fix(view): Introduce PRESERVE_RETAIL_SCRIPTED_CAMERA and fix or improve camera offset and zoom calculations (TheSuperHackers#2524)

Author: xezon

Core/GameEngine/Include/Common/GameDefines.h

@@ -27,6 +27,10 @@
 #define PRESERVE_RETAIL_BEHAVIOR (1) // Retain behavior present in retail Generals 1.08 and Zero Hour 1.04
 #endif
 
+#ifndef PRESERVE_RETAIL_SCRIPTED_CAMERA
+#define PRESERVE_RETAIL_SCRIPTED_CAMERA (1) // Retain scripted camera behavior present in retail Generals 1.08 and Zero Hour 1.04
+#endif
+
 #ifndef RETAIL_COMPATIBLE_CRC
 #define RETAIL_COMPATIBLE_CRC (1) // Game is expected to be CRC compatible with retail Generals 1.08, Zero Hour 1.04
 #endif

Core/GameEngineDevice/Include/W3DDevice/GameClient/W3DView.h

@@ -275,18 +275,27 @@ class W3DView : public View, public SubsystemInterface
 	Bool		m_cameraHasMovedSinceRequest;					///< If true, throw out all saved locations
 	VecPosRequests	m_locationRequests;		///< These are cached. New requests are added here
 
-	Coord3D m_cameraOffset;													///< offset for camera from view center
-	Coord3D m_previousLookAtPosition;													///< offset for camera from view center
+	Coord3D m_previousLookAtPosition;
 	Coord2D m_scrollAmount;													///< scroll speed
 	Real m_scrollAmountCutoffSqr;										///< scroll speed at which we do not adjust height
 
 	Real m_groundLevel;															///< height of ground.
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
+	// TheSuperHackers @tweak Uses the initial ground level for preserving the original look of the scripted camera,
+	// because alterations to the ground level do affect the positioning in subtle ways.
+	Real m_initialGroundLevel;
+#endif
 
 	Region2D m_cameraAreaConstraints; ///< Camera should be constrained to be within this area
 	Bool m_cameraAreaConstraintsValid; ///< If false, recalculates the camera area constraints in the next render update
 	Bool m_recalcCameraConstraintsAfterScrolling; ///< Recalculates the camera area constraints after the user has moved the camera
 	Bool m_recalcCamera; ///< Recalculates the camera transform in the next render update
 
+	Real getCameraOffsetZ() const;
+	Real getDesiredHeight(Real x, Real y) const;
+	Real getDesiredZoom(Real x, Real y) const;
+	Real getMaxHeight(Real x, Real y) const;
+	Real getMaxZoom(Real x, Real y) const;
 	void setCameraTransform(); ///< set the transform matrix of m_3DCamera, based on m_pos & m_angle
 	void buildCameraPosition(Vector3 &sourcePos, Vector3 &targetPos);
 	void buildCameraTransform(Matrix3D *transform, const Vector3 &sourcePos, const Vector3 &targetPos); ///< calculate (but do not set) the transform matrix of m_3DCamera, based on m_pos & m_angle

Core/GameEngineDevice/Source/W3DDevice/GameClient/W3DView.cpp

@@ -142,9 +142,9 @@ W3DView::W3DView()
 	m_3DCamera = nullptr;
 	m_2DCamera = nullptr;
 	m_groundLevel = 10.0f;
-	m_cameraOffset.z = TheGlobalData->m_cameraHeight;
-	m_cameraOffset.y = -(m_cameraOffset.z / tan(TheGlobalData->m_cameraPitch * (PI / 180.0)));
-	m_cameraOffset.x = -(m_cameraOffset.y * tan(TheGlobalData->m_cameraYaw * (PI / 180.0)));
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
+	m_initialGroundLevel = m_groundLevel;
+#endif
 
 	m_viewFilterMode = FM_VIEW_DEFAULT;
 	m_viewFilter = FT_VIEW_DEFAULT;
@@ -261,9 +261,11 @@ void W3DView::buildCameraPosition( Vector3& sourcePos, Vector3& targetPos )
 	pos.x += m_shakeOffset.x;
 	pos.y += m_shakeOffset.y;
 
