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' ________________________________________________________________________
' TRUEVISION8 (web: http://www.truevision3d.com)
' ????????????????????????????????????
' Tutorial 12 : Get a landscape position
' ??????
' Description : In this 12th tutorial, we go back to a basic landscape
' ?????? loading and we add a collision check to get the impact
' point with the mouse.
'
' Force explicit declarations
Option Explicit
' We declare TVEngine.
Private TV8 As TVEngine
' New : to get the mouse pointer position, we have to check if
' there was a collision with the mouse position and the landscape.
' For this, we use the TV8 collision detection object.
Private CollisionResult As TVCollisionResult
' We declare the landscape
Private Land As TVLandscape
' The texture factory
Private TextureFactory As TVTextureFactory
' We the declare the scene
Private Scene As TVScene
' We declare the input engine.
Private InputEngine As TVInputEngine
' The loop.
Private DoLoop As Boolean
' We are going to use camera (point of view) angles, as well as the
' camera position and look at vectors.
Private sngPositionX As Single
Private sngPositionY As Single
Private sngPositionZ As Single
Private snglookatX As Single
Private snglookatY As Single
Private snglookatZ As Single
' We could have done this in many ways, but we added some smoothing to
' the movement se we need to declare two additional variables.
Private sngWalk As Single
Private sngStrafe As Single
Private Sub cmdQuit_Click()
' We have clicked on the "Quit" button, so we change the DoLoop.
DoLoop = False
End Sub
Private Sub Form_Load()
' We have to create the TV8 object before anything else.
Set TV8 = New TVEngine
' Set the search directory of Textures, Objects, ...
TV8.SetSearchDirectory App.Path
' We initialize TV8 in the picture box of the form.
TV8.Init3DWindowedMode Picture1.hWnd
' We want to see the FPS.
TV8.DisplayFPS = True
' We create the input object.
Set InputEngine = New TVInputEngine
' We create the scene (the world).
Set Scene = New TVScene
' New : we load a mouse pointer texture. The cursor you
' are seeing normally is the Windows cursor and it's
' position is NOT the game's mouse pointer position.
'为场景加载光标
Scene.LoadCursor "..\..\..\Media\pointer.bmp", TV_COLORKEY_BLACK, 32, 16
' Set background color
Scene.SetSceneBackGround 0.7, 0.7, 0.3
' Create the texture factory
Set TextureFactory = New TVTextureFactory
' Land generation
Set Land = New TVLandscape
' Generate the height of the land from the grayscale of the image.
Land.GenerateHugeTerrain "..\..\..\Media\heightmap.jpg", TV_PRECISION_LOW, 8, 8, 0, 0, True
' Then, we load the land texture.
TextureFactory.LoadTexture "..\..\..\Media\sand.jpg", "LandTexture"
' We assign a texture to that land.
Land.SetTexture GetTex("LandTexture")
' We set the camera vectors (the position will be automatically
' updated in the checks)
snglookatX = 150
snglookatZ = 550
' We set the initial values of movement
sngWalk = 0
sngStrafe = 0
' We pop the form over everything else.
Form1.Show
' We start the main loop.
DoLoop = True
Main_Loop
End Sub
Private Sub Form_Unload(Cancel As Integer)
' The user asked to quit but clicked on the 'X' button at up right.
DoLoop = False
' And ask to quit.
Main_Quit
End Sub
Private Sub Main_Loop()
' The main loop
Do
' Let us the capacity to use buttons of the form.
DoEvents
' Check the input
Check_Input
' check and update the movement
Check_Movement
' Clear the the last frame.
TV8.Clear
' We render the landscape.
Land.Render True
' We display everything that we have rendered
TV8.RenderToScreen
'We loop all of this until the DoLoop isn't True.
Loop Until DoLoop = False
' We ask to quit.
Main_Quit
End Sub
Private Sub Check_Input()
' Check if we pressed the UP arrow key, if so, then we are
' walking forward.
