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

Shared terrain source model

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

#include "precompiled.h"
#pragma hdrstop

#include "TerrainModel.h"

idTerrainPatch::idTerrainPatch() {
	name.Clear();
	material.Clear();
	origin.Zero();
	width = TERRAIN_DEFAULT_VERTS;
	height = TERRAIN_DEFAULT_VERTS;
	cellSize = TERRAIN_DEFAULT_CELL_SIZE;
	paintWidth = TERRAIN_DEFAULT_PAINT_SIZE;
	paintHeight = TERRAIN_DEFAULT_PAINT_SIZE;
	paintTexture = 0;
	paintTextureDirty = true;
	paintDirtyMinX = 0;
	paintDirtyMinY = 0;
	paintDirtyMaxX = paintWidth - 1;
	paintDirtyMaxY = paintHeight - 1;
	bounds.Clear();
}

int idTerrainPatch::SampleIndex( int x, int y ) const {
	return y * width + x;
}

int idTerrainPatch::PaintIndex( int x, int y ) const {
	return y * paintWidth + x;
}

float idTerrainPatch::SampleHeight( int x, int y ) const {
	return heights[SampleIndex( x, y )];
}

void idTerrainPatch::SetHeight( int x, int y, float height ) {
	heights[SampleIndex( x, y )] = height;
}

bool idTerrainPatch::SetHeightBySample( int sample, float height ) {
	if ( sample < 0 || sample >= heights.Num() ) {
		return false;
	}
	heights[sample] = height;
	return true;
}

idVec4 idTerrainPatch::SamplePaintWeight( int x, int y ) const {
	return paintWeights[PaintIndex( x, y )];
}

void idTerrainPatch::SetPaintWeight( int x, int y, const idVec4 &weight ) {
	paintWeights[PaintIndex( x, y )] = NormalizeLayerWeight( weight );
	MarkPaintTextureDirtyRect( x, y, x, y );
}

bool idTerrainPatch::SetPaintWeightBySample( int sample, const idVec4 &weight ) {
	if ( sample < 0 || sample >= paintWeights.Num() || paintWidth <= 0 ) {
		return false;
	}
	paintWeights[sample] = NormalizeLayerWeight( weight );
	MarkPaintTextureDirtyRect( sample % paintWidth, sample / paintWidth, sample % paintWidth, sample / paintWidth );
	return true;
}

idVec4 idTerrainPatch::BaseLayerWeight() {
	return idVec4( 1.0f, 0.0f, 0.0f, 0.0f );
}

idVec4 idTerrainPatch::NormalizeLayerWeight( const idVec4 &weight ) {
	idVec4 normalized;
	normalized.x = weight.x > 0.0f ? weight.x : 0.0f;
	normalized.y = weight.y > 0.0f ? weight.y : 0.0f;
	normalized.z = weight.z > 0.0f ? weight.z : 0.0f;
	normalized.w = weight.w > 0.0f ? weight.w : 0.0f;

	const float total = normalized.x + normalized.y + normalized.z + normalized.w;
	if ( total <= 0.0001f ) {
		return BaseLayerWeight();
	}

	const float invTotal = 1.0f / total;
	normalized.x *= invTotal;
	normalized.y *= invTotal;
	normalized.z *= invTotal;
	normalized.w *= invTotal;
	return normalized;
}

float idTerrainPatch::WorldWidth() const {
	return ( width - 1 ) * cellSize;
}

float idTerrainPatch::WorldHeight() const {
	return ( height - 1 ) * cellSize;
}

float idTerrainPatch::BilinearHeight( float u, float v ) const {
	u = idMath::ClampFloat( 0.0f, 1.0f, u );
	v = idMath::ClampFloat( 0.0f, 1.0f, v );

	const float fx = u * ( width - 1 );
	const float fy = v * ( height - 1 );
	const int x0 = idMath::ClampInt( 0, width - 1, (int)floorf( fx ) );
	const int y0 = idMath::ClampInt( 0, height - 1, (int)floorf( fy ) );
	const int x1 = idMath::ClampInt( 0, width - 1, x0 + 1 );
	const int y1 = idMath::ClampInt( 0, height - 1, y0 + 1 );
	const float tx = fx - (float)x0;
	const float ty = fy - (float)y0;

	const float h00 = SampleHeight( x0, y0 );
	const float h10 = SampleHeight( x1, y0 );
	const float h01 = SampleHeight( x0, y1 );
	const float h11 = SampleHeight( x1, y1 );
	const float h0 = h00 + ( h10 - h00 ) * tx;
	const float h1 = h01 + ( h11 - h01 ) * tx;
	return h0 + ( h1 - h0 ) * ty;
}