-	sourcePos.X = m_cameraOffset.x;
-	sourcePos.Y = m_cameraOffset.y;
-	sourcePos.Z = m_cameraOffset.z;
+	// TheSuperHackers @info The default pitch affects the look-at distance to the target.
+	// This is strange math which would need special attention when changed.
+	sourcePos.Z = getCameraOffsetZ();
+	sourcePos.Y = -(sourcePos.Z / tan(TheGlobalData->m_cameraPitch * (PI / 180.0)));
+	sourcePos.X = -(sourcePos.Y * tan(TheGlobalData->m_cameraYaw * (PI / 180.0)));
 
 	// set position of camera itself
 	if (m_useRealZoomCam) //WST 10/10/2002 Real Zoom using FOV
@@ -358,7 +360,7 @@ void W3DView::buildCameraTransform( Matrix3D *transform, const Vector3 &sourcePo
 {
 	//m_3DCamera->Set_View_Plane(DEG_TO_RADF(50.0f));
 	//DEBUG_LOG(("zoom %f, SourceZ %f, posZ %f, groundLevel %f CamOffZ %f",
-	//			zoom, sourcePos.Z, pos.z, groundLevel,m_cameraOffset.z));
+	//			zoom, sourcePos.Z, pos.z, groundLevel, getCameraOffsetZ()));
 
 	// build new camera transform
 	transform->Make_Identity();
@@ -422,8 +424,7 @@ void W3DView::buildCameraTransform( Matrix3D *transform, const Vector3 &sourcePo
 // TheSuperHackers @info Original logic responsible for zooming the camera to the desired height.
 Bool W3DView::zoomCameraToDesiredHeight()
 {
-	const Real desiredHeight = (m_terrainHeightAtPivot + m_heightAboveGround);
-	const Real desiredZoom = desiredHeight / m_cameraOffset.z;
+	const Real desiredZoom = getDesiredZoom(m_pos.x, m_pos.y);
 	const Real adjustZoom = desiredZoom - m_zoom;
 	if (fabs(adjustZoom) >= 0.001f)
 	{
@@ -640,6 +641,67 @@ void W3DView::getPickRay(const ICoord2D *screen, Vector3 *rayStart, Vector3 *ray
 	*rayEnd += *rayStart;	//get point on far clip plane along ray from camera.
 }
 
+//-------------------------------------------------------------------------------------------------
+//-------------------------------------------------------------------------------------------------
+Real W3DView::getCameraOffsetZ() const
+{
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
+	// TheSuperHackers @info xezon 04/12/2025 It is necessary to use the initial ground level for the
+	// scripted camera height to preserve the original look of it. Otherwise the forward distance
+	// of the camera will slightly change the view pitch.
+	if (!m_isUserControlled)
+	{
+		return m_initialGroundLevel + TheGlobalData->m_cameraHeight;
+	}
+#endif
+
+	return m_groundLevel + TheGlobalData->m_maxCameraHeight;
+}
+
+//-------------------------------------------------------------------------------------------------
+//-------------------------------------------------------------------------------------------------
+Real W3DView::getDesiredHeight(Real x, Real y) const
+{
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
+	// TheSuperHackers @info xezon 06/12/2025 The height above ground must be relative to the current
+	// terrain height because the ground level is not updated for it.
+	if (!m_isUserControlled)
+	{
+		return getHeightAroundPos(x, y) + m_heightAboveGround;
+	}
+#endif
+
+	return m_groundLevel + m_heightAboveGround;
+}
+
+//-------------------------------------------------------------------------------------------------
+//-------------------------------------------------------------------------------------------------
+Real W3DView::getMaxHeight(Real x, Real y) const
+{
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
+	if (!m_isUserControlled)
+	{
+		return getHeightAroundPos(x, y) + m_maxHeightAboveGround;
+	}
+#endif
+
+	return m_groundLevel + m_maxHeightAboveGround;
+}
+
+//-------------------------------------------------------------------------------------------------
+//-------------------------------------------------------------------------------------------------
+Real W3DView::getDesiredZoom(Real x, Real y) const
+{
+	return getDesiredHeight(x, y) / getCameraOffsetZ();
+}
+
+//-------------------------------------------------------------------------------------------------
+//-------------------------------------------------------------------------------------------------
+Real W3DView::getMaxZoom(Real x, Real y) const
+{
+	return getMaxHeight(x, y) / getCameraOffsetZ();
+}
+
 //-------------------------------------------------------------------------------------------------
 /** set the transform matrix of m_3DCamera, based on m_pos & m_angle */
 //-------------------------------------------------------------------------------------------------
@@ -1423,7 +1485,7 @@ void W3DView::update()
 	// ensures that the view can reach and see all areas of the map, and especially the bottom map border.
 
