/* This file is part of the Spring engine (GPL v2 or later), see LICENSE.html */

#include <cstdarg>
#include <cstring>

#include "TerrainBase.h"
#include "Terrain.h"
#include "TerrainVertexBuffer.h"

#include "System/TdfParser.h"

#include <deque>
#include <fstream>
#include <IL/il.h>
#include "TerrainTexture.h"
#include "TerrainNode.h"
#include "System/FileSystem/FileHandler.h"
#include "System/FileSystem/FileSystem.h"
#include "System/Log/ILog.h"
#include "System/StringUtil.h"
#include <assert.h>

// define this for big endian machines
//#define SWAP_SHORT

namespace terrain {

	Config::Config()
	{
		cacheTextures = false;
		useBumpMaps = false;
		terrainNormalMaps = false;
		detailMod = 2.0f;
		normalMapLevel = 2;
		cacheTextureSize = 128;
		useShadowMaps = false;
		anisotropicFiltering = 0;
		forceFallbackTexturing = false;
		maxLodLevel = 4;
		useStaticShadow = false;
	}


	void ILoadCallback::PrintMsg(const char* fmt, ...)
	{
		char buf[256];

		va_list l;
		va_start(l, fmt);
		VSNPRINTF(buf, sizeof(buf), fmt, l);
		va_end(l);

		Write(buf);
	}

//-----------------------------------------------------------------------
// Quad map - stores a 2D map of the quad nodes,
//            for quick access of nabours
//-----------------------------------------------------------------------

	void QuadMap::Alloc(int W)
	{
		w = W;
		map = new TQuad*[w*w];
	}

	void QuadMap::Fill(TQuad* q)
	{
		At(q->qmPos.x, q->qmPos.y) = q;

		if (!q->isLeaf()) {
			assert(highDetail);

			for (int a = 0; a < 4; a++)
				highDetail->Fill(q->children[a]);
		}
	}


//-----------------------------------------------------------------------
// Terrain Quadtree Node
//-----------------------------------------------------------------------

	TQuad::TQuad()
	{
		parent = 0;
		for (int a = 0; a < 4; a++)
			children[a] = 0;
		depth = width = 0;
		drawState = NoDraw;
		renderData = 0;
		textureSetup = 0;
		cacheTexture = 0;
		normalData = 0;
		maxLodValue = 0.0f;
	}

	TQuad::~TQuad()
	{
		if (!isLeaf()) {
			for (int a = 0; a < 4; a++)
				delete children[a];
		}

		// delete cached texture
		if (cacheTexture) {
			glDeleteTextures(1, &cacheTexture);
			cacheTexture = 0;
		}
	}

	void TQuad::Build(Heightmap* hm, int2 sqStart, int2 hmStart, int2 quadPos, int w, int d)
	{
		// create child nodes if necessary
		if (hm->highDetail) {
			for (int a = 0; a < 4; a++) {
				children[a] = new TQuad;
				children[a]->parent = this;

				int2 sqPos(sqStart.x   + (a & 1)*w/2, sqStart.y + (a & 2)*w/4); // square pos
				int2 hmPos(hmStart.x*2 + (a & 1)*QUAD_W, hmStart.y*2 + (a & 2)*QUAD_W/2); // heightmap pos
				int2 cqPos(quadPos.x*2 + (a & 1), quadPos.y*2 + (a & 2)/2);// child quad pos

				children[a]->Build(hm->highDetail, sqPos, hmPos, cqPos, w/2, d + 1);
			}
		}

		float minH, maxH;
		hm->FindMinMax(hmStart, int2(QUAD_W, QUAD_W), minH, maxH);

		start = Vector3(sqStart.x,   0.0f, sqStart.y)     * SquareSize;
		end = Vector3(sqStart.x + w, 0.0f, sqStart.y + w) * SquareSize;

		start.y = minH;
		end.y = maxH;

		hmPos = hmStart;
		qmPos = quadPos;
		sqPos = sqStart;
		depth = d;
		width = w;
	}

	int TQuad::GetVertexSize()
	{
		// compile-time assert
		typedef int vector_should_be_12_bytes [(sizeof(Vector3) == 12) ? 1 : -1];
		int vertexSize = 12;

		uint vda = textureSetup->vertexDataReq;
		if (vda & VRT_Normal)
			vertexSize += 12;
		if (vda & VRT_TangentSpaceMatrix)
			vertexSize += 12 * 3;
		return vertexSize;
	}

	void TQuad::Draw(IndexTable* indexTable, bool onlyPositions, int lodState)
	{
		uint vda = textureSetup->vertexDataReq;
		int vertexSize = GetVertexSize();

