/*
===========================================================================

Radiant terrain authoring

This is editor source data only.  The heightfields draw live in Radiant and are
saved beside the map as .terrain files; later bake/export code can consume the
same data without coupling sculpting to runtime geometry.

===========================================================================
*/

#include "precompiled.h"
#pragma hdrstop

#include "qe3.h"
#include "CamWnd.h"
#include "Terrain.h"
#include "../../models/TerrainModel.h"

#include <math.h>

#define TERRAIN_DEFAULT_RADIUS		256.0f
#define TERRAIN_DEFAULT_STRENGTH	96.0f
#define TERRAIN_DEFAULT_PAINT_STRENGTH	2.0f
#define TERRAIN_MAX_BRUSH_RADIUS	4096.0f
#define TERRAIN_MIN_BRUSH_RADIUS	8.0f
#define TERRAIN_MAX_BRUSH_STRENGTH	4096.0f
#define TERRAIN_MIN_BRUSH_STRENGTH	1.0f
#define TERRAIN_MAX_PAINT_STRENGTH	20.0f
#define TERRAIN_MIN_PAINT_STRENGTH	0.05f

typedef enum terrainToolMode_s {
	TERRAIN_TOOL_SCULPT,
	TERRAIN_TOOL_PAINT
} terrainToolMode_t;

typedef idTerrainPatch terrainObject_t;

typedef struct terrainStrokeChange_s {
	int		sample;
	bool	heightChanged;
	float	oldHeight;
	float	newHeight;
	bool	weightChanged;
	idVec4	oldWeight;
	idVec4	newWeight;
} terrainStrokeChange_t;

typedef struct terrainUndo_s {
	int		terrainIndex;
	idList<terrainStrokeChange_t> changes;
} terrainUndo_t;

typedef struct terrainStroke_s {
	bool	active;
	int		terrainIndex;
	terrainToolMode_t toolMode;
	int		lastTime;
	idList<terrainStrokeChange_t> changes;
} terrainStroke_t;

static idTerrainModel				s_terrainModel;
#define s_terrains					s_terrainModel.Terrains()
static idList<terrainUndo_t *>		s_undoStack;
static idList<terrainUndo_t *>		s_redoStack;
static terrainStroke_t				s_stroke;
static bool							s_editMode = false;
static bool							s_cursorValid = false;
static int							s_cursorTerrainIndex = -1;
static idVec3						s_cursorHit;
static idVec3						s_cursorNormal;
static terrainToolMode_t			s_toolMode = TERRAIN_TOOL_SCULPT;
static int							s_paintLayer = 1;
static float						s_brushRadius = TERRAIN_DEFAULT_RADIUS;
static float						s_brushStrength = TERRAIN_DEFAULT_STRENGTH;
static float						s_paintStrength = TERRAIN_DEFAULT_PAINT_STRENGTH;

static void Terrain_ClearUndoStacks(void) {
	s_undoStack.DeleteContents(true);
	s_redoStack.DeleteContents(true);
	s_stroke.active = false;
	s_stroke.terrainIndex = -1;
	s_stroke.toolMode = TERRAIN_TOOL_SCULPT;
	s_stroke.lastTime = 0;
	s_stroke.changes.Clear();
}

static idStr Terrain_FileName(const char *mapFileName) {
	idStr fileName = mapFileName && mapFileName[0] ? mapFileName : currentmap;
	return idTerrainModel::FileNameForMap(fileName.c_str());
}

static int Terrain_SampleIndex(const terrainObject_t *terrain, int x, int y) {
	return terrain->SampleIndex(x, y);
}

static int Terrain_PaintIndex(const terrainObject_t *terrain, int x, int y) {
	return terrain->PaintIndex(x, y);
}

static void Terrain_MarkPaintTextureDirty(terrainObject_t *terrain) {
	if (terrain) {
		terrain->MarkPaintTextureDirty();
	}
}

static void Terrain_ClearPaintTextureDirtyRect(terrainObject_t *terrain) {
	if (terrain) {
		terrain->ClearPaintTextureDirtyRect();
	}
}

static void Terrain_MarkPaintTextureDirtyRect(terrainObject_t *terrain, int minX, int minY, int maxX, int maxY) {
	if (terrain) {
		terrain->MarkPaintTextureDirtyRect(minX, minY, maxX, maxY);
	}
}

static float Terrain_SampleHeight(const terrainObject_t *terrain, int x, int y) {
	return terrain->SampleHeight(x, y);
}

static idVec4 Terrain_BaseLayerWeight(void) {
	return idTerrainPatch::BaseLayerWeight();
}

static idVec4 Terrain_NormalizeLayerWeight(const idVec4 &weight) {
	return idTerrainPatch::NormalizeLayerWeight(weight);
}

static float Terrain_WorldWidth(const terrainObject_t *terrain) {
	return terrain->WorldWidth();
}

static float Terrain_WorldHeight(const terrainObject_t *terrain) {
	return terrain->WorldHeight();
}

static float Terrain_BilinearHeight(const terrainObject_t *terrain, float u, float v) {
	return terrain->BilinearHeight(u, v);
}

static idVec3 Terrain_VertexUV(const terrainObject_t *terrain, float u, float v) {
	return terrain->VertexUV(u, v);
}

static idVec3 Terrain_Vertex(const terrainObject_t *terrain, int x, int y) {
	return terrain->Vertex(x, y);
}

static idVec3 Terrain_VertexNormal(const terrainObject_t *terrain, int x, int y) {
	return terrain->VertexNormal(x, y);
}

static void Terrain_UpdateBounds(terrainObject_t *terrain) {
	if (terrain) {
		terrain->UpdateBounds();
	}
}

static const char *Terrain_DefaultMaterial(void) {
	const char *selected = g_qeglobals.d_texturewin.texdef.name;
	if (selected && selected[0] && selected[0] != '(') {
		return selected;
	}
	return "textures/common/caulk";
}

static void Terrain_EnsureLayerData(terrainObject_t *terrain) {
	if (terrain) {
		terrain->EnsureLayerData(Terrain_DefaultMaterial());
	}
}

static idVec4 Terrain_SamplePaintWeight(const terrainObject_t *terrain, int x, int y) {
	return terrain->SamplePaintWeight(x, y);
}

static terrainObject_t *Terrain_NewDefault(const idVec3 &center) {
	return s_terrainModel.AllocDefaultTerrain(center, Terrain_DefaultMaterial(), (float)g_qeglobals.d_gridsize);
}

static void Terrain_FreeGLResources(terrainObject_t *terrain) {
	if (!terrain || terrain->paintTexture == 0) {
		return;
	}
	GLuint texture = terrain->paintTexture;
	glDeleteTextures(1, &texture);
	terrain->paintTexture = 0;
	Terrain_MarkPaintTextureDirty(terrain);
}

void Terrain_Clear(void) {
	for (int i = 0; i < s_terrains.Num(); i++) {
		Terrain_FreeGLResources(s_terrains[i]);
	}
	s_terrainModel.Clear();
	Terrain_ClearUndoStacks();
	s_cursorValid = false;
	s_cursorTerrainIndex = -1;
}

int Terrain_NumTerrains(void) {
	return s_terrains.Num();
}

bool Terrain_IsEditMode(void) {
	return s_editMode;
}

void Terrain_SetEditMode(bool enabled) {
	if (s_editMode == enabled) {
		return;
	}
	s_editMode = enabled;
	s_cursorValid = false;
	Sys_Status(enabled ? "Terrain edit mode enabled\n" : "Terrain edit mode disabled\n", 0);
	Sys_UpdateWindows(W_ALL);
}

