DXUT框架剖析（11）

DXUT统计函数

函数
描述

DXUTGetFPS
获取当前每秒提交的帧数

DXUTGetFrameStats
获取一个指向字符串的指针，该字符串包括每秒帧数、分辨率、后台缓冲区格式、深度缓冲区格式。

DXUTGetDeviceStats
获取一个指向字符串的指针，该字符串包括当前设备类型、顶点运算行为和设备名。

DXUTGetFPS

Get the current number of frames being presented per second.

 FLOAT DXUTGetFPS()  ;

Parameters
None.

Return Values
The current number of frames being presented per second.

DXUTGetFrameStats

Get a pointer to a string containing the current number of frames per second (optionally), resolution, back buffer format, and depth stencil format.

 LPCWSTR DXUTGetFrameStats(
 bool   bIncludeFPS
 )  ;

Parameters

bIncludeFPS

[in] If true, the string returned will contain the frames per second. Otherwise, it will not.

Return Values
Pointer to a string containing the current number of frames per second (optionally), resolution, back buffer format, and depth stencil format.

DXUTGetDeviceStats

Get a pointer to a string containing the current device type, vertex processing behavior, and device name.

 LPCWSTR DXUTGetDeviceStats()  ;

Parameters
None.

Return Values
Pointer to a string containing the current device type, vertex processing behavior, and device name.

DXUT时间函数

函数
描述

DXUTGetTime
获取当前时间（秒）

DXUTGetElapsedTime
获取从上一帧到当前帧所经过的时间

DXUTSetConstantFrameTime
启用或禁用固定帧时间

DXUTGetTime

Get the current time, in seconds.

 DOUBLE DXUTGetTime()  ;

Parameters
None.

Return Values
The current time, in seconds.

Remarks
DXUT internally uses the best practices for high resolution timing information as described in the "Game Timing and Multicore Processors" article in the DirectX SDK.

DXUTGetElapsedTime

Get the time elapsed since the last frame.

 FLOAT DXUTGetElapsedTime()  ;

Parameters
None.

Return Values
Time elapsed, in seconds, since the last frame.

Remarks
DXUT internally uses the best practices for high resolution timing information as described in the "Game Timing and Multicore Processors" article in the DirectX SDK.

DXUTSetConstantFrameTime

Enables or disables a constant frame time.

 HRESULT DXUTSetConstantFrameTime(
 BOOL   bEnabled   ,
 FLOAT   fTimePerFrame
 )  ;

Parameters

bEnabled

[in] If TRUE, a constant frame time will be enabled.

fTimePerFrame

[in] Time per frame, in seconds. The default value is 0.0333f, so the fTime parameter of LPDXUTCALLBACKFRAMEMOVE and the render callback functions will advance one second for every 30 frames.

Return Values
If the function succeeds, the return value is S_OK. If the function fails, the return value can be one of the error codes in DXUTERR.

Remarks
This function simulates a fixed-frame rate render loop by sending a constant value for elapsed time to the LPDXUTCALLBACKFRAMEMOVE and render callback functions. The default rate is one second for every 30 frames. The application itself will continue to render at an unregulated rate (which may be far higher than the specified frame rate).

This function is useful for saving the rendered output to a video format for playback, allowing animation at a rate independent of the actual rate at which frames were rendered.

DXUT计时器函数

函数
描述

DXUTSetTimer
添加一个新的计时器

DXUTKillTimer
卸载一个已有的计时器

DXUTSetTimer

Starts a DXUT timer that will trigger a callback function at regular intervals.

 HRESULT DXUTSetTimer(
 LPDXUTCALLBACKTIMER   pCallbackTimer   ,
 FLOAT   fTimeoutInSecs   ,
 UINT *   pnIDEvent   ,
 void *   pCallbackUserContext
 )  ;

Parameters

pCallbackTimer

[in] Pointer to a timer callback function. The callback function is to be called at the specified fTimeoutInSecs timeout intervals. May not be NULL.

fTimeoutInSecs

[in] Interval, in seconds, between successive calls to the timer callback function. The default value is 1.0f.

pnIDEvent

[in] Optional pointer to a variable to receive the event ID for the new timer. This event ID will be passed to the timer callback function to indicate which timer generated the event, allowing the application to use a single callback function for multiple timers. The default value is NULL.

pCallbackUserContext

[in] Pointer to a user-defined value which is passed to the callback function. Typically used by an application to pass a pointer to a data structure that provides context information for the callback function. The default value is NULL

Return Values
If the function succeeds, the return value is S_OK. If the function fails, the return value can be one of the error codes in DXUTERR.

Remarks
Timers created with DXUTSetTimer can be destroyed with DXUTKillTimer.

LPDXUTCALLBACKTIMER

A timer to be called at specified time intervals by DXUT.

 VOID LPDXUTCALLBACKTIMER(
 UINT   idEvent   ,
 void*   pUserContext
 )  ;

Parameters

idEvent

[in] Specifies a nonzero timer event ID. Indicates which timer generated the event, allowing the application to use a single callback function for multiple timers.

pUserContext

[in] Pointer to a user-defined value which is passed to the callback function. Typically used by an application to pass a pointer to a data structure that provides context information for the callback function. The default value is NULL

Return Values
No return value.

Remarks
DXUT will call this function at the start of the frame, before calling LPDXUTCALLBACKFRAMEMOVE or LPDXUTCALLBACKD3D10FRAMERENDER.

DXUTKillTimer

Uninstalls an existing timer.

 HRESULT DXUTKillTimer(
 UINT   nIDEvent
 )  ;

Parameters

nIDEvent

[in] The event ID for the timer being destroyed. This ID is provided to the application by the DXUTSetTimer method.

Return Values
If the function succeeds, the return value is S_OK. If the function fails, the return value can be one of the error codes in DXUTERR.

Remarks
Timers created with DXUTSetTimer can be destroyed with DXUTKillTimer .