		// Bind the vertex buffer components
		Vector3* vbuf = static_cast<Vector3*>(renderData->vertexBuffer.Bind());
		glEnableClientState(GL_VERTEX_ARRAY);
		glVertexPointer(3, GL_FLOAT, vertexSize, vbuf ++);
		if (vda & VRT_Normal)
		{
			if (!onlyPositions) {
				glEnableClientState(GL_NORMAL_ARRAY);
				glNormalPointer(GL_FLOAT, vertexSize, vbuf);
			}
			vbuf ++;
		}
		if (vda & VRT_TangentSpaceMatrix)
		{
			if (!onlyPositions) {
				assert(textureSetup->currentShaderSetup);
				textureSetup->currentShaderSetup->BindTSM(vbuf, vertexSize);
			}
			vbuf += 3;
		}

		// Bind the index buffer and render
		IndexBuffer& ibuf = indexTable->buffers [lodState];
		glDrawElements(GL_TRIANGLES, indexTable->size [lodState], indexTable->IndexType(), ibuf.Bind());
		ibuf.Unbind();

		// Unbind the vertex buffer
		if (!onlyPositions) {
			if (vda&VRT_Normal) glDisableClientState(GL_NORMAL_ARRAY);
			if (vda&VRT_TangentSpaceMatrix) textureSetup->currentShaderSetup->UnbindTSM();
		}
		glDisableClientState(GL_VERTEX_ARRAY);
		renderData->vertexBuffer.Unbind();
	}

	bool TQuad::InFrustum(Frustum* f)
	{
		Vector3 boxSt = start, boxEnd = end;
		return f->IsBoxVisible(boxSt, boxEnd) != Frustum::Outside;
	}

	// Calculates the exact nearest point, not just one of the box'es vertices
	void NearestBoxPoint(const Vector3* min, const Vector3* max, const Vector3* pos, Vector3* out)
	{
//		Vector3 mid = (*max + *min) * 0.5f;
		if(pos->x < min->x) out->x = min->x;
		else if(pos->x > max->x) out->x = max->x;
		else out->x = pos->x;
		if(pos->y < min->y) out->y = min->y;
		else if(pos->y > max->y) out->y = max->y;
		else out->y = pos->y;
		if(pos->z < min->z) out->z = min->z;
		else if(pos->z > max->z) out->z = max->z;
		else out->z = pos->z;
	}

	float TQuad::CalcLod(const Vector3& campos)
	{
		Vector3 nearest;
		NearestBoxPoint(&start, &end, &campos, &nearest);

		float nodesize = end.x - start.x;
	//	float sloped = 0.01f * (1.0f + end.y - start.y);
		nearest -= campos;
		//return math::sqrtf(sloped) * nodesize / (nearest.length () + 0.1f);
		return nodesize / (nearest.Length() + 0.1f);
	}

	void TQuad::CollectNodes(std::vector<TQuad*>& quads)
	{
		if (!isLeaf()) {
			for (int a = 0; a < 4; a++)
				children[a]->CollectNodes(quads);
		}
		quads.push_back(this);
	}

	void TQuad::FreeCachedTexture()
	{
		if (cacheTexture) {
			glDeleteTextures(1,&cacheTexture);
			cacheTexture = 0;
		}
	}

	TQuad* TQuad::FindSmallestContainingQuad2D(const Vector3& pos, float range, int maxdepth)
	{
		if (depth < maxdepth)
		{
			for (int a = 0; a < 4; a++) {
				TQuad* r = children[a]->FindSmallestContainingQuad2D(pos,range,maxdepth);
				if (r) return r;
			}
		}
		if (start.x <= pos.x - range && end.x >= pos.x + range &&
			start.z <= pos.z - range && end.z >= pos.z + range)
			return this;
		return 0;
	}

//-----------------------------------------------------------------------
// Terrain Main class
//-----------------------------------------------------------------------

	Terrain::Terrain()
		: heightmap(NULL)
		, lowdetailhm(NULL)
		, quadtree(NULL)
		, activeRC(NULL)
		, curRC(NULL)
		, indexTable(NULL)
		, texturing(NULL)
		, shadowMap(0)
		, quadTreeDepth(0)
		, renderDataManager(NULL)
		, debugQuad(NULL)
		, nodeUpdateCount(0)
		, logUpdates(false)
	{
	}

	Terrain::~Terrain()
	{
		delete renderDataManager;
        delete texturing;
		while (heightmap) {
			Heightmap* tmpHm = heightmap;
			heightmap = heightmap->lowDetail;
			delete tmpHm;
		}
		for (size_t a = 0; a < qmaps.size(); a++) {
			delete qmaps[a];
		}
		qmaps.clear();
		delete quadtree;
		delete indexTable;
	}

	void Terrain::SetShadowMap(uint shadowTex)
	{
		shadowMap = shadowTex;
	}

	// used by ForceQueue to queue quads
	void Terrain::QueueLodFixQuad(TQuad* q)
	{
		if (q->drawState == TQuad::Queued)
			return;

		if (q->drawState == TQuad::NoDraw) {
			// make sure the parent is drawn
			assert (q->parent);
			QueueLodFixQuad (q->parent);