void Terrain_ToggleEditMode(void) {
	Terrain_SetEditMode(!s_editMode);
}

void Terrain_CreateDefaultAtCamera(CCamWnd *cam) {
	idVec3 center;
	if (cam) {
		center = cam->Camera().origin;
	} else {
		center.Zero();
	}
	center.z = 0.0f;
	terrainObject_t *terrain = Terrain_NewDefault(center);
	s_terrains.Append(terrain);
	Terrain_SetEditMode(true);
	mapModified = 1;
	Sys_Status(va("Created terrain %s (%ix%i)\n", terrain->name.c_str(), terrain->width, terrain->height), 0);
	Sys_UpdateWindows(W_ALL);
}

static bool Terrain_RayTriangle(const idVec3 &origin, const idVec3 &dir, const idVec3 &v0, const idVec3 &v1, const idVec3 &v2, float &dist, idVec3 &normal) {
	const float epsilon = 0.0001f;
	idVec3 edge1 = v1 - v0;
	idVec3 edge2 = v2 - v0;
	idVec3 pvec = dir.Cross(edge2);
	float det = edge1 * pvec;
	if (fabs(det) < epsilon) {
		return false;
	}

	float invDet = 1.0f / det;
	idVec3 tvec = origin - v0;
	float u = (tvec * pvec) * invDet;
	if (u < 0.0f || u > 1.0f) {
		return false;
	}

	idVec3 qvec = tvec.Cross(edge1);
	float v = (dir * qvec) * invDet;
	if (v < 0.0f || u + v > 1.0f) {
		return false;
	}

	dist = (edge2 * qvec) * invDet;
	if (dist <= epsilon) {
		return false;
	}

	normal = edge1.Cross(edge2);
	if (normal.LengthSqr() > epsilon) {
		normal.Normalize();
		if ((normal * dir) > 0.0f) {
			normal *= -1.0f;
		}
	}
	else {
		normal.Set(0.0f, 0.0f, 1.0f);
	}
	return true;
}

static bool Terrain_RayBounds(const terrainObject_t *terrain, const idVec3 &origin, const idVec3 &dir) {
	float tMin = 0.0f;
	float tMax = HUGE_DISTANCE;
	for (int axis = 0; axis < 3; axis++) {
		const float min = terrain->bounds[0][axis] - s_brushRadius;
		const float max = terrain->bounds[1][axis] + s_brushRadius;
		if (fabs(dir[axis]) < 0.00001f) {
			if (origin[axis] < min || origin[axis] > max) {
				return false;
			}
			continue;
		}
		float invD = 1.0f / dir[axis];
		float t0 = (min - origin[axis]) * invD;
		float t1 = (max - origin[axis]) * invD;
		if (t0 > t1) {
			float tmp = t0;
			t0 = t1;
			t1 = tmp;
		}
		if (t0 > tMin) {
			tMin = t0;
		}
		if (t1 < tMax) {
			tMax = t1;
		}
		if (tMax < tMin) {
			return false;
		}
	}
	return true;
}

static bool Terrain_RayTrace(const idVec3 &origin, const idVec3 &dir, int &terrainIndex, idVec3 &hit, idVec3 &normal) {
	float bestDist = HUGE_DISTANCE;
	int bestTerrain = -1;
	idVec3 bestNormal;

	for (int i = 0; i < s_terrains.Num(); i++) {
		terrainObject_t *terrain = s_terrains[i];
		if (!terrain || terrain->width < 2 || terrain->height < 2) {
			continue;
		}
		if (!Terrain_RayBounds(terrain, origin, dir)) {
			continue;
		}

		for (int y = 0; y < terrain->height - 1; y++) {
			for (int x = 0; x < terrain->width - 1; x++) {
				idVec3 v00 = Terrain_Vertex(terrain, x, y);
				idVec3 v10 = Terrain_Vertex(terrain, x + 1, y);
				idVec3 v01 = Terrain_Vertex(terrain, x, y + 1);
				idVec3 v11 = Terrain_Vertex(terrain, x + 1, y + 1);
				float dist;
				idVec3 triNormal;
				if (Terrain_RayTriangle(origin, dir, v00, v10, v11, dist, triNormal) && dist < bestDist) {
					bestDist = dist;
					bestTerrain = i;
					bestNormal = triNormal;
				}
				if (Terrain_RayTriangle(origin, dir, v00, v11, v01, dist, triNormal) && dist < bestDist) {
					bestDist = dist;
					bestTerrain = i;
					bestNormal = triNormal;
				}
			}
		}
	}

	if (bestTerrain < 0) {
		return false;
	}

	terrainIndex = bestTerrain;
	hit = origin + dir * bestDist;
	normal = bestNormal;
	return true;
}

static void Terrain_BuildCameraRay(CCamWnd *cam, const CPoint &point, idVec3 &origin, idVec3 &dir) {
	CRect rect;
	cam->GetClientRect(rect);
	camera_t &camera = cam->Camera();
	const int x = point.x;
	const int y = rect.bottom - 1 - point.y;

	float r = 0.0f;
	float u = 0.0f;
	if (camera.width > 0) {
		r = (float)(x - camera.width / 2) / (camera.width / 2);
		u = (float)(y - camera.height / 2) / (camera.width / 2);
	}

	origin = camera.origin;
	for (int i = 0; i < 3; i++) {
		dir[i] = camera.vpn[i] + camera.vright[i] * r + camera.vup[i] * u;
	}
	dir.Normalize();
}

static bool Terrain_UpdateCursor(CCamWnd *cam, const CPoint &point) {
	if (!cam || !Terrain_IsEditMode()) {
		s_cursorValid = false;
		s_cursorTerrainIndex = -1;
		return false;
	}

	idVec3 origin;
	idVec3 dir;
	Terrain_BuildCameraRay(cam, point, origin, dir);

	int terrainIndex;
	idVec3 hit;
	idVec3 normal;
	if (!Terrain_RayTrace(origin, dir, terrainIndex, hit, normal)) {
		s_cursorValid = false;
		s_cursorTerrainIndex = -1;
		return false;
	}

	s_cursorValid = true;
	s_cursorTerrainIndex = terrainIndex;
	s_cursorHit = hit;
	s_cursorNormal = normal;
	return true;
}

static int Terrain_FindStrokeChange(int sample) {
	for (int i = 0; i < s_stroke.changes.Num(); i++) {
		if (s_stroke.changes[i].sample == sample) {
			return i;
		}
	}
	return -1;
}

static void Terrain_RecordStrokeChange(int sample, float oldHeight, float newHeight) {
	int existing = Terrain_FindStrokeChange(sample);
	if (existing >= 0) {
		s_stroke.changes[existing].heightChanged = true;
		s_stroke.changes[existing].newHeight = newHeight;
		return;
	}

	terrainStrokeChange_t change;
	change.sample = sample;
	change.heightChanged = true;
	change.oldHeight = oldHeight;
	change.newHeight = newHeight;
	change.weightChanged = false;
	change.oldWeight = Terrain_BaseLayerWeight();
	change.newWeight = Terrain_BaseLayerWeight();
	s_stroke.changes.Append(change);
}

static void Terrain_RecordPaintChange(int sample, const idVec4 &oldWeight, const idVec4 &newWeight) {
	int existing = Terrain_FindStrokeChange(sample);
	if (existing >= 0) {
		s_stroke.changes[existing].weightChanged = true;
		s_stroke.changes[existing].newWeight = newWeight;
		return;
	}