idVec3 idTerrainPatch::VertexUV( float u, float v ) const {
	idVec3 p;
	p.x = origin.x + WorldWidth() * u;
	p.y = origin.y + WorldHeight() * v;
	p.z = origin.z + BilinearHeight( u, v );
	return p;
}

idVec3 idTerrainPatch::Vertex( int x, int y ) const {
	idVec3 v;
	v.x = origin.x + x * cellSize;
	v.y = origin.y + y * cellSize;
	v.z = origin.z + SampleHeight( x, y );
	return v;
}

idVec3 idTerrainPatch::VertexNormal( int x, int y ) const {
	const int x0 = idMath::ClampInt( 0, width - 1, x - 1 );
	const int x1 = idMath::ClampInt( 0, width - 1, x + 1 );
	const int y0 = idMath::ClampInt( 0, height - 1, y - 1 );
	const int y1 = idMath::ClampInt( 0, height - 1, y + 1 );
	const idVec3 sx = Vertex( x1, y ) - Vertex( x0, y );
	const idVec3 sy = Vertex( x, y1 ) - Vertex( x, y0 );
	idVec3 normal = sx.Cross( sy );
	if ( normal.LengthSqr() <= 0.0001f ) {
		normal.Set( 0.0f, 0.0f, 1.0f );
	} else {
		normal.Normalize();
	}
	return normal;
}

void idTerrainPatch::UpdateBounds() {
	bounds.Clear();
	if ( width <= 0 || height <= 0 ) {
		bounds.AddPoint( origin );
		return;
	}
	for ( int y = 0; y < height; y++ ) {
		for ( int x = 0; x < width; x++ ) {
			bounds.AddPoint( Vertex( x, y ) );
		}
	}
}

void idTerrainPatch::EnsureLayerData( const char *defaultMaterial ) {
	if ( material.IsEmpty() ) {
		material = defaultMaterial && defaultMaterial[0] ? defaultMaterial : "textures/common/caulk";
	}
	if ( layerMaterials[0].IsEmpty() ) {
		layerMaterials[0] = material;
	}
	material = layerMaterials[0];

	if ( width < 2 ) {
		width = 2;
	}
	if ( height < 2 ) {
		height = 2;
	}
	const int heightSampleCount = width * height;
	const int oldHeightCount = heights.Num();
	heights.SetNum( heightSampleCount );
	for ( int i = oldHeightCount; i < heightSampleCount; i++ ) {
		heights[i] = 0.0f;
	}

	if ( paintWidth < 2 ) {
		paintWidth = TERRAIN_DEFAULT_PAINT_SIZE;
	}
	if ( paintHeight < 2 ) {
		paintHeight = TERRAIN_DEFAULT_PAINT_SIZE;
	}

	const int paintSampleCount = paintWidth * paintHeight;
	if ( paintSampleCount <= 0 ) {
		paintWeights.Clear();
		return;
	}

	const int oldCount = paintWeights.Num();
	paintWeights.SetNum( paintSampleCount );
	if ( oldCount != paintSampleCount ) {
		MarkPaintTextureDirty();
	}
	for ( int i = 0; i < paintSampleCount; i++ ) {
		if ( i >= oldCount ) {
			paintWeights[i] = BaseLayerWeight();
		} else {
			paintWeights[i] = NormalizeLayerWeight( paintWeights[i] );
		}
	}
	UpdateBounds();
}

void idTerrainPatch::ClearLayerWeight( int layer ) {
	if ( layer < 0 || layer >= TERRAIN_MAX_LAYERS ) {
		return;
	}
	for ( int i = 0; i < paintWeights.Num(); i++ ) {
		idVec4 weight = paintWeights[i];
		weight[layer] = 0.0f;
		paintWeights[i] = NormalizeLayerWeight( weight );
	}
	MarkPaintTextureDirty();
}