			// change the queued quad to a parent quad
			q->parent->drawState = TQuad::Parent;
			for (int a = 0; a < 4; a++) {
				TQuad* ch = q->parent->children [a];

				updatequads.push_back(ch);
				ch->drawState = TQuad::Queued;
				UpdateLodFix(ch);
			}
		}
	}

	void Terrain::ForceQueue(TQuad* q)
	{
		// See if the quad is culled against the view frustum
		TQuad* p = q->parent;
		while (p) {
			if (p->drawState == TQuad::Culled)
				return;
			if (p->drawState == TQuad::Queued)
				break;
			p = p->parent;
		}
		// Quad is not culled, so make sure it is drawn
		QueueLodFixQuad(q);
	}

	inline void Terrain::CheckNabourLod(TQuad* q, int xOfs, int yOfs)
	{
		QuadMap* qm = qmaps[q->depth];
		TQuad* nb = qm->At(q->qmPos.x+xOfs, q->qmPos.y+yOfs);

		// Check the state of the nabour parent (q is already the parent),
		if (nb->drawState == TQuad::NoDraw) {
			// a parent of the node is either culled or drawn itself
			ForceQueue(nb);
			return;
		}
	    // Parent: a child node of the nabour is drawn, which will take care of LOD gaps fixing
		// Queued: drawn itself, so the index buffer can fix gaps for that
		// Culled: no gap fixing required
	}

	// Check nabour parent nodes to see if they need to be drawn to fix LOD gaps of this node.
	void Terrain::UpdateLodFix(TQuad* q)
	{
		if (q->drawState == TQuad::Culled)
			return;

		if (q->drawState == TQuad::Parent) {
			for(int a = 0; a < 4; a++)
				UpdateLodFix(q->children [a]);
		}
		else if (q->parent) {
			// find the nabours, and make sure at least them or their parents are drawn
			TQuad* parent = q->parent;
			QuadMap* qm = qmaps[parent->depth];
			if (parent->qmPos.x>0) CheckNabourLod(parent, -1, 0);
			if (parent->qmPos.y>0) CheckNabourLod(parent, 0, -1);
			if (parent->qmPos.x<qm->w-1) CheckNabourLod(parent, 1, 0);
			if (parent->qmPos.y<qm->w-1) CheckNabourLod(parent, 0, 1);
		}
	}

	// Handle visibility with the frustum, and select LOD based on distance to camera and LOD setting
	void Terrain::QuadVisLod(TQuad* q)
	{
		if (q->InFrustum(&frustum)) {
			// Node is visible, now determine if this LOD is suitable, or that a higher LOD should be used.
			float lod = config.detailMod * q->CalcLod(curRC->cam->pos);
			if (q->depth < quadTreeDepth-config.maxLodLevel || (lod > 1.0f && !q->isLeaf())) {
				q->drawState = TQuad::Parent;
				for (int a = 0; a < 4; a++)
					QuadVisLod(q->children[a]);
			} else q->drawState = TQuad::Queued;
			updatequads.push_back(q);

			// update max lod value
			if (q->maxLodValue < lod)
				q->maxLodValue = lod;
		} else {
			q->drawState = TQuad::Culled;
			culled.push_back(q);
		}
	}

	static inline bool QuadSortFunc(const QuadRenderInfo& q1, const QuadRenderInfo& q2)
	{
		return q1.quad->textureSetup->sortkey < q2.quad->textureSetup->sortkey;
	}


	// update quad node drawing list
	void Terrain::Update()
	{
		nodeUpdateCount = 0;

		renderDataManager->ClearStat();

		// clear LOD values of previously used renderquads
		for (size_t a = 0; a < contexts.size(); a++)
		{
			RenderContext* rc = contexts[a];
			for (size_t n = 0; n < rc->quads.size();n++) {
				TQuad* q = rc->quads [n].quad;

				q->maxLodValue = 0.0f;
				if (q->renderData)
					q->renderData->used = true;
			}
		}

		for (size_t ctx = 0; ctx < contexts.size(); ctx++)
		{
			RenderContext* rc = curRC = contexts[ctx];

			// Update the frustum based on the camera, to cull away TQuad nodes
			//Camera* camera = rc->cam;
		//	frustum.CalcCameraPlanes(&camera->GetPos(), &camera->right, &camera->up, &camera->front, camera->fov, camera->aspect);
			//assert(camera->GetPos().x == 0.0f || frustum.IsPointVisible(camera->GetPos() + camera->front * 20)==Frustum::Inside);

			// determine the new set of quads to draw
			QuadVisLod(quadtree);

			// go through nabours to make sure there is a maximum of one LOD difference between nabours
			UpdateLodFix(quadtree);

			if (debugQuad)
				ForceQueue(debugQuad);