 	m_terrainHeightAtPivot = getHeightAroundPos(m_pos.x, m_pos.y);
-	m_currentHeightAboveGround = m_cameraOffset.z * m_zoom - m_terrainHeightAtPivot;
+	m_currentHeightAboveGround = getCameraOffsetZ() * m_zoom - m_terrainHeightAtPivot;
 
 	if (m_okToAdjustHeight)
 	{
@@ -2055,7 +2117,7 @@ void W3DView::setHeightAboveGround(Real z)
 void W3DView::setZoom(Real z)
 {
 	m_heightAboveGround = m_maxHeightAboveGround * z;
-	m_zoom = z;
+	m_zoom = getDesiredZoom(m_pos.x, m_pos.y);
 
 	stopDoingScriptedCamera();
 	m_CameraArrivedAtWaypointOnPathFlag = false;
@@ -2068,18 +2130,8 @@ void W3DView::setZoom(Real z)
 void W3DView::setZoomToDefault()
 {
 	// default zoom has to be max, otherwise players will just zoom to max always
-
-	// terrain height + desired height offset == cameraOffset * actual zoom
-	// find best approximation of max terrain height we can see
-	Real terrainHeightMax = getHeightAroundPos(m_pos.x, m_pos.y);
-
-	Real desiredHeight = (terrainHeightMax + m_maxHeightAboveGround);
-	Real desiredZoom = desiredHeight / m_cameraOffset.z;
-
-	//DEBUG_LOG(("W3DView::setZoomToDefault() Current zoom: %g  Desired zoom: %g", m_zoom, desiredZoom));
-
-	m_zoom = desiredZoom;
 	m_heightAboveGround = m_maxHeightAboveGround;
+	m_zoom = getMaxZoom(m_pos.x, m_pos.y);
 
 	stopDoingScriptedCamera();
 	m_CameraArrivedAtWaypointOnPathFlag = false;
@@ -2448,10 +2500,14 @@ void W3DView::initHeightForMap()
 {
 	resetPivotToGround();
 
-	m_cameraOffset.z = m_groundLevel+TheGlobalData->m_cameraHeight;
-	m_cameraOffset.y = -(m_cameraOffset.z / tan(TheGlobalData->m_cameraPitch * (PI / 180.0)));
-	m_cameraOffset.x = -(m_cameraOffset.y * tan(TheGlobalData->m_cameraYaw * (PI / 180.0)));
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
+	// jba - starting ground level can't exceed this height.
+	constexpr const Real MAX_GROUND_LEVEL = 120.0f;
+	const Real accurateGroundLevel = TheTerrainLogic->getGroundHeight(m_pos.x, m_pos.y);
+	m_initialGroundLevel = min(MAX_GROUND_LEVEL, accurateGroundLevel);
+#endif
 }
+
 //-------------------------------------------------------------------------------------------------
 //-------------------------------------------------------------------------------------------------
 void W3DView::resetPivotToGround( void )
@@ -2638,22 +2694,14 @@ void W3DView::cameraModFinalZoom( Real finalZoom, Real easeIn, Real easeOut )
 {
 	if (hasScriptedState(Scripted_Rotate))
 	{
-		Real terrainHeightMax = getHeightAroundPos(m_pos.x, m_pos.y);
-		Real maxHeight = (terrainHeightMax + m_maxHeightAboveGround);
-		Real maxZoom = maxHeight / m_cameraOffset.z;
-
 		Real time = (m_rcInfo.numFrames + m_rcInfo.numHoldFrames - m_rcInfo.curFrame)*TheW3DFrameLengthInMsec;
-		zoomCamera( finalZoom*maxZoom, time, time*easeIn, time*easeOut );
+		zoomCamera( finalZoom*getMaxZoom(m_pos.x, m_pos.y), time, time*easeIn, time*easeOut );
 	}
 	if (hasScriptedState(Scripted_MoveOnWaypointPath))
 	{
 		Coord3D pos = m_mcwpInfo.waypoints[m_mcwpInfo.numWaypoints];
-		Real terrainHeightMax = getHeightAroundPos(pos.x, pos.y);
-		Real maxHeight = (terrainHeightMax + m_maxHeightAboveGround);
-		Real maxZoom = maxHeight / m_cameraOffset.z;
-
 		Real time = m_mcwpInfo.totalTimeMilliseconds - m_mcwpInfo.elapsedTimeMilliseconds;
-		zoomCamera( finalZoom*maxZoom, time, time*easeIn, time*easeOut );
+		zoomCamera( finalZoom*getMaxZoom(pos.x, pos.y), time, time*easeIn, time*easeOut );
 	}
 }
 