	terrainStrokeChange_t change;
	change.sample = sample;
	change.heightChanged = false;
	change.oldHeight = 0.0f;
	change.newHeight = 0.0f;
	change.weightChanged = true;
	change.oldWeight = oldWeight;
	change.newWeight = newWeight;
	s_stroke.changes.Append(change);
}

static void Terrain_ApplyBrushAt(int terrainIndex, const idVec3 &hit, float seconds, bool lower) {
	if (terrainIndex < 0 || terrainIndex >= s_terrains.Num()) {
		return;
	}

	terrainObject_t *terrain = s_terrains[terrainIndex];
	if (!terrain) {
		return;
	}

	if (seconds <= 0.0f) {
		seconds = 0.025f;
	}
	else if (seconds > 0.1f) {
		seconds = 0.1f;
	}

	const float sign = lower ? -1.0f : 1.0f;
	const float amount = sign * s_brushStrength * seconds;
	const float radiusSqr = s_brushRadius * s_brushRadius;

	for (int y = 0; y < terrain->height; y++) {
		for (int x = 0; x < terrain->width; x++) {
			idVec3 v = Terrain_Vertex(terrain, x, y);
			idVec2 delta(v.x - hit.x, v.y - hit.y);
			float distSqr = delta.LengthSqr();
			if (distSqr > radiusSqr) {
				continue;
			}

			float dist = sqrt(distSqr);
			float t = 1.0f - idMath::ClampFloat(0.0f, 1.0f, dist / s_brushRadius);
			float falloff = t * t * (3.0f - 2.0f * t);
			int sample = Terrain_SampleIndex(terrain, x, y);
			float oldHeight = terrain->heights[sample];
			float newHeight = oldHeight + amount * falloff;
			if (newHeight == oldHeight) {
				continue;
			}
			terrain->SetHeight(x, y, newHeight);
			Terrain_RecordStrokeChange(sample, oldHeight, newHeight);
		}
	}

	Terrain_UpdateBounds(terrain);
	mapModified = 1;
}

static bool Terrain_WeightsDiffer(const idVec4 &a, const idVec4 &b) {
	return idMath::Fabs(a.x - b.x) > 0.0001f ||
		idMath::Fabs(a.y - b.y) > 0.0001f ||
		idMath::Fabs(a.z - b.z) > 0.0001f ||
		idMath::Fabs(a.w - b.w) > 0.0001f;
}

static void Terrain_EnsurePaintLayerMaterial(terrainObject_t *terrain, int layer) {
	if (!terrain || layer < 0 || layer >= TERRAIN_MAX_LAYERS) {
		return;
	}
	Terrain_EnsureLayerData(terrain);
	if (!terrain->layerMaterials[layer].IsEmpty()) {
		return;
	}

	terrain->layerMaterials[layer] = Terrain_DefaultMaterial();
	Texture_ForName(terrain->layerMaterials[layer].c_str());
}

static idVec4 Terrain_PaintLayerWeight(const idVec4 &oldWeight, int layer, float amount, bool erase) {
	idVec4 weight = Terrain_NormalizeLayerWeight(oldWeight);
	amount = idMath::ClampFloat(0.0f, 1.0f, amount);

	if (erase) {
		weight[layer] = idMath::ClampFloat(0.0f, 1.0f, weight[layer] - amount);
		return Terrain_NormalizeLayerWeight(weight);
	}

	for (int i = 0; i < TERRAIN_MAX_LAYERS; i++) {
		weight[i] *= (1.0f - amount);
	}
	weight[layer] += amount;
	return Terrain_NormalizeLayerWeight(weight);
}

static void Terrain_ApplyPaintAt(int terrainIndex, const idVec3 &hit, float seconds, bool erase) {
	if (terrainIndex < 0 || terrainIndex >= s_terrains.Num()) {
		return;
	}

	terrainObject_t *terrain = s_terrains[terrainIndex];
	if (!terrain) {
		return;
	}

	if (seconds <= 0.0f) {
		seconds = 0.025f;
	}
	else if (seconds > 0.1f) {
		seconds = 0.1f;
	}

	Terrain_EnsureLayerData(terrain);
	Terrain_EnsurePaintLayerMaterial(terrain, s_paintLayer);

	const float amount = s_paintStrength * seconds;
	const float radiusSqr = s_brushRadius * s_brushRadius;
	const float worldWidth = Terrain_WorldWidth(terrain);
	const float worldHeight = Terrain_WorldHeight(terrain);
	if (worldWidth <= 0.0f || worldHeight <= 0.0f) {
		return;
	}

	const float invWorldWidth = 1.0f / worldWidth;
	const float invWorldHeight = 1.0f / worldHeight;
	const float minU = idMath::ClampFloat(0.0f, 1.0f, (hit.x - s_brushRadius - terrain->origin.x) * invWorldWidth);
	const float maxU = idMath::ClampFloat(0.0f, 1.0f, (hit.x + s_brushRadius - terrain->origin.x) * invWorldWidth);
	const float minV = idMath::ClampFloat(0.0f, 1.0f, (hit.y - s_brushRadius - terrain->origin.y) * invWorldHeight);
	const float maxV = idMath::ClampFloat(0.0f, 1.0f, (hit.y + s_brushRadius - terrain->origin.y) * invWorldHeight);
	const int minX = idMath::ClampInt(0, terrain->paintWidth - 1, (int)floorf(minU * (float)(terrain->paintWidth - 1)));
	const int maxX = idMath::ClampInt(0, terrain->paintWidth - 1, (int)ceilf(maxU * (float)(terrain->paintWidth - 1)));
	const int minY = idMath::ClampInt(0, terrain->paintHeight - 1, (int)floorf(minV * (float)(terrain->paintHeight - 1)));
	const int maxY = idMath::ClampInt(0, terrain->paintHeight - 1, (int)ceilf(maxV * (float)(terrain->paintHeight - 1)));
	bool changed = false;

	for (int y = minY; y <= maxY; y++) {
		const float v = (float)y / (float)(terrain->paintHeight - 1);
		const float worldY = terrain->origin.y + worldHeight * v;
		for (int x = minX; x <= maxX; x++) {
			const float u = (float)x / (float)(terrain->paintWidth - 1);
			const float worldX = terrain->origin.x + worldWidth * u;
			idVec2 delta(worldX - hit.x, worldY - hit.y);
			float distSqr = delta.LengthSqr();
			if (distSqr > radiusSqr) {
				continue;
			}

			float dist = sqrt(distSqr);
			float t = 1.0f - idMath::ClampFloat(0.0f, 1.0f, dist / s_brushRadius);
			float falloff = t * t * (3.0f - 2.0f * t);
			int sample = Terrain_PaintIndex(terrain, x, y);
			idVec4 oldWeight = terrain->paintWeights[sample];
			idVec4 newWeight = Terrain_PaintLayerWeight(oldWeight, s_paintLayer, amount * falloff, erase);
			if (!Terrain_WeightsDiffer(oldWeight, newWeight)) {
				continue;
			}
			terrain->SetPaintWeight(x, y, newWeight);
			Terrain_RecordPaintChange(sample, oldWeight, newWeight);
			changed = true;
		}
	}

	if (changed) {
		Terrain_MarkPaintTextureDirtyRect(terrain, minX, minY, maxX, maxY);
		mapModified = 1;
	}
}