			// update lod state and copy the rendering list to the render context...
			rc->quads.clear();
			for (size_t a = 0; a < updatequads.size(); a++)
			{
				if (updatequads[a]->drawState == TQuad::Queued)
				{
					TQuad* q = updatequads[a];
					// calculate lod state
					QuadMap* qm = qmaps[q->depth];
					int ls = 0;
					if (q->qmPos.x>0 && qm->At(q->qmPos.x-1,q->qmPos.y)->drawState == TQuad::NoDraw) ls |= left_bit;
					if (q->qmPos.y>0 && qm->At(q->qmPos.x,q->qmPos.y-1)->drawState == TQuad::NoDraw) ls |= up_bit;
					if (q->qmPos.x<qm->w-1 && qm->At(q->qmPos.x+1,q->qmPos.y)->drawState == TQuad::NoDraw) ls |= right_bit;
					if (q->qmPos.y<qm->w-1 && qm->At(q->qmPos.x,q->qmPos.y+1)->drawState == TQuad::NoDraw) ls |= down_bit;

					rc->quads.push_back(QuadRenderInfo());
					rc->quads.back().quad = q;
					rc->quads.back().lodState = ls;
					if (q->renderData) q->renderData->used = true;
				}
			}
			// sort rendering quads based on sorting key
			sort(rc->quads.begin(), rc->quads.end(), QuadSortFunc);

			// the active set of quads is determined, so their draw-states can be reset for the next context
			for (size_t a = 0; a < culled.size(); a++)
				culled[a]->drawState = TQuad::NoDraw;
			culled.clear();

			// clear the list of queued quads
			for (size_t a = 0; a < updatequads.size(); a++)
				updatequads[a]->drawState = TQuad::NoDraw;
			updatequads.clear();
		}

		renderDataManager->FreeUnused();

		for (size_t ctx = 0; ctx < contexts.size(); ctx++)
		{
			RenderContext* rc = curRC = contexts[ctx];

			// allocate required vertex buffers
			for (size_t a = 0; a < rc->quads.size(); a++)
			{
				TQuad* q = rc->quads[a].quad;

				if (!q->renderData) {
					renderDataManager->InitializeNode(q);

					if (config.terrainNormalMaps && rc->needsNormalMap)
						renderDataManager->InitializeNodeNormalMap(q, config.normalMapLevel);

					nodeUpdateCount ++;
				}
			}
		}

		if (logUpdates) {
			if (nodeUpdateCount) {
				LOG_L(L_DEBUG,
						"NodeUpdates: %d, NormalDataAllocs:%d, RenderDataAllocs:%d",
						nodeUpdateCount,
						renderDataManager->normalDataAllocates,
						renderDataManager->renderDataAllocates);
			}
		}
		curRC = 0;
	}

	void Terrain::DrawSimple()
	{
		glEnable(GL_CULL_FACE);

		for (size_t a = 0; a < activeRC->quads.size(); a++)
		{
			QuadRenderInfo* q = &activeRC->quads[a];
			q->quad->Draw(indexTable, true, q->lodState);
		}
	}

	void Terrain::DrawOverlayTexture(uint tex)
	{
		glEnable(GL_TEXTURE_2D);
		glBindTexture(GL_TEXTURE_2D, tex);
		glTexEnvi(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE, GL_MODULATE);
        SetTexGen(1.0f / (heightmap->w * SquareSize));

		DrawSimple();

		glDisable(GL_TEXTURE_GEN_S);
		glDisable(GL_TEXTURE_GEN_T);
		glDisable(GL_TEXTURE_2D);
	}

	void DrawNormals(TQuad* q, const Heightmap* hm)
	{
		glBegin(GL_LINES);
		for (int y = q->hmPos.y; y < q->hmPos.y + QUAD_W; y++)
			for (int x = q->hmPos.x; x < q->hmPos.x + QUAD_W; x++)
			{
				Vector3 origin(x * hm->squareSize, hm->atSynced(x, y), y * hm->squareSize);

				Vector3 tangent, binormal;
				CalculateTangents(hm, x, y, tangent, binormal);

				Vector3 normal = binormal.cross(tangent);
				normal.ANormalize();
				binormal.ANormalize();
				tangent.ANormalize();

				glColor3f(1, 1, 0);
				glVertex3fv(&origin[0]);
				glVertex3fv(&(origin + normal * 7)[0]);
				glColor3f(1, 0, 0);
				glVertex3fv(&origin[0]);
				glVertex3fv(&(origin + binormal * 7)[0]);
				glColor3f(0, 0, 1);
				glVertex3fv(&origin[0]);
				glVertex3fv(&(origin + tangent * 7)[0]);
			}
		glEnd();
		glColor3f(1, 1, 1);

	}

	void Terrain::Draw()
	{
		const float diffuse[] = { 1.0f, 1.0f, 1.0f, 1.0f };
		glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, diffuse);

		glEnable(GL_CULL_FACE);
		glColor3f(1.0f,1.0f,1.0f);

		if (config.cacheTextures)
		{
			// draw all terrain nodes using their cached textures
			glEnable(GL_TEXTURE_GEN_S);
			glEnable(GL_TEXTURE_GEN_T);
			glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
			glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);

			glEnable(GL_TEXTURE_2D);
			glDisable(GL_LIGHTING);

			for (size_t a = 0; a < activeRC->quads.size(); a++)
			{
				TQuad* q = activeRC->quads[a].quad;

