CC3Fog controls fog in the 3D world. More...
#import <CC3Fog.h>
Public Member Functions | |
| (void) | - draw |
| (CCAction *) | - getActionByTag: |
| (int) | - numberOfRunningActions |
| (CCAction *) | - runAction: |
| (void) | - stopAction: |
| (void) | - stopActionByTag: |
| (void) | - stopAllActions |
| (void) | - unbind |
| (void) | - update: |
Static Public Member Functions | |
| (id) | + fog |
| (void) | + unbind |
Properties | |
| GLenum | attenuationMode |
| GLfloat | density |
| GLfloat | endDistance |
| ccColor4F | floatColor |
| BOOL | isRunning |
| GLenum | performanceHint |
| GLfloat | startDistance |
| BOOL | visible |
CC3Fog controls fog in the 3D world.
Fog color is controlled by the floatColor property, or via support for the CCRGBAProtocol protocol. However, be aware that alpha channels and opacity info are ignored by the OpenGL implementation of fog effects. See the notes of the color property for more info.
The style of attenuation imposed by the fog is set by the attenuationMode property. See the notes of that property for information about how fog attenuates visibility.
Using the performanceHint property, you can direct the GL engine to trade off between faster or nicer rendering quality.
| - (void) draw |
If the visible property is set to YES, draws the fog to the GL engine.
| + (id) fog |
Allocates and initializes an autoreleased instance.
| - (CCAction*) getActionByTag: | (int) | tag |
Gets an action from the running action list given its tag.
| - (int) numberOfRunningActions |
Returns the numbers of actions that are running plus the ones that are scheduled to run (actions in actionsToAdd and actions arrays).
Composable actions are counted as 1 action. Example: If you are running 1 Sequence of 7 actions, it will return 1. If you are running 7 Sequences of 2 actions, it will return 7.
| - (CCAction*) runAction: | (CCAction *) | action |
Executes an action, and returns the action that is executed.
This fog becomes the action's target.
| - (void) stopAction: | (CCAction *) | action |
Removes an action from the running action list.
| - (void) stopActionByTag: | (int) | tag |
Removes an action from the running action list given its tag.
| - (void) stopAllActions |
Removes all actions from the running action list.
| - (void) unbind |
Disables the rendering of fog in the GL engine.
| + (void) unbind |
Disables the rendering of fog in the GL engine.
| - (void) update: | (ccTime) | dt |
This method is invoked periodically when the fog is to be updated.
Typcially this method is invoked automatically from the CC3World instance via a scheduled update, but may also be invoked by some other periodic operation, or even directly by the application.
This method is invoked asynchronously to the frame rendering animation loop, to keep the processing of model updates separate from OpenGL ES drawing.
The dt argument gives the interval, in seconds, since the previous update. This value can be used to create realistic real-time motion that is independent of specific frame or update rates.
If this instance is not running, as indicated by the isRunning property, this method does nothing.
As implemented, this method does nothing. Subclasses may override.
This method is invoked automatically at each scheduled update. Usually, the application never needs to invoke this method directly.
- (GLenum) attenuationMode [read, write, assign] |
Indicates how the fog attenuates visibility with distance.
The value of this property must be one of the following sybolic constants: GL_LINEAR, GL_EXP or GL_EXP2.
When the value of this property is GL_LINEAR, the relative visibility of an object in the fog will be determined by the linear function ((e - z) / (e - s)), where s is the value of the start property, e is the value of the end property, and z is the distance of the object from the camera
When the value of this property is GL_EXP, the relative visibility of an object in the fog will be determined by the exponential function e^(-(d - z)), where d is the value of the density property and z is the distance of the object from the camera.
When the value of this property is GL_EXP2, the relative visibility of an object in the fog will be determined by the exponential function e^(-(d - z)^2), where d is the value of the density property and z is the distance of the object from the camera.
The initial value of this property is GL_EXP2.
- (GLfloat) density [read, write, assign] |
The density value used in the exponential functions.
This property is only used when the attenuationMode property is set to GL_EXP or GL_EXP2.
See the description of the attenuationMode for a discussion of how the exponential functions determine visibility.
The initial value of this property is 1.0.
- (GLfloat) endDistance [read, write, assign] |
The distance from the camera, at which linear attenuation ends.
Objects between this distance and the far clipping plane of the camera will be completely obscured.
This property is only used when the attenuationMode property is set to GL_LINEAR.
See the description of the attenuationMode for a discussion of how the linear function determine visibility.
The initial value of this property is 1.0.
- (ccColor4F) floatColor [read, write, assign] |
The color of the fog.
CC3Fog also supports the CCRGBAProtocol protocol, allowing the color of the fog to be manipulated by the CCTint interval action.
Although this color value, and the CCRGBAProtocol protocol support setting opacity, fog in OpenGL ES does not make use of opacity information, so any changes to the alpha channel of this property, or to the opacity property will be ignored.
The initial value of this property is kCCC4FBlack.
- (BOOL) isRunning [read, write, assign] |
Indicates whether the dynamic behaviour of this fog is enabled.
Setting this property affects both internal activities driven by the update process, and any CCActions controling this node. Setting this property to NO will effectively pause all update and CCAction behaviour on the node. Setting this property to YES will effectively resume the update and CCAction behaviour.
- (GLenum) performanceHint [read, write, assign] |
Indicates how the GL engine should trade off between rendering quality and speed.
The value of this property should be one of GL_FASTEST, GL_NICEST, or GL_DONT_CARE.
The initial value of this property is GL_DONT_CARE.
- (GLfloat) startDistance [read, write, assign] |
The distance from the camera, at which linear attenuation starts.
Objects between this distance and the near clipping plane of the camera will be completly visible.
This property is only used when the attenuationMode property is set to GL_LINEAR.
See the description of the attenuationMode for a discussion of how the linear function determine visibility.
The initial value of this property is 0.0.
- (BOOL) visible [read, write, assign] |
Controls whether the fog should be drawn into the world.
The initial value of this property is YES.
1.7.2