Rendering SDK uses a stencil and cover approach where the driver initially rasterizes paths to the stencil buffer and then covers the path's area with simple geometry which gives it shading capabilities. See https://developer.nvidia.com/nv-path-rendering for more info on the Nvidia Path Rendering SDK. For some text functionality you will need a copy of the freetype dll in your system path. I have included a .dll in the source.
#Notes for building samples
A copy of AppImplMswRendererGl.cpp is included in the source files to allow overriding the precompiled Cinder application code that disables the stencil buffer. A copy of an updated Glee.h and Glee.c is included in the source which has the ability to load the nvidia path extensions. You must replace your copy of glee.h and glee.c with these files and then rebuild your cinder libraries. The include and library paths are referenced via the environment variable CINDER_DIR. Either remove the references to CINDER_DIR in the project settings or add an environment variable pointing to your Cinder root dir.
#Features:
- Resolution independent path drawing
- Text Field Kerning
- Stroked text
- Truetype and OpenType system font path loading and metrics parsing using freetype2 implementation
- Blazing fast gpu stencil buffer drawing method
- Instanced drawing of glyphs so each font glyph is loaded only once to the gpu and then instanced for every textbox using that font (regardless of point size)
- Very lightweight library (no source or include files, everything is in the nvidia driver)
- Underline decoration
- Typographically accurate bounds and positioning
- First class support in the OpenGL pipeline: can be transformed in 3D with OpenGL matrix transforms, can be properly depth tested with 3D geometry, can be textured with a fragment shader, can take advantage of the driver’s stochastic multi-sampling anti-aliasing functionality
#ToDo:
- generic path drawing functions
- example showing 3D transformation support
- example showing shader support
- svg loading and rendering
- svg gradient shader implementation
- example showing svg path instancing
- dynamic svg driven text paths
- dash decoration on paths
- font independent stroking (different stroking for multiple text fields using the same font)
#Issues:
- Requires newer version of GLEE than Cinder’s default to load extensions
- Requires stencil buffer which is disabled by default in Cinder
- No vertex shader support. can get a 2d mapping for texturing but cannot query 3d position in shader so no fancy shadowing text
- Requires Nvidia card. probably doesn’t work on Mac
- Hacky emScale to point conversion
- Dependency on Nvidia driver code
Example image:
Cinder TextBox column on left. Cinder-NVP textbox column on right.
Stress Test Example Video: https://vimeo.com/103757940