				// set quad texture
				glBindTexture(GL_TEXTURE_2D, q->cacheTexture);

				// set texture gen
				float ht = (q->end.x-q->start.x) / ( 2 * config.cacheTextureSize );

				float v[4] = {0.0f, 0.0f, 0.0f, 0.0f};
				v[0] = 1.0f / (q->end.x - q->start.x + ht * 2);
				v[3] = -v[0] * (q->start.x - ht);
				glTexGenfv(GL_S, GL_OBJECT_PLANE, v);
				v[0] = 0.0f;
				v[2] = 1.0f / (q->end.z - q->start.z + ht * 2);
				v[3] = -v[2] * (q->start.z - ht);
				glTexGenfv(GL_T, GL_OBJECT_PLANE, v);

				// draw
				q->Draw(indexTable, false, activeRC->quads[a].lodState);
			}

			glDisable(GL_TEXTURE_2D);
			glDisable(GL_TEXTURE_GEN_S);
			glDisable(GL_TEXTURE_GEN_T);
		}
		else  // no texture caching, so use the texturing system directly
		{
			const int numPasses = texturing->NumPasses();

			glEnable(GL_DEPTH_TEST);

			texturing->BeginTexturing();

			for (int pass = 0; pass < numPasses; pass++) {
				texturing->BeginPass(pass);

				for (size_t a = 0; a < activeRC->quads.size(); a++) {
					TQuad* q = activeRC->quads[a].quad;

					// Setup node texturing
					const bool skipNodes = !texturing->SetupNode(q, pass);

					assert(q->renderData);

					if (!skipNodes) {
						// Draw the node
						q->Draw(indexTable, false, activeRC->quads[a].lodState);
					}
				}

				texturing->EndPass();
			}

			glDisable(GL_BLEND);
			glDepthMask(GL_TRUE);

			texturing->EndTexturing();
		}

		if (debugQuad)
			DrawNormals(debugQuad, lowdetailhm->GetLevel(debugQuad->depth));
	}

	void Terrain::CalcRenderStats(RenderStats& stats, RenderContext* ctx)
	{
		if (!ctx)
			ctx = activeRC;

		stats.cacheTextureSize = 0;
		stats.renderDataSize = 0;
		stats.tris = 0;

		for (size_t a = 0; a < ctx->quads.size(); a++) {
			TQuad* q = ctx->quads[a].quad;
			if (q->cacheTexture)
				stats.cacheTextureSize += config.cacheTextureSize * config.cacheTextureSize * 3;
			stats.renderDataSize += q->renderData->GetDataSize();
			stats.tris += MAX_INDICES/3;
		}
		stats.passes = texturing->NumPasses();
	}

#ifndef TERRAINRENDERERLIB_EXPORTS
	void Terrain::DebugPrint(IFontRenderer* fr)
	{
		if (fr != NULL) {
			const float s = 16.0f;

			if (debugQuad != NULL) {
				fr->printf(0, 30, s, "Selected quad: (%d,%d) on depth %d. Lod=%3.3f",
						debugQuad->qmPos.x, debugQuad->qmPos.y,
						debugQuad->depth,
						config.detailMod * debugQuad->CalcLod(activeRC->cam->pos));
			}

			RenderStats stats;
			CalcRenderStats(stats);

			fr->printf(0, 46, s, "Rendered nodes: %d, tris: %d, VBufSize: %d(kb), TotalRenderData(kb): %d, DetailMod: %g, CacheTextureMemory: %d",
					activeRC->quads.size(), stats.tris,
					VertexBuffer::TotalSize() / 1024,
					stats.renderDataSize / 1024, config.detailMod,
					stats.cacheTextureSize);
			fr->printf(0, 60, s, "NodeUpdateCount: %d, RenderDataAlloc: %d, #RenderData: %d",
					nodeUpdateCount, renderDataManager->normalDataAllocates,
					renderDataManager->QuadRenderDataCount());

			texturing->DebugPrint(fr);
		}
	}
#endif

	TQuad* FindQuad(TQuad* q, const Vector3& cpos)
	{
		if (cpos.x >= q->start.x && cpos.z >= q->start.z &&
			cpos.x < q->end.x && cpos.z < q->end.z)
		{
			if (q->isLeaf()) return q;

			for (int a = 0; a < 4; a++)  {
				TQuad* r = FindQuad(q->children[a], cpos);
				if (r) return r;
			}
		}
		return 0;
	}

	void Terrain::RenderNodeFlat(int x,int y,int depth)
	{
		RenderNode(qmaps[depth]->At(x,y));
	}