static void Terrain_BeginStroke(int terrainIndex) {
	s_stroke.active = true;
	s_stroke.terrainIndex = terrainIndex;
	s_stroke.toolMode = s_toolMode;
	s_stroke.lastTime = Sys_Milliseconds();
	s_stroke.changes.Clear();
}

static void Terrain_EndStroke(bool keep) {
	if (!s_stroke.active) {
		return;
	}

	if (keep && s_stroke.changes.Num() > 0) {
		terrainUndo_t *undo = new terrainUndo_t;
		undo->terrainIndex = s_stroke.terrainIndex;
		undo->changes = s_stroke.changes;
		s_undoStack.Append(undo);
		s_redoStack.DeleteContents(true);
	}

	s_stroke.active = false;
	s_stroke.terrainIndex = -1;
	s_stroke.lastTime = 0;
	s_stroke.changes.Clear();
}

static bool Terrain_StrokeApplyAtCursor(CCamWnd *cam, const CPoint &point, UINT flags, bool forceFirstSample) {
	if (!s_stroke.active) {
		return false;
	}

	if (!Terrain_UpdateCursor(cam, point)) {
		return true;
	}

	int terrainIndex;
	idVec3 origin;
	idVec3 dir;
	idVec3 hit;
	idVec3 normal;
	Terrain_BuildCameraRay(cam, point, origin, dir);
	if (!Terrain_RayTrace(origin, dir, terrainIndex, hit, normal)) {
		return true;
	}
	if (terrainIndex != s_stroke.terrainIndex) {
		return true;
	}

	int now = Sys_Milliseconds();
	float seconds = forceFirstSample ? 0.05f : (now - s_stroke.lastTime) * 0.001f;
	s_stroke.lastTime = now;

	const bool lower = (flags & MK_SHIFT) != 0 || (GetAsyncKeyState(VK_SHIFT) & 0x8000) != 0;
	if (s_stroke.toolMode == TERRAIN_TOOL_PAINT) {
		Terrain_ApplyPaintAt(terrainIndex, hit, seconds, lower);
	}
	else {
		Terrain_ApplyBrushAt(terrainIndex, hit, seconds, lower);
	}
	Sys_UpdateWindows(W_ALL);
	return true;
}

bool Terrain_LButtonDown(CCamWnd *cam, const CPoint &point, UINT flags) {
	if (!Terrain_IsEditMode() || !cam) {
		return false;
	}
	if (s_terrains.Num() <= 0) {
		return false;
	}

	if (!Terrain_UpdateCursor(cam, point)) {
		return false;
	}

	idVec3 origin;
	idVec3 dir;
	idVec3 hit;
	idVec3 normal;
	int terrainIndex;
	Terrain_BuildCameraRay(cam, point, origin, dir);
	if (!Terrain_RayTrace(origin, dir, terrainIndex, hit, normal)) {
		return false;
	}

	cam->SetFocus();
	cam->SetCapture();
	Terrain_BeginStroke(terrainIndex);
	Terrain_StrokeApplyAtCursor(cam, point, flags, true);
	return true;
}

bool Terrain_LButtonUp(CCamWnd *cam, const CPoint &point, UINT flags) {
	if (!s_stroke.active) {
		return false;
	}
	Terrain_StrokeApplyAtCursor(cam, point, flags, false);
	Terrain_EndStroke(true);
	if (cam && ::GetCapture() == cam->GetSafeHwnd()) {
		::ReleaseCapture();
	}
	Sys_UpdateWindows(W_ALL);
	return true;
}

void Terrain_CancelStroke(void) {
	if (!s_stroke.active) {
		return;
	}
	Terrain_EndStroke(false);
	s_cursorValid = false;
	Sys_UpdateWindows(W_CAMERA);
}

bool Terrain_MouseMove(CCamWnd *cam, const CPoint &point, UINT flags) {
	if (s_stroke.active) {
		return Terrain_StrokeApplyAtCursor(cam, point, flags, false);
	}
	if (!Terrain_IsEditMode()) {
		return false;
	}
	bool hadCursor = s_cursorValid;
	bool hasCursor = Terrain_UpdateCursor(cam, point);
	if (hadCursor != hasCursor || hasCursor) {
		if (cam) {
			cam->InvalidateRect(NULL, FALSE);
		}
	}
	return false;
}

static const char *Terrain_ToolName(void) {
	return s_toolMode == TERRAIN_TOOL_PAINT ? "paint" : "sculpt";
}

static void Terrain_SetToolMode(terrainToolMode_t mode) {
	if (s_toolMode == mode) {
		return;
	}
	s_toolMode = mode;
	Sys_Status(va("Terrain %s mode\n", Terrain_ToolName()), 0);
	Sys_UpdateWindows(W_CAMERA);
}

static void Terrain_ToggleToolMode(void) {
	Terrain_SetToolMode(s_toolMode == TERRAIN_TOOL_PAINT ? TERRAIN_TOOL_SCULPT : TERRAIN_TOOL_PAINT);
}

bool Terrain_IsPaintMode(void) {
	return s_toolMode == TERRAIN_TOOL_PAINT;
}

void Terrain_SetPaintMode(bool enabled) {
	Terrain_SetToolMode(enabled ? TERRAIN_TOOL_PAINT : TERRAIN_TOOL_SCULPT);
}

int Terrain_GetPaintLayer(void) {
	return s_paintLayer;
}

static terrainObject_t *Terrain_TargetForLayerDialog(void) {
	if (s_cursorTerrainIndex >= 0 && s_cursorTerrainIndex < s_terrains.Num()) {
		return s_terrains[s_cursorTerrainIndex];
	}
	if (s_terrains.Num() > 0) {
		return s_terrains[0];
	}
	return NULL;
}

void Terrain_SelectPaintLayer(int layer) {
	s_paintLayer = idMath::ClampInt(0, TERRAIN_MAX_LAYERS - 1, layer);
	Sys_Status(va("Terrain paint layer %i\n", s_paintLayer + 1), 0);
	Sys_UpdateWindows(W_CAMERA);
}

static idStr Terrain_CleanMaterialName(const char *materialName) {
	idStr cleaned = materialName ? materialName : "";
	cleaned.StripTrailingWhitespace();
	cleaned.Strip(' ');
	cleaned.Strip('\t');
	cleaned.StripQuotes();
	return cleaned;
}

static bool Terrain_SetLayerMaterials(terrainObject_t *terrain, const idStr layerMaterials[TERRAIN_MAX_LAYERS]) {
	if (!terrain) {
		return false;
	}