@@ -2888,13 +2936,7 @@ void W3DView::resetCamera(const Coord3D *location, Int milliseconds, Real easeIn
 	// m_mcwpInfo.cameraAngle[2] = m_defaultAngle;
 	View::setAngle(m_mcwpInfo.cameraAngle[0]);
 
-	// terrain height + desired height offset == cameraOffset * actual zoom
-	// find best approximation of max terrain height we can see
-	Real terrainHeightMax = getHeightAroundPos(location->x, location->y);
-	Real desiredHeight = (terrainHeightMax + m_maxHeightAboveGround);
-	Real desiredZoom = desiredHeight / m_cameraOffset.z;
-
-	zoomCamera( desiredZoom, milliseconds, easeIn, easeOut );	// this isn't right... or is it?
+	zoomCamera( getMaxZoom(location->x, location->y), milliseconds, easeIn, easeOut );
 
 	pitchCamera( 1.0f, milliseconds, easeIn, easeOut );
 }
@@ -3194,6 +3236,9 @@ void W3DView::setUserControlled(Bool value)
 	if (m_isUserControlled != value)
 	{
 		m_isUserControlled = value;
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
+		m_zoom = getDesiredZoom(m_pos.x, m_pos.y);
+#endif
 	}
 }
 
@@ -3248,9 +3293,6 @@ void W3DView::moveAlongWaypointPath(Real milliseconds)
 		View::setAngle(m_mcwpInfo.cameraAngle[m_mcwpInfo.numWaypoints]);
 
 		m_groundLevel = m_mcwpInfo.groundHeight[m_mcwpInfo.numWaypoints];
-		/////////////////////m_cameraOffset.z = m_groundLevel+TheGlobalData->m_cameraHeight;
-		m_cameraOffset.y = -(m_cameraOffset.z / tan(TheGlobalData->m_cameraPitch * (PI / 180.0)));
-		m_cameraOffset.x = -(m_cameraOffset.y * tan(TheGlobalData->m_cameraYaw * (PI / 180.0)));
 
 		Coord3D pos = m_mcwpInfo.waypoints[m_mcwpInfo.numWaypoints];
 		pos.z = 0;
@@ -3324,9 +3366,6 @@ void W3DView::moveAlongWaypointPath(Real milliseconds)
 
 	m_groundLevel = m_mcwpInfo.groundHeight[m_mcwpInfo.curSegment]*factor1 +
 			m_mcwpInfo.groundHeight[m_mcwpInfo.curSegment+1]*factor2;
-	//////////////m_cameraOffset.z = m_groundLevel+TheGlobalData->m_cameraHeight;
-	m_cameraOffset.y = -(m_cameraOffset.z / tan(TheGlobalData->m_cameraPitch * (PI / 180.0)));
-	m_cameraOffset.x = -(m_cameraOffset.y * tan(TheGlobalData->m_cameraYaw * (PI / 180.0)));
 