	void Terrain::RenderNode(TQuad* q)
	{
		// setup projection matrix, so the quad is exactly mapped onto the viewport
		glMatrixMode(GL_PROJECTION);
		glPushMatrix();
		glLoadIdentity();
		glOrtho(q->start.x, q->end.x, q->start.z, q->end.z, -10000.0f, 100000.0f);
		glColor3f(1.f,1.f,1.f);

		if (!q->renderData)
			renderDataManager->InitializeNode(q);

		texturing->BeginTexturing();
		// render to the framebuffer
		for (size_t p = 0; p < q->textureSetup->renderSetup[0]->passes.size(); p++)
		{
			texturing->BeginPass(p);
			if (texturing->SetupNode(q, p))
			{
				glBegin(GL_QUADS);
				glVertex3f(q->start.x, 0.0f, q->start.z);
				glVertex3f(q->end.x, 0.0f, q->start.z);
				glVertex3f(q->end.x, 0.0f, q->end.z);
				glVertex3f(q->start.x, 0.0f, q->end.z);
				glEnd();
			}
			texturing->EndPass();
		}
		texturing->EndTexturing();
		glMatrixMode(GL_PROJECTION);
		glPopMatrix();
	}

	void Terrain::CacheTextures()
	{
		if (!config.cacheTextures)
			return;

		glPushAttrib(GL_VIEWPORT_BIT | GL_DEPTH_BUFFER_BIT);
		glViewport(0, 0, config.cacheTextureSize, config.cacheTextureSize);

		glMatrixMode(GL_MODELVIEW);
		glPushMatrix();
		glLoadIdentity();

		float m[16];
		std::fill(m,m+16,0.0f);
		m[0] = m[6] = m[9] = m[15] = 1.0f;
		glLoadMatrixf(m);

		glDepthMask(GL_FALSE);
		glDisable(GL_DEPTH_TEST);
		glDisable(GL_CULL_FACE);

		glDisable(GL_LIGHTING);

		// Make sure every node that might be drawn, has a cached texture
		for (size_t ctx = 0; ctx < contexts.size(); ctx++)
		{
			RenderContext* rc = contexts[ctx];
			if (!rc->needsTexturing)
				continue;

			for (size_t a = 0; a < rc->quads.size(); a++)
			{
				TQuad* q = rc->quads[a].quad;

				if (q->cacheTexture)
					continue;

				RenderNode(q);

				// copy it to the texture
				glGenTextures(1, &q->cacheTexture);
				glBindTexture(GL_TEXTURE_2D, q->cacheTexture);
				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
				if (config.anisotropicFiltering > 0.0f)
					glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, config.anisotropicFiltering);
				glCopyTexImage2D(GL_TEXTURE_2D, 0,GL_RGB, 0,0, config.cacheTextureSize, config.cacheTextureSize, 0);
			}
		}

		glMatrixMode(GL_MODELVIEW);
		glPopMatrix();

		// restore viewport and depth buffer states
		glPopAttrib();
	}

	void Terrain::DebugEvent(const std::string& event)
	{
		if (event == "t_detail_inc")
			config.detailMod *= 1.2f;
		if (event == "t_detail_dec")
			config.detailMod /= 1.2f;
		if (event == "t_debugquad") {
			if (debugQuad)
				debugQuad = 0;
			else
				debugQuad = FindQuad(quadtree, activeRC->cam->pos);
			return;
		}
//		if (key == 'l')
//			logUpdates=!logUpdates;
		texturing->DebugEvent(event);
	}

	void Terrain::Load(const TdfParser& tdf, LightingInfo* li, ILoadCallback* cb)
	{
		// validate configuration
		if (config.cacheTextures)
			config.useBumpMaps = false;

		if (config.anisotropicFiltering != 0.0f)
			config.anisotropicFiltering = std::min(config.anisotropicFiltering, globalRendering->maxTexAnisoLvl);

		if (cb)
			cb->PrintMsg("initializing heightmap renderer...");

		// create a set of low resolution heightmaps
		int w = heightmap->w - 1;
		Heightmap* prev = heightmap;
		quadTreeDepth = 0;

		while (w > QUAD_W) {
			prev = prev->CreateLowDetailHM();
			quadTreeDepth++;
			w /= 2;
		}
		lowdetailhm = prev;
		assert((1 << quadTreeDepth) * (lowdetailhm->w - 1) == heightmap->w - 1);

		// set heightmap squareSize for all lod's
		heightmap->squareSize = SquareSize;

		for (Heightmap *lod = heightmap->lowDetail; lod; lod = lod->lowDetail)
			lod->squareSize = lod->highDetail->squareSize * 2.0f;

		// build a quadtree and a vertex buffer for each quad tree
		// prev is now the lowest detail heightmap, and will be used for the root quad tree node
		quadtree = new TQuad;
		quadtree->Build(lowdetailhm, int2(), int2(), int2(), heightmap->w-1, 0);

