Author: eilemann@gmail.com
State: Implemented in 0.4.
Overview
This features adds support for resizing windows without changing the aspect ratio of the OpenGL rendering in order to avoid the distortion of the model. Upon the size change of the associated channel, the horizontal or vertical field of view (FOV) of the wall or projection description is updated so that rendering is not 'stretched'.
Implementation
Modify the wall's width or height or the projection's horizontal or vertical field of view upon a channel pixel viewport size change. Upon Compound::setChannel, the compound subscribes to the channel viewport change notification. Add PixelViewportListener 'interface' and channel PVPListener add/remove/notify API. Refactor the existing window/channel size notifications to use new listener API.
Retain the initial pvp in the compound upon the first channel pvp notification. Upon subsequent pvp notifications, compute the relative change to the initial value and adapt wall or projection accordingly. Applying the change using the original wall or projection is necessary to eliminate the accumulation of rounding errors if incremental updates would be used.
API
class PixelViewportListener
{
virtual void notifyPVPChanged( const eq::PixelViewport& pvp ) {}
}
class Compound : public PixelViewportListener
{ ... }
File Format
- HORIZONTAL: The horizontal FOV or wall width is changed to maintain the initial aspect ratio. The vertical field of view or wall height is unchanged. The rendered content appears resized.
- VERTICAL: Like HORIZONTAL, but the vertical FOV or wall height is changed
- BOTH: Both the vertical and horizontal FOV are changed, so that the model rendering remains the same size, centered in the middle of the channel.
global
{
EQ_COMPOUND_IATTR_UPDATE_FOV HORIZONTAL [ON] | VERTICAL | BOTH | OFF
}
compound
{
attributes
{
update_FOV HORIZONTAL [ON] | VERTICAL | BOTH | OFF
}
}
Restrictions
The BOTH strategy will be implemented later.
Open Issues
None