 	Coord3D start, mid, end;
 	if (factor<0.5) {

Generals/Code/GameEngine/Include/Common/GlobalData.h

@@ -184,7 +184,9 @@ class GlobalData : public SubsystemInterface
 	Real m_viewportHeightScale; // The height scale of the tactical view ranging 0..1. Used to hide the world behind the Control Bar.
 	Real m_cameraPitch;
 	Real m_cameraYaw;
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
 	Real m_cameraHeight;
+#endif
 	Real m_maxCameraHeight;
 	Real m_minCameraHeight;
 	Real m_terrainHeightAtEdgeOfMap;

Generals/Code/GameEngine/Source/Common/GlobalData.cpp

@@ -182,7 +182,9 @@ GlobalData* GlobalData::m_theOriginal = nullptr;
 	{ "ViewportHeightScale", INI::parseReal, nullptr, offsetof( GlobalData, m_viewportHeightScale ) },
 	{ "CameraPitch",								INI::parseReal,				nullptr,			offsetof( GlobalData, m_cameraPitch ) },
 	{ "CameraYaw",									INI::parseReal,				nullptr,			offsetof( GlobalData, m_cameraYaw ) },
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
 	{ "CameraHeight",								INI::parseReal,				nullptr,			offsetof( GlobalData, m_cameraHeight ) },
+#endif
 	{ "MaxCameraHeight",						INI::parseReal,				nullptr,			offsetof( GlobalData, m_maxCameraHeight ) },
 	{ "MinCameraHeight",						INI::parseReal,				nullptr,			offsetof( GlobalData, m_minCameraHeight ) },
 	{ "TerrainHeightAtEdgeOfMap",					INI::parseReal,				nullptr,			offsetof( GlobalData, m_terrainHeightAtEdgeOfMap ) },
@@ -838,7 +840,9 @@ GlobalData::GlobalData()
 
 	m_cameraPitch = 0.0f;
 	m_cameraYaw = 0.0f;
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
 	m_cameraHeight = 0.0f;
+#endif
 	m_minCameraHeight = 100.0f;
 	m_maxCameraHeight = 300.0f;
 	m_terrainHeightAtEdgeOfMap = 0.0f;

GeneralsMD/Code/GameEngine/Include/Common/GlobalData.h

@@ -185,7 +185,9 @@ class GlobalData : public SubsystemInterface
 	Real m_viewportHeightScale; // The height scale of the tactical view ranging 0..1. Used to hide the world behind the Control Bar.
 	Real m_cameraPitch;
 	Real m_cameraYaw;
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
 	Real m_cameraHeight;
+#endif
 	Real m_maxCameraHeight;
 	Real m_minCameraHeight;
 	Real m_terrainHeightAtEdgeOfMap;

GeneralsMD/Code/GameEngine/Source/Common/GlobalData.cpp

@@ -182,7 +182,9 @@ GlobalData* GlobalData::m_theOriginal = nullptr;
 	{ "ViewportHeightScale", INI::parseReal, nullptr, offsetof( GlobalData, m_viewportHeightScale ) },
 	{ "CameraPitch",								INI::parseReal,				nullptr,			offsetof( GlobalData, m_cameraPitch ) },
 	{ "CameraYaw",									INI::parseReal,				nullptr,			offsetof( GlobalData, m_cameraYaw ) },
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
 	{ "CameraHeight",								INI::parseReal,				nullptr,			offsetof( GlobalData, m_cameraHeight ) },
+#endif
 	{ "MaxCameraHeight",						INI::parseReal,				nullptr,			offsetof( GlobalData, m_maxCameraHeight ) },
 	{ "MinCameraHeight",						INI::parseReal,				nullptr,			offsetof( GlobalData, m_minCameraHeight ) },
 	{ "TerrainHeightAtEdgeOfMap",					INI::parseReal,				nullptr,			offsetof( GlobalData, m_terrainHeightAtEdgeOfMap ) },
@@ -842,7 +844,9 @@ GlobalData::GlobalData()
 
 	m_cameraPitch = 0.0f;
 	m_cameraYaw = 0.0f;
+#if PRESERVE_RETAIL_SCRIPTED_CAMERA
 	m_cameraHeight = 0.0f;
+#endif
 	m_minCameraHeight = 100.0f;
 	m_maxCameraHeight = 300.0f;
 	m_terrainHeightAtEdgeOfMap = 0.0f;