	Terrain_EnsureLayerData(terrain);
	idStr oldLayerMaterials[TERRAIN_MAX_LAYERS];
	for (int layer = 0; layer < TERRAIN_MAX_LAYERS; layer++) {
		oldLayerMaterials[layer] = terrain->layerMaterials[layer];
	}

	const bool changed = terrain->SetLayerMaterials(layerMaterials, Terrain_DefaultMaterial());
	for (int layer = 0; layer < TERRAIN_MAX_LAYERS; layer++) {
		if (!terrain->layerMaterials[layer].IsEmpty() && oldLayerMaterials[layer].Icmp(terrain->layerMaterials[layer].c_str()) != 0) {
			Texture_ForName(terrain->layerMaterials[layer].c_str());
		}
	}

	if (changed) {
		mapModified = 1;
		Sys_UpdateWindows(W_ALL);
	}

	return changed;
}

enum {
	TERRAIN_LAYER_DLG_EDIT_BASE = 7000,
	TERRAIN_LAYER_DLG_USE_SELECTED_BASE = 7010,
	TERRAIN_LAYER_DLG_CLEAR_BASE = 7020
};

typedef struct terrainLayerDialogState_s {
	terrainObject_t *terrain;
	HWND owner;
	HWND dialog;
	HWND edits[TERRAIN_MAX_LAYERS];
	bool accepted;
	bool changed;
} terrainLayerDialogState_t;

static void Terrain_SetDialogFont(HWND hWnd, HFONT font) {
	if (hWnd && font) {
		SendMessage(hWnd, WM_SETFONT, (WPARAM)font, TRUE);
	}
}

static HWND Terrain_CreateDialogControl(terrainLayerDialogState_t *state, const char *className, const char *text, DWORD style, int id, int x, int y, int w, int h, HFONT font) {
	HWND control = CreateWindowExA(
		(strcmp(className, "EDIT") == 0) ? WS_EX_CLIENTEDGE : 0,
		className,
		text,
		WS_CHILD | WS_VISIBLE | style,
		x,
		y,
		w,
		h,
		state->dialog,
		(HMENU)(INT_PTR)id,
		GetModuleHandle(NULL),
		NULL);
	Terrain_SetDialogFont(control, font);
	return control;
}

static void TerrainLayerDialog_FillEdits(terrainLayerDialogState_t *state) {
	if (!state || !state->terrain) {
		return;
	}
	Terrain_EnsureLayerData(state->terrain);
	for (int layer = 0; layer < TERRAIN_MAX_LAYERS; layer++) {
		SetWindowTextA(state->edits[layer], state->terrain->layerMaterials[layer].c_str());
	}
}

static void TerrainLayerDialog_Apply(terrainLayerDialogState_t *state) {
	if (!state || !state->terrain) {
		return;
	}

	idStr layerMaterials[TERRAIN_MAX_LAYERS];
	for (int layer = 0; layer < TERRAIN_MAX_LAYERS; layer++) {
		char text[MAX_OSPATH];
		text[0] = '\0';
		GetWindowTextA(state->edits[layer], text, sizeof(text));
		layerMaterials[layer] = Terrain_CleanMaterialName(text);
	}

	state->changed = Terrain_SetLayerMaterials(state->terrain, layerMaterials);
	state->accepted = true;
	DestroyWindow(state->dialog);
}

static LRESULT CALLBACK TerrainLayerDialogProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
	terrainLayerDialogState_t *state = (terrainLayerDialogState_t *)GetWindowLongPtr(hWnd, GWLP_USERDATA);

	switch (uMsg) {
	case WM_NCCREATE:
		state = (terrainLayerDialogState_t *)((CREATESTRUCT *)lParam)->lpCreateParams;
		SetWindowLongPtr(hWnd, GWLP_USERDATA, (LONG_PTR)state);
		return TRUE;

	case WM_CREATE:
	{
		state->dialog = hWnd;
		HFONT font = (HFONT)GetStockObject(DEFAULT_GUI_FONT);
		Terrain_SetDialogFont(hWnd, font);

		Terrain_CreateDialogControl(state, "STATIC", state->terrain ? state->terrain->name.c_str() : "", SS_LEFT, -1, 14, 12, 360, 18, font);
		for (int layer = 0; layer < TERRAIN_MAX_LAYERS; layer++) {
			const int y = 42 + layer * 30;
			Terrain_CreateDialogControl(state, "STATIC", va("Layer %i", layer + 1), SS_LEFT, -1, 14, y + 4, 58, 18, font);
			state->edits[layer] = Terrain_CreateDialogControl(state, "EDIT", "", ES_AUTOHSCROLL, TERRAIN_LAYER_DLG_EDIT_BASE + layer, 74, y, 288, 22, font);
			Terrain_CreateDialogControl(state, "BUTTON", "Use selected", BS_PUSHBUTTON, TERRAIN_LAYER_DLG_USE_SELECTED_BASE + layer, 370, y, 88, 22, font);
			HWND clearButton = Terrain_CreateDialogControl(state, "BUTTON", "Clear", BS_PUSHBUTTON, TERRAIN_LAYER_DLG_CLEAR_BASE + layer, 466, y, 56, 22, font);
			if (layer == 0) {
				EnableWindow(clearButton, FALSE);
			}
		}

		Terrain_CreateDialogControl(state, "BUTTON", "OK", BS_DEFPUSHBUTTON, IDOK, 342, 174, 82, 24, font);
		Terrain_CreateDialogControl(state, "BUTTON", "Cancel", BS_PUSHBUTTON, IDCANCEL, 436, 174, 82, 24, font);
		TerrainLayerDialog_FillEdits(state);
		SetFocus(state->edits[0]);
		return 0;
	}

	case WM_COMMAND:
	{
		const int command = LOWORD(wParam);
		if (command == IDOK) {
			TerrainLayerDialog_Apply(state);
			return 0;
		}
		if (command == IDCANCEL) {
			DestroyWindow(hWnd);
			return 0;
		}
		if (command >= TERRAIN_LAYER_DLG_USE_SELECTED_BASE && command < TERRAIN_LAYER_DLG_USE_SELECTED_BASE + TERRAIN_MAX_LAYERS) {
			int layer = command - TERRAIN_LAYER_DLG_USE_SELECTED_BASE;
			SetWindowTextA(state->edits[layer], Terrain_DefaultMaterial());
			return 0;
		}
		if (command >= TERRAIN_LAYER_DLG_CLEAR_BASE && command < TERRAIN_LAYER_DLG_CLEAR_BASE + TERRAIN_MAX_LAYERS) {
			int layer = command - TERRAIN_LAYER_DLG_CLEAR_BASE;
			if (layer > 0) {
				SetWindowTextA(state->edits[layer], "");
			}
			return 0;
		}
		break;
	}

	case WM_CLOSE:
		DestroyWindow(hWnd);
		return 0;

	case WM_DESTROY:
		if (state && state->owner && IsWindow(state->owner)) {
			EnableWindow(state->owner, TRUE);
			SetActiveWindow(state->owner);
		}
		return 0;
	}

	return DefWindowProc(hWnd, uMsg, wParam, lParam);
}

static ATOM TerrainLayerDialog_RegisterClass(void) {
	static ATOM atom = 0;
	if (atom) {
		return atom;
	}

	WNDCLASSA wc;
	memset(&wc, 0, sizeof(wc));
	wc.style = CS_DBLCLKS;
	wc.lpfnWndProc = TerrainLayerDialogProc;
	wc.hInstance = GetModuleHandle(NULL);
	wc.hCursor = LoadCursor(NULL, IDC_ARROW);
	wc.hbrBackground = (HBRUSH)(COLOR_BTNFACE + 1);
	wc.lpszClassName = "RadiantTerrainLayerDialog";
	atom = RegisterClassA(&wc);
	return atom;
}

bool Terrain_ShowLayersDialog(CCamWnd *cam) {
	terrainObject_t *terrain = Terrain_TargetForLayerDialog();
	if (!terrain) {
		Sys_Status("Create a terrain before editing terrain layers\n", 0);
		return false;
	}

	Terrain_EnsureLayerData(terrain);
	if (!TerrainLayerDialog_RegisterClass()) {
		common->Warning("Terrain_ShowLayersDialog: failed to register dialog class");
		return false;
	}

	HWND owner = cam && cam->GetSafeHwnd() ? cam->GetSafeHwnd() : (g_pParentWnd ? g_pParentWnd->GetSafeHwnd() : NULL);
	terrainLayerDialogState_t state;
	memset(&state, 0, sizeof(state));
	state.terrain = terrain;
	state.owner = owner;