		// create a quad map for each LOD level
		Heightmap* cur = prev;
		QuadMap* qm = 0;

		while (cur) {
			if (qm) {
				qm->highDetail = new QuadMap;
				qm->highDetail->lowDetail = qm;
				qm = qm->highDetail;
			} else {
				qm = new QuadMap;
			}
			qm->Alloc((cur->w-1)/QUAD_W);
			qmaps.push_back(qm);
			cur = cur->highDetail;
		}

		// fill the quad maps (qmaps.front() is now the lowest detail quadmap)
		qmaps.front()->Fill(quadtree);

		// generate heightmap normals
		if (cb)
			cb->PrintMsg("  generating terrain normals for shading...");

		for (Heightmap *lod = heightmap; lod; lod = lod->lowDetail)
			lod->GenerateNormals();

		if (cb)
			cb->PrintMsg("initializing texturing system...");

		// load textures
		texturing = new TerrainTexture;
		texturing->Load(&tdf, heightmap, quadtree, qmaps, &config, cb, li);

		renderDataManager = new RenderDataManager(lowdetailhm, qmaps.front());

		// calculate index table
		indexTable = new IndexTable;
		LOG("Index buffer data size: %d", VertexBuffer::TotalSize());
	}

	void Terrain::LoadHeightMap(const TdfParser& parser, ILoadCallback* cb)
	{
		std::string heightMapName;
		parser.GetDef(heightMapName, std::string(), "MAP\\TERRAIN\\Heightmap");

		if (heightMapName.empty()) {
			throw content_error("No heightmap given");
		}

		std::string extension = FileSystem::GetExtension(heightMapName);

		if (extension == "raw") {
			heightmap = LoadHeightmapFromRAW(heightMapName, cb);
		} else {
			heightmap = LoadHeightmapFromImage(heightMapName, cb);
		}

		if (heightmap->dataSynced.empty()) {
			throw content_error("Failed to load heightmap " + heightMapName);
		}

		LOG("heightmap size: %dx%d", GetHeightmapWidth(), GetHeightmapHeight());

		const float hmScale = atof(parser.SGetValueDef("1000", "MAP\\TERRAIN\\HeightScale").c_str());
		const float hmOffset = atof(parser.SGetValueDef("0", "MAP\\TERRAIN\\HeightOffset").c_str());

		// apply scaling and offset to the heightmap ASAP
		for (int y = 0; y < heightmap->w * heightmap->h; y++) {
			heightmap->dataSynced[y] = heightmap->dataSynced[y] * hmScale + hmOffset;
			heightmap->dataUnsynced[y] = heightmap->dataSynced[y];
		}

		if ((GetHeightmapWidth() - 1) != atoi(parser.SGetValueDef("","MAP\\GameAreaW").c_str()) ||
			(GetHeightmapHeight() - 1) != atoi(parser.SGetValueDef("","MAP\\GameAreaH").c_str())) {
			char hmdims[32];
			SNPRINTF(hmdims, 32, "%dx%d", GetHeightmapWidth(), GetHeightmapHeight());
			throw content_error("Map size (" + std::string(hmdims) + ") should be equal to GameAreaW and GameAreaH");
		}
	}

	void Terrain::ReloadShaders()
	{
		texturing->ReloadShaders(quadtree, &config);
	}


	void FindRAWProps(int len, int& width, int& bytespp, ILoadCallback* cb)
	{
		// test for 16-bit
		int w = 3;
		while (w*w*2 < len)
			w = (w-1)*2+1;

		if (w*w*2 != len) {
			w = 3; // test for 8-bit
			while (w*w < len)
				w = (w-1)*2+1;

			if (w*w != len) {
				cb->PrintMsg("Incorrect raw file size: %d, last comparing size: %d", len, w*w*2);
				return;
			} else bytespp = 1;
		} else bytespp = 2;

		width = w;
	}

	Heightmap* Terrain::LoadHeightmapFromRAW(const std::string& file, ILoadCallback* cb)
	{
		CFileHandler fh(file);
		if (!fh.FileExists()) {
			cb->PrintMsg("Failed to load %s", file.c_str());
			return 0;
		}

		int len = fh.FileSize();
		int w = -1, bits;

		FindRAWProps(len, w, bits, cb);
		bits *= 8;

		if (w < 0)
			return 0;

		Heightmap* hm = new Heightmap;
		hm->Alloc(w, w);

		if (bits == 16) {
			std::vector<ushort> tmp(w * w);
			fh.Read(&tmp[0], len);

			for (int y = 0; y < w * w; y++) {
				hm->dataSynced[y] = float(tmp[y]) / float((1 << bits) - 1);
				hm->dataUnsynced[y] = hm->dataSynced[y];
			}
#ifdef SWAP_SHORT
			char* p = (char*)hm->data;
			for (int x = 0; x < len; x += 2, p += 2)
				std::swap(p[0], p[1]);
#endif
		} else {
			std::vector<uchar> buf(len);
			fh.Read(&buf[0], len);

			uchar* p = &buf[0];

			for (w = w * w - 1; w >= 0; w--) {
				hm->dataSynced[w] = *(p++) / float((1 << bits) - 1);
				hm->dataUnsynced[w] = hm->dataSynced[w];
			}
		}

		return hm;
	}

	Heightmap* Terrain::LoadHeightmapFromImage(const std::string& heightmapFile, ILoadCallback* cb)
	{
		const char* hmfile = heightmapFile.c_str();
		CFileHandler fh(heightmapFile);
		if (!fh.FileExists())
			throw content_error(heightmapFile + " does not exist");

