NVPR Cursive Text Sample


Category:  Visuals
Min PC GPU: Fermi-based (GTX 4xx)
Min Tegra Device: Tegra K1

Description

This sample demonstrates how to use NV_path_rendering to animate the dash pattern of a stroked path, as a way to simulate live cursive writing.

APIs Used

Shared User Interface

The OpenGL samples all share a common app framework and certain user interface elements, centered around the "Tweakbar" panel on the left side of the screen, which lets you interactively control certain variables in each sample.

To show and hide the Tweakbar, simply click or touch the triangular button positioned in the top-left of the view.

Other controls are listed below.

Device Input Result
touch 2-Finger Drag Translate the view
2-Finger Pinch Scale the view
mouse Left-Click Drag Translate the view
Right-Click Drag Scale the view (up:out, down:in)
keyboard Escape Quit the application
  Tab Toggle Tweakbar visibility
gamepad Start Toggle Tweakbar visibility

App-Specific Controls

This sample has the following app-specific controls:

Device Input Result
keyboard space Toggle Animation
R Reset Scene
, / . Decrease/Increase Animation State
gamepad Y Toggle Animation
X Reset Scene
DPAD Left/Right Decrease/Increase Animation State

Technical Details

An outline for the text "This is crazy" is drawn incrementally by computing the total arc length of the path using glGetPathLengthNVand then setting the dash pattern with glPathDashArrayNVto be some percentage of that total path length. By animating the dash pattern in this way, the stroking of the path appears to animate in way to trace out the path's outline.

See Also

 

 


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