ElevationColorMap.cpp

/***********************************************************************
ElevationColorMap - Class to represent elevation color maps for
topographic maps.
Copyright (c) 2014-2016 Oliver Kreylos

This file is part of the Augmented Reality Sandbox (SARndbox).

The Augmented Reality Sandbox is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The Augmented Reality Sandbox is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License along
with the Augmented Reality Sandbox; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
***********************************************************************/

#include "ElevationColorMap.h"

#include <string>
#include <Misc/ThrowStdErr.h>
#include <Misc/FileNameExtensions.h>
#include <IO/ValueSource.h>
#include <GL/gl.h>
#include <GL/GLContextData.h>
#include <GL/Extensions/GLARBShaderObjects.h>
#include <Vrui/OpenFile.h>

#include "Types.h"
#include "DepthImageRenderer.h"

#include "Config.h"

/**********************************
Methods of class ElevationColorMap:
**********************************/

ElevationColorMap::ElevationColorMap(const char* heightMapName)
	{
	/* Load the given height map: */
	load(heightMapName);
	}

void ElevationColorMap::initContext(GLContextData& contextData) const
	{
	/* Initialize required OpenGL extensions: */
	GLARBShaderObjects::initExtension();
	
	/* Create the data item and associate it with this object: */
	DataItem* dataItem=new DataItem;
	contextData.addDataItem(this,dataItem);
	}

void ElevationColorMap::load(const char* heightMapName)
	{
	/* Open the height map file: */
	std::string fullHeightMapName;
	if(heightMapName[0]=='/')
		{
		/* Use the absolute file name directly: */
		fullHeightMapName=heightMapName;
		}
	else
		{
		/* Assemble a file name relative to the configuration file directory: */
		fullHeightMapName=CONFIG_CONFIGDIR;
		fullHeightMapName.push_back('/');
		fullHeightMapName.append(heightMapName);
		}
	
	/* Open the height map file: */
	IO::ValueSource heightMapSource(Vrui::openFile(fullHeightMapName.c_str()));
	
	/* Load the height color map: */
	std::vector<Color> heightMapColors;
	std::vector<GLdouble> heightMapKeys;
	if(Misc::hasCaseExtension(heightMapName,".cpt"))
		{
		heightMapSource.setPunctuation("\n");
		heightMapSource.skipWs();
		int line=1;
		while(!heightMapSource.eof())
			{
			/* Read the next color map key value: */
			heightMapKeys.push_back(GLdouble(heightMapSource.readNumber()));
			
			/* Read the next color map color value: */
			Color color;
			for(int i=0;i<3;++i)
				color[i]=Color::Scalar(heightMapSource.readNumber()/255.0);
			color[3]=Color::Scalar(1);
			heightMapColors.push_back(color);
			
			if(!heightMapSource.isLiteral('\n'))
				Misc::throwStdErr("ElevationColorMap: Color map format error in line %d of file %s",line,fullHeightMapName.c_str());
			++line;
			}
		}
	else
		{
		heightMapSource.setPunctuation(",\n");
		heightMapSource.skipWs();
		int line=1;
		while(!heightMapSource.eof())
			{
			/* Read the next color map key value: */
			heightMapKeys.push_back(GLdouble(heightMapSource.readNumber()));
			if(!heightMapSource.isLiteral(','))
				Misc::throwStdErr("ElevationColorMap: Color map format error in line %d of file %s",line,fullHeightMapName.c_str());
			
			/* Read the next color map color value: */
			Color color;
			for(int i=0;i<3;++i)
				color[i]=Color::Scalar(heightMapSource.readNumber());
			color[3]=Color::Scalar(1);
			heightMapColors.push_back(color);
			
			if(!heightMapSource.isLiteral('\n'))
				Misc::throwStdErr("ElevationColorMap: Color map format error in line %d of file %s",line,fullHeightMapName.c_str());
			++line;
			}
		}
	
	/* Create the color map: */
	setColors(heightMapKeys.size(),&heightMapColors[0],&heightMapKeys[0],256);
	
	/* Invalidate the color map texture object: */
	++textureVersion;
	}

void ElevationColorMap::calcTexturePlane(const Plane& basePlane)
	{
	/* Scale and offset the camera-space base plane equation: */
	const Plane::Vector& bpn=basePlane.getNormal();
	Scalar bpo=basePlane.getOffset();
	Scalar hms=Scalar(getNumEntries()-1)/((getScalarRangeMax()-getScalarRangeMin())*Scalar(getNumEntries()));
	Scalar hmo=Scalar(0.5)/Scalar(getNumEntries())-hms*getScalarRangeMin();
	for(int i=0;i<3;++i)
		texturePlaneEq[i]=GLfloat(bpn[i]*hms);
	texturePlaneEq[3]=GLfloat(-bpo*hms+hmo);
	}

void ElevationColorMap::calcTexturePlane(const DepthImageRenderer* depthImageRenderer)
	{
	/* Calculate texture plane based on the given depth image renderer's base plane: */
	calcTexturePlane(depthImageRenderer->getBasePlane());
	}

void ElevationColorMap::bindTexture(GLContextData& contextData) const
	{
	/* Retrieve the data item: */
	DataItem* dataItem=contextData.retrieveDataItem<DataItem>(this);
	
	/* Bind the texture object: */
	glBindTexture(GL_TEXTURE_1D,dataItem->textureObjectId);
	
	/* Check if the color map texture is outdated: */
	if(dataItem->textureObjectVersion!=textureVersion)
		{
		/* Upload the color map entries as a 1D texture: */
		glTexParameteri(GL_TEXTURE_1D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
		glTexParameteri(GL_TEXTURE_1D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
		glTexParameteri(GL_TEXTURE_1D,GL_TEXTURE_WRAP_S,GL_CLAMP_TO_EDGE);
		glTexImage1D(GL_TEXTURE_1D,0,GL_RGB8,getNumEntries(),0,GL_RGBA,GL_FLOAT,getColors());
		
		dataItem->textureObjectVersion=textureVersion;
		}
	}

void ElevationColorMap::uploadTexturePlane(GLint location) const
	{
	/* Upload the texture mapping plane equation: */
	glUniformARB<4>(location,1,texturePlaneEq);
	}