		ILuint ilheightmap;
		ilGenImages(1, &ilheightmap);
		ilBindImage(ilheightmap);

		assert(fh.FileSize() >= 0);
		std::vector<char> buffer(fh.FileSize());
		fh.Read(&buffer[0], buffer.size());

		const bool success = !!ilLoadL(IL_TYPE_UNKNOWN, &buffer[0], buffer.size());

		if (!success) {
			ilDeleteImages(1,&ilheightmap);
			cb->PrintMsg("Failed to load %s", hmfile);
			return NULL;
		}

		const int hmWidth = ilGetInteger(IL_IMAGE_WIDTH);
		const int hmHeight = ilGetInteger (IL_IMAGE_HEIGHT);

		// does it have the correct size? 129,257,513
		int testw = 1;
		while (testw < hmWidth) {
			if (testw + 1 == hmWidth)
				break;
			testw <<= 1;
		}
		if ((testw > hmWidth) || (hmWidth != hmHeight)) {
			cb->PrintMsg("Heightmap %s has wrong dimensions (should be 129x129,257x257...)", hmfile);
			ilDeleteImages(1, &ilheightmap);
			return NULL;
		}

		// convert
		if (!ilConvertImage(IL_LUMINANCE, IL_UNSIGNED_SHORT)) {
			cb->PrintMsg("Failed to convert heightmap image (%s) to grayscale image.", hmfile);
			ilDeleteImages(1, &ilheightmap);
			return NULL;
		}

		// copy the data into the highest detail heightmap
		Heightmap* hm = new Heightmap;
		hm->Alloc(hmWidth, hmHeight);
		ushort* imgData = (ushort*) ilGetData();

		for (int y = 0; y < hmWidth * hmHeight; y++) {
			hm->dataSynced[y] = imgData[y] / float((1 << (sizeof(short) * 8)) - 1);
			hm->dataUnsynced[y] = hm->dataSynced[y];
		}

		// heightmap is copied, so the original image can be deleted
		ilDeleteImages(1, &ilheightmap);
		return hm;
	}

	Vector3 Terrain::TerrainSize()
	{
		return Vector3(heightmap->w, 0.0f, heightmap->h) * SquareSize;
	}

	int Terrain::GetHeightmapWidth() const { return heightmap->w; }
	int Terrain::GetHeightmapHeight() const { return heightmap->h; }

	void Terrain::SetShaderParams(Vector3 dir, Vector3 eyevec)
	{
		texturing->SetShaderParams(dir, eyevec);
	}




	// heightmap blitting
	void Terrain::HeightMapUpdatedUnsynced(int sx, int sy, int w, int h)
	{
		// clip
		if (sx < 0) sx = 0;
		if (sy < 0) sy = 0;
		if (sx + w > heightmap->w) w = heightmap->w - sx;
		if (sy + h > heightmap->h) h = heightmap->h - sy;

		// mark for vertex buffer update
		renderDataManager->UpdateRect(sx, sy, w, h);

		// update heightmap mipmap chain
		// NOTE:
		//     this writes to dataSynced for all heightmaps in the
		//     lowDetail-chain at depth > 0, but these are _NEVER_
		//     accessed in synced context (neither are any nodes
		//     in the highDetail chain) - ONLY the top-level node
		//     (this->heightmap) carries the actual sync-relevant
		//     height values
		// TODO:
		//     this should also update {face,center}NormalsUnsynced
		//     like SMFReadMap does; currently they are initialized
		//     only once (in ReadMap::UpdateFaceNormals)
		heightmap->UpdateLowerUnsynced(sx, sy, w, h);

		Update();
		CacheTextures();
	}

	std::vector<float>& Terrain::GetCornerHeightMapSynced()   { return heightmap->dataSynced; }
	std::vector<float>& Terrain::GetCornerHeightMapUnsynced() { return heightmap->dataUnsynced; }


	void Terrain::SetShadowParams(ShadowMapParams* smp)
	{
		texturing->SetShadowMapParams(smp);
	}

	RenderContext* Terrain::AddRenderContext(Camera* cam, bool needsTexturing)
	{
		RenderContext* rc = new RenderContext;

		rc->cam = cam;
		rc->needsTexturing = needsTexturing;

		contexts.push_back(rc);
		return rc;
	}

	void Terrain::RemoveRenderContext(RenderContext* rc)
	{
		contexts.erase(find(contexts.begin(),contexts.end(),rc));
		delete rc;
	}

	void Terrain::SetActiveContext(RenderContext* rc)
	{
		activeRC = rc;
	}

};