怎样在程序中使用vgPicker移动物体

类型：整理 | 来自：86CG | 时间：2007-11-29 | 点击：

#include
#include "vg.h"
#include "pf.h"
#include "assert.h"

vgPicker    *picker    = NULL;
vgObserver *mainObs   = NULL;
vgChannel   *mainChan = NULL;
vgEnv       *mainEnv   = NULL;
vgWindow    *mainWin   = NULL;
vgGfx       *mainGfx   = NULL;
vgScene     *mainScn   = NULL;

void setSystemPointers();
void createPicker();
void userUpdates();
void checkPickEvent();

void setSystemPointers(){
// ####################################################
// # 获取系统的主要指针，注意必须在vgConfigSys()之后调用
// #
// ####################################################

    mainWin = vgGetWin( 0 );
    assert(mainWin);

    mainObs = vgGetObserv( 0 );
    assert(mainObs );

    mainChan = vgGetObservChan( mainObs, 0 );
    assert(mainChan);

    mainGfx = vgGetObservGfx( mainObs );
    assert(mainEnv);

    mainEnv = vgGetEnv( 0 );
    assert(mainEnv);

    mainScn = vgGetScene(0);
    assert(mainScn);

}

void createPicker(){
// ########################################
// # 创建一个vgPicker
// #
// ########################################

    picker = vgNewPicker();
    assert( picker );
    vgName( picker, "example_picker" );

    //
    // 指定vgPicker起作用的场景和通道
    //
    vgPickerScene( picker, mainScn );
    vgPickerChannel( picker, mainChan );

    //
    // 设置vgPicker属性，选择物体红色显示
    //
    vgPickerHighLightColor( picker, 1.0f, 0.0f, 0.0f );
    vgProp( picker, VGPICK_TRANSFORM,     VGPICK_TRANSLATE   );
vgProp( picker, VGPICK_TRANSCOORDS, VGPICK_OBJECT_AXES );
vgProp( picker, VGPICK_HL_LEVEL, VGPICK_OBJECT );
    vgProp( picker, VGPICK_HL_STYLE,       VGPICK_HL_LINE     );
    vgProp( picker, VGPICK_TERRAIN_CLAMP, VG_OFF             );
    vgProp( picker, VGPICK_TRANSOVERRIDE, VG_OFF             );
    vgProp( picker, VGPICK_DISPLAY_STDOUT, VG_OFF             );
    vgProp( picker, VGPICK_MULTIPLE_PICKS, VG_OFF             );
    vgProp( picker, VGPICK_AUTOTRANSFORM, VG_OFF             );
    vgProp( picker, VGPICK_TRACKPLANE,     VGPICK_TRACK_XY    );
    vgProp( picker, VGPICK_AUTOTRACKPLANE, VG_OFF             );
    vgProp( picker, VGPICK_DRAG_FACTOR,    1.0f               );
    vgProp( picker, VGPICK_RENDER_ISECT,   VG_OFF             );

    //
    // 设置vgPicker的相交矢量
    //
    vgPickerClampIsector( picker, 0x10000000 );
    vgPickerIsector( picker, 0x10000000 );

    // 启用vgPicker
    vgProp( picker, VGCOMMON_ENABLED, VG_ON );

}

void checkPickEvent(){
// ###################################################
// # 判断vgPicker当前的动作
// #
// #
// ###################################################
static vgMouse mouse;
static vgPosition *pos = NULL;
    if( pos == NULL ){
      pos = vgNewPos();
       assert( pos );
        }
    vgGetMouse( &mouse );

    // 鼠标左键：拾取或取消拾取物体
   if( mouse.lb && !mouse.mb && !mouse.rb ) {
        vgGetPos( obs, pos );
        vgPerformPickProcessing( picker, pos) ;
        }

    // 拖拽鼠标右键：在指定的平面上移动选定的物体
    if( !mouse.lb && !mouse.mb && mouse.rb ) {
        vgGetPos( obs, pos );
          vgPickerDoMouseTransform( picker, pos);
        }

}

void userUpdates( ) {
// ############################################
// # 响应用户的键盘输入：
// # 1——在XY平面上移动物体（默认情况）
// # 2——在XZ平面上移动物体
// # 3——在YZ平面上移动物体
// ############################################
int key   = 0;

    while( (key = vgGetWinKey( mainWin )) != 0 ) {

        switch( key ) {

           case '1':
                vgProp( picker, VGPICK_TRACKPLANE, VGPICK_TRACK_XY );
                break;

            case '2':
                vgProp( picker, VGPICK_TRACKPLANE, VGPICK_TRACK_XZ );
                break;

            case '3':
                vgProp( picker, VGPICK_TRACKPLANE, VGPICK_TRACK_YZ );
                break;


            default: break;

            }
        }

}

int main(int argc, char* argv[]) {


    if( argc \n", argv[0] );
       exit ( -1 );
       }

    vgInitSys();
    vgDefineSys( argv[1] );
    vgConfigSys();

    setSystemPointers();
    createPicker();

    //
    //设置物体mask掩码与vgPicker相一致，使得所有的物体都可以被选中
    //
    for( int i= 0; i < vgGetNumObj(), i++ ){

        vgObject *obj     = vgGetObj(i);
        unsigned int mask = vgGetObjClass( obj );
        mask |= vgGetPickerIsector( picker );
        vgObjClass( obj, mask );
        }

    while( true ) {

        vgSyncFrame();
        vgFrame();
        userUpdates();
        checkPickEvent();
        }

return 0;
}

(完)

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