	RECT ownerRect = { 0, 0, 0, 0 };
	if (owner && IsWindow(owner)) {
		GetWindowRect(owner, &ownerRect);
	}
	else {
		ownerRect.left = 200;
		ownerRect.top = 150;
		ownerRect.right = 800;
		ownerRect.bottom = 550;
	}

	const int width = 540;
	const int height = 236;
	const int x = ownerRect.left + ((ownerRect.right - ownerRect.left) - width) / 2;
	const int y = ownerRect.top + ((ownerRect.bottom - ownerRect.top) - height) / 2;

	if (owner) {
		EnableWindow(owner, FALSE);
	}

	HWND dialog = CreateWindowExA(
		WS_EX_DLGMODALFRAME | WS_EX_WINDOWEDGE,
		"RadiantTerrainLayerDialog",
		"Terrain Layers",
		WS_POPUP | WS_CAPTION | WS_SYSMENU,
		x,
		y,
		width,
		height,
		owner,
		NULL,
		GetModuleHandle(NULL),
		&state);
	if (!dialog) {
		if (owner) {
			EnableWindow(owner, TRUE);
		}
		common->Warning("Terrain_ShowLayersDialog: failed to create dialog");
		return false;
	}

	ShowWindow(dialog, SW_SHOW);
	UpdateWindow(dialog);

	MSG msg;
	while (IsWindow(dialog) && GetMessage(&msg, NULL, 0, 0) > 0) {
		if (!IsDialogMessage(dialog, &msg)) {
			TranslateMessage(&msg);
			DispatchMessage(&msg);
		}
	}

	if (owner && IsWindow(owner)) {
		EnableWindow(owner, TRUE);
		SetActiveWindow(owner);
	}

	if (state.accepted && state.changed) {
		Sys_Status("Terrain layers updated\n", 0);
	}
	return state.changed;
}

void Terrain_AdjustBrushRadius(float scale) {
	s_brushRadius *= scale;
	s_brushRadius = idMath::ClampFloat(TERRAIN_MIN_BRUSH_RADIUS, TERRAIN_MAX_BRUSH_RADIUS, s_brushRadius);
	Sys_Status(va("Terrain radius %.1f\n", s_brushRadius), 0);
	Sys_UpdateWindows(W_CAMERA);
}

void Terrain_AdjustBrushStrength(float scale) {
	if (s_toolMode == TERRAIN_TOOL_PAINT) {
		s_paintStrength *= scale;
		s_paintStrength = idMath::ClampFloat(TERRAIN_MIN_PAINT_STRENGTH, TERRAIN_MAX_PAINT_STRENGTH, s_paintStrength);
		Sys_Status(va("Terrain paint flow %.2f\n", s_paintStrength), 0);
		Sys_UpdateWindows(W_CAMERA);
		return;
	}

	s_brushStrength *= scale;
	s_brushStrength = idMath::ClampFloat(TERRAIN_MIN_BRUSH_STRENGTH, TERRAIN_MAX_BRUSH_STRENGTH, s_brushStrength);
	Sys_Status(va("Terrain strength %.1f\n", s_brushStrength), 0);
	Sys_UpdateWindows(W_CAMERA);
}

bool Terrain_HandleKeyDown(CCamWnd *cam, UINT key) {
	const bool ctrl = (GetAsyncKeyState(VK_CONTROL) & 0x8000) != 0;
	const bool shift = (GetAsyncKeyState(VK_SHIFT) & 0x8000) != 0;
	const bool alt = (GetAsyncKeyState(VK_MENU) & 0x8000) != 0;

	if (!alt && key == 'T') {
		if (ctrl || shift || s_terrains.Num() <= 0) {
			Terrain_CreateDefaultAtCamera(cam);
		}
		else {
			Terrain_ToggleEditMode();
		}
		return true;
	}

	if (!Terrain_IsEditMode()) {
		return false;
	}

	if (!alt && key == 'P') {
		Terrain_ToggleToolMode();
		return true;
	}
	if (!alt && key >= '1' && key <= '4') {
		const int layer = key - '1';
		Terrain_SelectPaintLayer(layer);
		return true;
	}
	if (!alt && key >= VK_NUMPAD1 && key <= VK_NUMPAD4) {
		const int layer = key - VK_NUMPAD1;
		Terrain_SelectPaintLayer(layer);
		return true;
	}
	if (key == VK_OEM_4) {
		Terrain_AdjustBrushRadius(0.8f);
		return true;
	}
	if (key == VK_OEM_6) {
		Terrain_AdjustBrushRadius(1.25f);
		return true;
	}
	if (key == VK_SUBTRACT || key == VK_OEM_MINUS) {
		Terrain_AdjustBrushStrength(0.8f);
		return true;
	}
	if (key == VK_ADD || key == VK_OEM_PLUS) {
		Terrain_AdjustBrushStrength(1.25f);
		return true;
	}

	return false;
}

bool Terrain_HandleChar(CCamWnd *cam, UINT key) {
	if (!Terrain_IsEditMode()) {
		return false;
	}
	switch (key) {
	case '[':
	case '{':
		Terrain_AdjustBrushRadius(0.8f);
		return true;
	case ']':
	case '}':
		Terrain_AdjustBrushRadius(1.25f);
		return true;
	case '-':
	case '_':
		Terrain_AdjustBrushStrength(0.8f);
		return true;
	case '+':
	case '=':
		Terrain_AdjustBrushStrength(1.25f);
		return true;
	}
	return false;
}

static idImage *Terrain_LayerEditorImage(const char *materialName) {
	if (!materialName || !materialName[0]) {
		return NULL;
	}

	const idMaterial *material = Texture_ForName(materialName);
	if (!material || material->TestMaterialFlag(MF_DEFAULTED)) {
		return NULL;
	}

	return material->GetEditorImage();
}

static idImage *Terrain_LayerNormalImage(const char *materialName) {
	idImage *flatNormal = globalImages->flatNormalMap ? globalImages->flatNormalMap : globalImages->whiteImage;
	if (!materialName || !materialName[0]) {
		return flatNormal;
	}

	const idMaterial *material = Texture_ForName(materialName);
	if (!material || material->TestMaterialFlag(MF_DEFAULTED)) {
		return flatNormal;
	}

	const shaderStage_t *bumpStage = material->GetBumpStage();
	if (!bumpStage || !bumpStage->texture.image) {
		return flatNormal;
	}

	return bumpStage->texture.image;
}

static byte Terrain_WeightToByte(float value) {
	return (byte)idMath::ClampInt(0, 255, (int)floorf(idMath::ClampFloat(0.0f, 1.0f, value) * 255.0f + 0.5f));
}

static void Terrain_FillPaintPixels(terrainObject_t *terrain, int minX, int minY, int uploadWidth, int uploadHeight, idList<byte> &pixels) {
	pixels.SetNum(uploadWidth * uploadHeight * 4);
	for (int y = 0; y < uploadHeight; y++) {
		for (int x = 0; x < uploadWidth; x++) {
			const int sample = Terrain_PaintIndex(terrain, minX + x, minY + y);
			const int pixel = (y * uploadWidth + x) * 4;
			const idVec4 weights = Terrain_NormalizeLayerWeight(terrain->paintWeights[sample]);
			pixels[pixel + 0] = Terrain_WeightToByte(weights.x);
			pixels[pixel + 1] = Terrain_WeightToByte(weights.y);
			pixels[pixel + 2] = Terrain_WeightToByte(weights.z);
			pixels[pixel + 3] = Terrain_WeightToByte(weights.w);
		}
	}
}