bool idTerrainPatch::SetLayerMaterials( const idStr newLayerMaterials[TERRAIN_MAX_LAYERS], const char *defaultMaterial ) {
	bool changed = false;
	for ( int layer = 0; layer < TERRAIN_MAX_LAYERS; layer++ ) {
		idStr materialName = newLayerMaterials[layer];
		materialName.StripLeading( ' ' );
		materialName.StripTrailing( ' ' );
		if ( layer == 0 && materialName.IsEmpty() ) {
			materialName = defaultMaterial && defaultMaterial[0] ? defaultMaterial : "textures/common/caulk";
		}
		if ( layerMaterials[layer].Icmp( materialName.c_str() ) == 0 ) {
			continue;
		}
		layerMaterials[layer] = materialName;
		if ( layer > 0 && materialName.IsEmpty() ) {
			ClearLayerWeight( layer );
		}
		changed = true;
	}
	material = layerMaterials[0];
	return changed;
}

void idTerrainPatch::MarkPaintTextureDirty() {
	paintTextureDirty = true;
	paintDirtyMinX = 0;
	paintDirtyMinY = 0;
	paintDirtyMaxX = paintWidth > 0 ? paintWidth - 1 : 0;
	paintDirtyMaxY = paintHeight > 0 ? paintHeight - 1 : 0;
}

void idTerrainPatch::ClearPaintTextureDirtyRect() {
	paintTextureDirty = false;
	paintDirtyMinX = paintWidth;
	paintDirtyMinY = paintHeight;
	paintDirtyMaxX = -1;
	paintDirtyMaxY = -1;
}

void idTerrainPatch::MarkPaintTextureDirtyRect( int minX, int minY, int maxX, int maxY ) {
	if ( paintWidth <= 0 || paintHeight <= 0 ) {
		return;
	}

	minX = idMath::ClampInt( 0, paintWidth - 1, minX );
	maxX = idMath::ClampInt( 0, paintWidth - 1, maxX );
	minY = idMath::ClampInt( 0, paintHeight - 1, minY );
	maxY = idMath::ClampInt( 0, paintHeight - 1, maxY );
	if ( maxX < minX || maxY < minY ) {
		return;
	}

	if ( !paintTextureDirty || paintDirtyMaxX < paintDirtyMinX || paintDirtyMaxY < paintDirtyMinY ) {
		paintDirtyMinX = minX;
		paintDirtyMinY = minY;
		paintDirtyMaxX = maxX;
		paintDirtyMaxY = maxY;
	} else {
		if ( minX < paintDirtyMinX ) {
			paintDirtyMinX = minX;
		}
		if ( minY < paintDirtyMinY ) {
			paintDirtyMinY = minY;
		}
		if ( maxX > paintDirtyMaxX ) {
			paintDirtyMaxX = maxX;
		}
		if ( maxY > paintDirtyMaxY ) {
			paintDirtyMaxY = maxY;
		}
	}
	paintTextureDirty = true;
}

idTerrainModel::idTerrainModel() {
}

idTerrainModel::~idTerrainModel() {
	Clear();
}

void idTerrainModel::Clear() {
	terrains.DeleteContents( true );
}

int idTerrainModel::NumTerrains() const {
	return terrains.Num();
}

idTerrainPatch *idTerrainModel::Terrain( int index ) {
	if ( index < 0 || index >= terrains.Num() ) {
		return NULL;
	}
	return terrains[index];
}

const idTerrainPatch *idTerrainModel::Terrain( int index ) const {
	if ( index < 0 || index >= terrains.Num() ) {
		return NULL;
	}
	return terrains[index];
}

idList<idTerrainPatch *> &idTerrainModel::Terrains() {
	return terrains;
}

const idList<idTerrainPatch *> &idTerrainModel::Terrains() const {
	return terrains;
}

static float TerrainModel_SnapToGrid( float value, float gridSize ) {
	if ( gridSize <= 0.0f ) {
		gridSize = 1.0f;
	}
	return floorf( value / gridSize + ( value >= 0.0f ? 0.5f : -0.5f ) ) * gridSize;
}

idTerrainPatch *idTerrainModel::AllocDefaultTerrain( const idVec3 &center, const char *defaultMaterial, float gridSize ) {
	idTerrainPatch *terrain = new idTerrainPatch;
	terrain->name = va( "terrain_%i", terrains.Num() + 1 );
	terrain->material = defaultMaterial && defaultMaterial[0] ? defaultMaterial : "textures/common/caulk";
	terrain->layerMaterials[0] = terrain->material;
	const float worldSize = ( terrain->width - 1 ) * terrain->cellSize;
	terrain->origin.x = TerrainModel_SnapToGrid( center.x - worldSize * 0.5f, gridSize );
	terrain->origin.y = TerrainModel_SnapToGrid( center.y - worldSize * 0.5f, gridSize );
	terrain->origin.z = TerrainModel_SnapToGrid( center.z, gridSize );
	terrain->heights.SetNum( terrain->width * terrain->height );
	for ( int i = 0; i < terrain->heights.Num(); i++ ) {
		terrain->heights[i] = 0.0f;
	}
	terrain->EnsureLayerData( defaultMaterial );
	return terrain;
}

