gf_layer_set_blending()

Set layer blending

Synopsis:

#include <gf/gf.h>

void gf_layer_set_blending( gf_layer_t layer,
                            const gf_alpha_t * alpha );

Arguments:

layer
A pointer to a gf_layer_t handle of the layer you want to set alpha blending for.
alpha
A gf_alpha_t structure describing the new blending.

Library:

gf

Description:

This function gives you control over layer blending (that is, opacity), allowing you to make a layer fully opaque, transparent, or semitransparent.


Note: Changes to the layer's parameters are enqueued. You need to call gf_layer_update() to make them take effect.

The blending parameters normally control how the contents of the layer are blended with intersecting layers that are behind the specified layer.


Note:
  • For the blending operation, the attached layer can be thought of as the “source” while the layer(s) behind can be thought of as the “destination.”
  • There are hardware limitations to alpha blending operations. Please see the “Hardware Capabilities” Appendix for more details.

Classification:

QNX Graphics Framework

Safety:
Interrupt handler No
Signal handler No
Thread Yes

See also:

gf_alpha_t, gf_layer_query(), gf_layer_update()