static GLuint Terrain_UpdatePaintTexture(terrainObject_t *terrain) {
	Terrain_EnsureLayerData(terrain);
	bool newTexture = false;
	if (terrain->paintTexture == 0) {
		glGenTextures(1, &terrain->paintTexture);
		Terrain_MarkPaintTextureDirty(terrain);
		newTexture = true;
	}

	if (!terrain->paintTextureDirty) {
		return terrain->paintTexture;
	}

	const int minX = idMath::ClampInt(0, terrain->paintWidth - 1, terrain->paintDirtyMinX);
	const int minY = idMath::ClampInt(0, terrain->paintHeight - 1, terrain->paintDirtyMinY);
	const int maxX = idMath::ClampInt(0, terrain->paintWidth - 1, terrain->paintDirtyMaxX);
	const int maxY = idMath::ClampInt(0, terrain->paintHeight - 1, terrain->paintDirtyMaxY);
	const bool validRect = maxX >= minX && maxY >= minY;
	const bool fullUpload = newTexture || !validRect ||
		(minX == 0 && minY == 0 && maxX == terrain->paintWidth - 1 && maxY == terrain->paintHeight - 1);
	const int uploadX = fullUpload ? 0 : minX;
	const int uploadY = fullUpload ? 0 : minY;
	const int uploadWidth = fullUpload ? terrain->paintWidth : (maxX - minX + 1);
	const int uploadHeight = fullUpload ? terrain->paintHeight : (maxY - minY + 1);

	glBindTexture(GL_TEXTURE_2D, terrain->paintTexture);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

	idList<byte> pixels;
	Terrain_FillPaintPixels(terrain, uploadX, uploadY, uploadWidth, uploadHeight, pixels);
	if (fullUpload) {
		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, terrain->paintWidth, terrain->paintHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels.Ptr());
	}
	else {
		glTexSubImage2D(GL_TEXTURE_2D, 0, uploadX, uploadY, uploadWidth, uploadHeight, GL_RGBA, GL_UNSIGNED_BYTE, pixels.Ptr());
	}

	Terrain_ClearPaintTextureDirtyRect(terrain);
	return terrain->paintTexture;
}

static void Terrain_BindLayerTextures(terrainObject_t *terrain) {
	Terrain_EnsureLayerData(terrain);

	idImage *baseImage = Terrain_LayerEditorImage(terrain->layerMaterials[0].c_str());
	if (!baseImage) {
		baseImage = globalImages->whiteImage;
	}

	for (int layer = 0; layer < TERRAIN_MAX_LAYERS; layer++) {
		idImage *image = Terrain_LayerEditorImage(terrain->layerMaterials[layer].c_str());
		if (!image) {
			image = baseImage;
		}

		image->Bind();
		glTerrainLayerTextureQD3D12(layer, image->texnum);

		idImage *normalImage = Terrain_LayerNormalImage(terrain->layerMaterials[layer].c_str());
		if (!normalImage) {
			normalImage = globalImages->flatNormalMap ? globalImages->flatNormalMap : globalImages->whiteImage;
		}
		normalImage->Bind();
		glTerrainLayerNormalTextureQD3D12(layer, normalImage->texnum);
	}
	glTerrainWeightTextureQD3D12(Terrain_UpdatePaintTexture(terrain));
}

static void Terrain_ClearLayerTextureBindings(void) {
	glTerrainBlendEnableQD3D12(GL_FALSE);
	glTerrainBlendOpacityQD3D12(1.0f);
	glTerrainWeightTextureQD3D12(0);
	for (int layer = 0; layer < TERRAIN_MAX_LAYERS; layer++) {
		glTerrainLayerTextureQD3D12(layer, 0);
		glTerrainLayerNormalTextureQD3D12(layer, 0);
	}
}

static void Terrain_SubmitTexturedVertex(terrainObject_t *terrain, int x, int y) {
	idVec3 v = Terrain_Vertex(terrain, x, y);
	idVec3 normal = Terrain_VertexNormal(terrain, x, y);
	const float u = (float)x / (float)(terrain->width - 1);
	const float vCoord = (float)y / (float)(terrain->height - 1);
	const float layerS = Terrain_WorldWidth(terrain) * u / 256.0f;
	const float layerT = Terrain_WorldHeight(terrain) * vCoord / 256.0f;
	const int paintX = idMath::ClampInt(0, terrain->paintWidth - 1, (int)floorf(u * (float)(terrain->paintWidth - 1) + 0.5f));
	const int paintY = idMath::ClampInt(0, terrain->paintHeight - 1, (int)floorf(vCoord * (float)(terrain->paintHeight - 1) + 0.5f));
	const idVec4 weights = Terrain_NormalizeLayerWeight(Terrain_SamplePaintWeight(terrain, paintX, paintY));

	glColor4fv(weights.ToFloatPtr());
	glNormal3fv(normal.ToFloatPtr());
	glMultiTexCoord2fARB(GL_TEXTURE0_ARB, layerS, layerT);
	glMultiTexCoord2fARB(GL_TEXTURE1_ARB, u, vCoord);
	glVertex3fv(v.ToFloatPtr());
}

static idVec4 Terrain_PaintLayerColor(void) {
	static const idVec4 colors[TERRAIN_MAX_LAYERS] = {
		idVec4(0.95f, 0.80f, 0.10f, 1.0f),
		idVec4(0.10f, 0.75f, 1.0f, 1.0f),
		idVec4(0.15f, 0.95f, 0.35f, 1.0f),
		idVec4(0.95f, 0.25f, 0.85f, 1.0f)
	};
	return colors[idMath::ClampInt(0, TERRAIN_MAX_LAYERS - 1, s_paintLayer)];
}

static void Terrain_DrawObjectCam(terrainObject_t *terrain, bool selected) {
	if (!terrain || terrain->width < 2 || terrain->height < 2) {
		return;
	}

	Terrain_EnsureLayerData(terrain);

	glPushAttrib(GL_ALL_ATTRIB_BITS);
	glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_LEQUAL);
	glDepthMask(GL_TRUE);
	glDisable(GL_CULL_FACE);
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

	glEnable(GL_TEXTURE_2D);
	Terrain_BindLayerTextures(terrain);
	glTerrainBlendEnableQD3D12(GL_TRUE);
	glTerrainBlendOpacityQD3D12(selected ? 0.85f : 0.72f);

	glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
	for (int y = 0; y < terrain->height - 1; y++) {
		glBegin(GL_TRIANGLE_STRIP);
		for (int x = 0; x < terrain->width; x++) {
			Terrain_SubmitTexturedVertex(terrain, x, y);
			Terrain_SubmitTexturedVertex(terrain, x, y + 1);
		}
		glEnd();
	}
	Terrain_ClearLayerTextureBindings();

	glDisable(GL_TEXTURE_2D);
	globalImages->BindNull();
	glDisable(GL_BLEND);
	glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
	glLineWidth(selected ? 1.5f : 0.5f);
	glColor4f(selected ? 1.0f : 0.45f, selected ? 0.82f : 0.62f, selected ? 0.08f : 0.50f, 1.0f);
	glBegin(GL_LINES);
	for (int y = 0; y < terrain->height; y++) {
		for (int x = 0; x < terrain->width - 1; x++) {
			idVec3 a = Terrain_Vertex(terrain, x, y);
			idVec3 b = Terrain_Vertex(terrain, x + 1, y);
			glVertex3fv(a.ToFloatPtr());
			glVertex3fv(b.ToFloatPtr());
		}
	}
	for (int x = 0; x < terrain->width; x++) {
		for (int y = 0; y < terrain->height - 1; y++) {
			idVec3 a = Terrain_Vertex(terrain, x, y);
			idVec3 b = Terrain_Vertex(terrain, x, y + 1);
			glVertex3fv(a.ToFloatPtr());
			glVertex3fv(b.ToFloatPtr());
		}
	}
	glEnd();