void idTerrainModel::AddTerrain( idTerrainPatch *terrain ) {
	if ( terrain ) {
		terrains.Append( terrain );
	}
}

idStr idTerrainModel::FileNameForMap( const char *mapFileName ) {
	idStr fileName = mapFileName ? mapFileName : "";
	fileName.StripFileExtension();
	fileName.SetFileExtension( ".terrain" );
	return fileName;
}

bool idTerrainModel::SaveFile( const char *filename ) {
	if ( !filename || !filename[0] ) {
		return false;
	}

	const bool osPath = strstr( filename, ":" ) != NULL;
	idFile *file = osPath ? fileSystem->OpenExplicitFileWrite( filename ) : fileSystem->OpenFileWrite( filename );
	if ( !file ) {
		common->Warning( "idTerrainModel::SaveFile: couldn't write %s", filename );
		return false;
	}

	file->WriteFloatString( "terrainAuthoring 3 {\n" );
	for ( int i = 0; i < terrains.Num(); i++ ) {
		idTerrainPatch *terrain = terrains[i];
		if ( !terrain ) {
			continue;
		}
		terrain->EnsureLayerData( "textures/common/caulk" );

		file->WriteFloatString( "\tterrain {\n" );
		file->WriteFloatString( "\t\tname \"%s\"\n", terrain->name.c_str() );
		file->WriteFloatString( "\t\tmaterial \"%s\"\n", terrain->material.c_str() );
		for ( int layer = 0; layer < TERRAIN_MAX_LAYERS; layer++ ) {
			if ( layer == 0 || !terrain->layerMaterials[layer].IsEmpty() ) {
				file->WriteFloatString( "\t\tlayer %i \"%s\"\n", layer, terrain->layerMaterials[layer].c_str() );
			}
		}
		file->WriteFloatString( "\t\torigin ( %f %f %f )\n", terrain->origin.x, terrain->origin.y, terrain->origin.z );
		file->WriteFloatString( "\t\tsize %i %i\n", terrain->width, terrain->height );
		file->WriteFloatString( "\t\tcellSize %f\n", terrain->cellSize );
		file->WriteFloatString( "\t\tpaintSize %i %i\n", terrain->paintWidth, terrain->paintHeight );
		file->WriteFloatString( "\t\theights {\n" );
		for ( int y = 0; y < terrain->height; y++ ) {
			file->WriteFloatString( "\t\t\t" );
			for ( int x = 0; x < terrain->width; x++ ) {
				file->WriteFloatString( "%f ", terrain->SampleHeight( x, y ) );
			}
			file->WriteFloatString( "\n" );
		}
		file->WriteFloatString( "\t\t}\n" );
		file->WriteFloatString( "\t\tpaintWeights {\n" );
		for ( int y = 0; y < terrain->paintHeight; y++ ) {
			file->WriteFloatString( "\t\t\t" );
			for ( int x = 0; x < terrain->paintWidth; x++ ) {
				const idVec4 weights = terrain->SamplePaintWeight( x, y );
				file->WriteFloatString( "%f %f %f %f ", weights.x, weights.y, weights.z, weights.w );
			}
			file->WriteFloatString( "\n" );
		}
		file->WriteFloatString( "\t\t}\n" );
		file->WriteFloatString( "\t}\n" );
	}
	file->WriteFloatString( "}\n" );
	fileSystem->CloseFile( file );
	return true;
}

bool idTerrainModel::LoadFile( const char *filename, const char *defaultMaterial ) {
	Clear();
	if ( !filename || !filename[0] ) {
		return false;
	}

	const char *fallbackMaterial = defaultMaterial && defaultMaterial[0] ? defaultMaterial : "textures/common/caulk";
	const bool osPath = strstr( filename, ":" ) != NULL;
	idLexer src( LEXFL_NOSTRINGCONCAT | LEXFL_NODOLLARPRECOMPILE | LEXFL_ALLOWPATHNAMES );
	src.LoadFile( filename, osPath );
	if ( !src.IsLoaded() ) {
		return false;
	}

	idToken token;
	if ( !src.ReadToken( &token ) || token.Icmp( "terrainAuthoring" ) ) {
		return false;
	}
	src.ReadToken( &token );
	if ( token != "{" ) {
		src.ExpectTokenString( "{" );
	}