If InputEngine.IsKeyPressed(TV_KEY_UP) = True Then
sngWalk = 1
' If we are not walking forward, maybe we are walking backward
' by using the DOWN arrow? If so, set walk speed to negative.
ElseIf InputEngine.IsKeyPressed(TV_KEY_DOWN) = True Then
sngWalk = -1
End If
' Check if we pressed the LEFT arrow key, if so, then strafe
' on the left.
If InputEngine.IsKeyPressed(TV_KEY_LEFT) = True Then
sngStrafe = 1
' If we are not strafing left, maybe we want to strafe to the
' right, using the RIGHT arrow? If so, set strafe to negative.
ElseIf InputEngine.IsKeyPressed(TV_KEY_RIGHT) = True Then
sngStrafe = -1
End If
' New : we check the mouse by using an other method. We
' are going to get the absolute mouse status.
'获得鼠标绝对坐标值
Dim tmpMouseX As Long, tmpMouseY As Long
InputEngine.GetAbsMouseState tmpMouseX, tmpMouseY
' New : we set the collision object which will be
' used for the mouse pick on the scene's landscape
'设置撞击对象，使用鼠标拾取地面坐标值
Set CollisionResult = Scene.MousePicking(tmpMouseX, tmpMouseY, TV_COLLIDE_LANDSCAPE, TV_TESTTYPE_ACCURATETESTING)
' Check if we did have a collision with the landscape.
' If so, pass the collision point to the list box
' on the form.
'判断如果鼠标碰到地面的话，则显示其坐标值
If CollisionResult.IsCollision Then
txtCollision(0) = "X:" & CollisionResult.GetImpactPoint.x
txtCollision(1) = "Y:" & Land.GetHeight(CollisionResult.GetImpactPoint.x, CollisionResult.GetImpactPoint.z)
txtCollision(2) = "Z:" & CollisionResult.GetImpactPoint.z
End If
End Sub
Private Sub Check_Movement()
' Okay, now for the smothing of the movement... Update
' the forward and backward (walk) movement.
Select Case sngWalk
Case Is > 0
sngWalk = sngWalk - 0.005 * TV8.TimeElapsed
If sngWalk < 0 Then sngWalk = 0
Case Is < 0
sngWalk = sngWalk + 0.005 * TV8.TimeElapsed
If sngWalk > 0 Then sngWalk = 0
End Select
' Now, we update the left and right (strafe) movement.
Select Case sngStrafe
Case Is > 0
sngStrafe = sngStrafe - 0.005 * TV8.TimeElapsed
If sngStrafe < 0 Then sngStrafe = 0
Case Is < 0
sngStrafe = sngStrafe + 0.005 * TV8.TimeElapsed
If sngStrafe > 0 Then sngStrafe = 0
End Select
' Update the vectors using the angles and positions.
snglookatX = snglookatX + sngWalk * 5
snglookatZ = snglookatZ + sngStrafe * 5
snglookatY = Land.GetHeight(snglookatX, snglookatZ)
' We update the look at position.
sngPositionX = snglookatX - 150
sngPositionZ = snglookatZ
sngPositionY = Land.GetHeight(sngPositionX, sngPositionZ) + 50
' With the new values of the camera vectors (position and
' look at), we update the scene's camera.
Scene.SetCamera sngPositionX, sngPositionY, sngPositionZ, snglookatX, snglookatY, snglookatZ
End Sub
Private Sub Main_Quit()
' We want to quit the project, so we start by destroyng
' the texture factory.
Set TextureFactory = Nothing
' We destroy the collision object
Set CollisionResult = Nothing
' We destroy the land object.
Set Land = Nothing
' Don't forget to destroy the inputengine object...
Set InputEngine = Nothing
' Then, we destroy the scene object.
Set Scene = Nothing
' We finish the frenetic destroy with the TV8 object.
Set TV8 = Nothing
' We end the application.
End
End Sub
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