	glDepthFunc(GL_LEQUAL);
	glDepthMask(GL_TRUE);
	glDisable(GL_BLEND);
	glEnable(GL_TEXTURE_2D);
	glPopAttrib();
}

static void Terrain_DrawBrushCursor(void) {
	if (!s_editMode || !s_cursorValid) {
		return;
	}

	glPushAttrib(GL_ALL_ATTRIB_BITS);
	glDisable(GL_TEXTURE_2D);
	glDisable(GL_DEPTH_TEST);
	glLineWidth(2.0f);
	idVec4 cursorColor = s_toolMode == TERRAIN_TOOL_PAINT ? Terrain_PaintLayerColor() : idVec4(0.08f, 0.75f, 1.0f, 1.0f);
	glColor4f(cursorColor.x, cursorColor.y, cursorColor.z, cursorColor.w);
	globalImages->BindNull();

	const int segments = 64;
	glBegin(GL_LINE_LOOP);
	for (int i = 0; i < segments; i++) {
		float a = (float)i * idMath::TWO_PI / (float)segments;
		idVec3 p;
		p.x = s_cursorHit.x + cos(a) * s_brushRadius;
		p.y = s_cursorHit.y + sin(a) * s_brushRadius;
		p.z = s_cursorHit.z + 2.0f;
		glVertex3fv(p.ToFloatPtr());
	}
	glEnd();

	glBegin(GL_LINES);
	idVec3 normalEnd = s_cursorHit + s_cursorNormal * idMath::ClampFloat(12.0f, 64.0f, s_brushRadius * 0.25f);
	glVertex3fv(s_cursorHit.ToFloatPtr());
	glVertex3fv(normalEnd.ToFloatPtr());
	glEnd();

	glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_LEQUAL);
	glDepthMask(GL_TRUE);
	glDisable(GL_BLEND);
	glEnable(GL_TEXTURE_2D);
	glPopAttrib();
}

void Terrain_DrawCam(CCamWnd *cam) {
	for (int i = 0; i < s_terrains.Num(); i++) {
		Terrain_DrawObjectCam(s_terrains[i], s_editMode);
	}
	Terrain_DrawBrushCursor();
}

void Terrain_DrawXY(int viewType) {
	glPushAttrib(GL_ALL_ATTRIB_BITS);
	glDisable(GL_TEXTURE_2D);
	glDisable(GL_BLEND);
	globalImages->BindNull();
	glLineWidth(s_editMode ? 1.0f : 0.5f);
	glColor3f(s_editMode ? 0.95f : 0.45f, s_editMode ? 0.72f : 0.56f, s_editMode ? 0.08f : 0.32f);

	for (int i = 0; i < s_terrains.Num(); i++) {
		terrainObject_t *terrain = s_terrains[i];
		if (!terrain || terrain->width < 2 || terrain->height < 2) {
			continue;
		}
		glBegin(GL_LINES);
		for (int y = 0; y < terrain->height; y++) {
			for (int x = 0; x < terrain->width - 1; x++) {
				idVec3 a = Terrain_Vertex(terrain, x, y);
				idVec3 b = Terrain_Vertex(terrain, x + 1, y);
				glVertex3fv(a.ToFloatPtr());
				glVertex3fv(b.ToFloatPtr());
			}
		}
		for (int x = 0; x < terrain->width; x++) {
			for (int y = 0; y < terrain->height - 1; y++) {
				idVec3 a = Terrain_Vertex(terrain, x, y);
				idVec3 b = Terrain_Vertex(terrain, x, y + 1);
				glVertex3fv(a.ToFloatPtr());
				glVertex3fv(b.ToFloatPtr());
			}
		}
		glEnd();
	}
	glPopAttrib();
}

bool Terrain_UndoAvailable(void) {
	return s_undoStack.Num() > 0;
}

bool Terrain_RedoAvailable(void) {
	return s_redoStack.Num() > 0;
}

static void Terrain_ApplyUndo(terrainUndo_t *undo, bool redo) {
	if (!undo || undo->terrainIndex < 0 || undo->terrainIndex >= s_terrains.Num()) {
		return;
	}
	terrainObject_t *terrain = s_terrains[undo->terrainIndex];
	if (!terrain) {
		return;
	}
	Terrain_EnsureLayerData(terrain);
	for (int i = 0; i < undo->changes.Num(); i++) {
		const terrainStrokeChange_t &change = undo->changes[i];
		if (change.heightChanged) {
			if (!terrain->SetHeightBySample(change.sample, redo ? change.newHeight : change.oldHeight)) {
				continue;
			}
		}
		if (change.weightChanged) {
			if (!terrain->SetPaintWeightBySample(change.sample, redo ? change.newWeight : change.oldWeight)) {
				continue;
			}
		}
	}
	Terrain_UpdateBounds(terrain);
	mapModified = 1;
	Sys_UpdateWindows(W_ALL);
}

bool Terrain_Undo(void) {
	if (!Terrain_UndoAvailable()) {
		return false;
	}
	terrainUndo_t *undo = s_undoStack[s_undoStack.Num() - 1];
	s_undoStack.RemoveIndex(s_undoStack.Num() - 1);
	Terrain_ApplyUndo(undo, false);
	s_redoStack.Append(undo);
	Sys_Status("Terrain undo\n", 0);
	return true;
}

bool Terrain_Redo(void) {
	if (!Terrain_RedoAvailable()) {
		return false;
	}
	terrainUndo_t *undo = s_redoStack[s_redoStack.Num() - 1];
	s_redoStack.RemoveIndex(s_redoStack.Num() - 1);
	Terrain_ApplyUndo(undo, true);
	s_undoStack.Append(undo);
	Sys_Status("Terrain redo\n", 0);
	return true;
}

void Terrain_Save(const char *mapFileName) {
	idStr terrainFile = Terrain_FileName(mapFileName);
	s_terrainModel.SaveFile(terrainFile.c_str());
}

static void Terrain_TouchLayerMaterials(terrainObject_t *terrain) {
	if (!terrain) {
		return;
	}
	Terrain_EnsureLayerData(terrain);
	for (int layer = 0; layer < TERRAIN_MAX_LAYERS; layer++) {
		if (!terrain->layerMaterials[layer].IsEmpty()) {
			Texture_ForName(terrain->layerMaterials[layer].c_str());
		}
	}
}

void Terrain_Load(const char *mapFileName) {
	Terrain_Clear();

	idStr terrainFile = Terrain_FileName(mapFileName);
	if (!s_terrainModel.LoadFile(terrainFile.c_str(), Terrain_DefaultMaterial())) {
		return;
	}

	for (int i = 0; i < s_terrains.Num(); i++) {
		terrainObject_t *terrain = s_terrains[i];
		if (!terrain) {
			continue;
		}
		terrain->paintTexture = 0;
		Terrain_MarkPaintTextureDirty(terrain);
		Terrain_TouchLayerMaterials(terrain);
	}

	Terrain_ClearUndoStacks();
	s_cursorValid = false;
	s_cursorTerrainIndex = -1;
}