	while ( src.ReadToken( &token ) ) {
		if ( token == "}" ) {
			break;
		}
		if ( token.Icmp( "terrain" ) ) {
			break;
		}

		idTerrainPatch *terrain = new idTerrainPatch;
		terrain->name = va( "terrain_%i", terrains.Num() + 1 );
		terrain->material = fallbackMaterial;
		terrain->layerMaterials[0] = terrain->material;
		terrain->MarkPaintTextureDirty();

		src.ExpectTokenString( "{" );
		while ( src.ReadToken( &token ) ) {
			if ( token == "}" ) {
				break;
			}
			if ( !token.Icmp( "name" ) ) {
				src.ExpectAnyToken( &token );
				terrain->name = token;
			} else if ( !token.Icmp( "material" ) ) {
				src.ExpectAnyToken( &token );
				terrain->material = token;
				terrain->layerMaterials[0] = token;
			} else if ( !token.Icmp( "layer" ) ) {
				const int layer = src.ParseInt();
				src.ExpectAnyToken( &token );
				if ( layer >= 0 && layer < TERRAIN_MAX_LAYERS ) {
					terrain->layerMaterials[layer] = token;
					if ( layer == 0 ) {
						terrain->material = token;
					}
				}
			} else if ( !token.Icmp( "origin" ) ) {
				src.Parse1DMatrix( 3, terrain->origin.ToFloatPtr() );
			} else if ( !token.Icmp( "size" ) ) {
				terrain->width = src.ParseInt();
				terrain->height = src.ParseInt();
				if ( terrain->width < 2 ) {
					terrain->width = 2;
				}
				if ( terrain->height < 2 ) {
					terrain->height = 2;
				}
			} else if ( !token.Icmp( "cellSize" ) ) {
				terrain->cellSize = src.ParseFloat();
				if ( terrain->cellSize <= 0.0f ) {
					terrain->cellSize = TERRAIN_DEFAULT_CELL_SIZE;
				}
			} else if ( !token.Icmp( "paintSize" ) ) {
				terrain->paintWidth = src.ParseInt();
				terrain->paintHeight = src.ParseInt();
				if ( terrain->paintWidth < 2 ) {
					terrain->paintWidth = 2;
				}
				if ( terrain->paintHeight < 2 ) {
					terrain->paintHeight = 2;
				}
			} else if ( !token.Icmp( "heights" ) ) {
				src.ExpectTokenString( "{" );
				terrain->heights.SetNum( terrain->width * terrain->height );
				for ( int i = 0; i < terrain->heights.Num(); i++ ) {
					terrain->heights[i] = 0.0f;
				}
				int sample = 0;
				while ( src.ReadToken( &token ) ) {
					if ( token == "}" ) {
						break;
					}
					if ( sample < terrain->heights.Num() ) {
						terrain->heights[sample++] = (float)atof( token.c_str() );
					}
				}
			} else if ( !token.Icmp( "weights" ) || !token.Icmp( "paintWeights" ) ) {
				const bool legacyWeights = !token.Icmp( "weights" );
				src.ExpectTokenString( "{" );
				if ( legacyWeights && terrain->paintWidth == TERRAIN_DEFAULT_PAINT_SIZE && terrain->paintHeight == TERRAIN_DEFAULT_PAINT_SIZE ) {
					terrain->paintWidth = terrain->width;
					terrain->paintHeight = terrain->height;
				}
				terrain->paintWeights.SetNum( terrain->paintWidth * terrain->paintHeight );
				for ( int i = 0; i < terrain->paintWeights.Num(); i++ ) {
					terrain->paintWeights[i] = idTerrainPatch::BaseLayerWeight();
				}

				int sample = 0;
				int component = 0;
				idVec4 weight;
				weight.Zero();
				while ( src.ReadToken( &token ) ) {
					if ( token == "}" ) {
						break;
					}
					weight[component++] = (float)atof( token.c_str() );
					if ( component == 4 ) {
						if ( sample < terrain->paintWeights.Num() ) {
							terrain->paintWeights[sample] = idTerrainPatch::NormalizeLayerWeight( weight );
						}
						sample++;
						component = 0;
						weight.Zero();
					}
				}
			}
		}

		terrain->EnsureLayerData( fallbackMaterial );
		terrain->MarkPaintTextureDirty();
		terrain->UpdateBounds();
		terrains.Append( terrain );
	}

	return true;
}