Daviddoria: Created page with '==ColorPick.cxx== #include #include #include #include #include void display(); void LookAt(); void DrawCube(cons…'

2010-11-24T00:41:50Z

Created page with '==ColorPick.cxx== <source lang="cpp"> #include <iostream> #include <vector> #include <map> #include <cstdio> #include <glut.h> void display(); void LookAt(); void DrawCube(cons…'

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==ColorPick.cxx==
<source lang="cpp">
#include <iostream>
#include <vector>
#include <map>
#include <cstdio>

#include <glut.h>

void display();
void LookAt();
void DrawCube(const bool PickColors);

#define PICK_BUFFER_SIZE 256
unsigned int PickBuffer[PICK_BUFFER_SIZE];

void Pick(GLdouble x, GLdouble y);

void MouseButtonsPick(int button, int state, int x, int y);
void polygon(int a, int b, int c , int d);

void Array2Vec(unsigned char arr[3], std::vector<unsigned char> &out);
void OutputVector(std::vector<unsigned char> &arr);

int WindowHeight = 1000;
int WindowWidth = 1000;

//vector<vector<unsigned char> > ColorList(256*256*256);
std::map<std::vector<unsigned char>, int> ColorMap;
std::vector<std::vector<unsigned char> > ColorList;
void GenerateColors(std::map<std::vector<unsigned char>, int> &Map, std::vector<std::vector<unsigned char> > &List, int num);

int main(int argc, char *argv[])
{
GenerateColors(ColorMap, ColorList, 10);

glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(WindowWidth, WindowHeight);
glutInitWindowPosition(0, 0);

glutCreateWindow("Picking Example");

glutDisplayFunc(display);
glutMouseFunc(MouseButtonsPick);

glEnable(GL_DEPTH_TEST);

LookAt();
glutMainLoop();
return 0;
}

void GenerateColors(std::map<std::vector<unsigned char>, int> &Map, std::vector<std::vector<unsigned char> > &List, int num)
{
std::vector<unsigned char> junk(3,-1);
List = std::vector<std::vector<unsigned char> > (num + 1, junk);
int ColorIndex = 1;

for(unsigned char r = 1; r <= 255 && r > 0; r++) // or (int)r <= 255
{
//printf("r: %u\n", r);
for(unsigned char g = 1; g <= 255 && g > 0; g++)
{
//printf("g: %u\n", g);
for(unsigned char b = 1; b <= 255 && b>0; b++)
{
//printf("b: %u\n", b);
std::vector<unsigned char> color(3,0);
color[0] = r;
color[1] = g;
color[2] = b;

Map[color] = ColorIndex;
List[ColorIndex] = color;
//ColorList.push_back(color);

ColorIndex++;
if(ColorIndex > num)
{
return;
}
}
}
}

}

void LookAt()
{
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(70, 1, 1, 100);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();

gluLookAt(2, 2, 10, 2, 0, 0, 0, 1, 0);

}

void display()
{
DrawCube(false);

glutSwapBuffers();
}

GLfloat vertices[][3] = {{-1.0,-1.0,-1.0},{1.0,-1.0,-1.0},
{1.0,1.0,-1.0}, {-1.0,1.0,-1.0}, {-1.0,-1.0,1.0},
{1.0,-1.0,1.0}, {1.0,1.0,1.0}, {-1.0,1.0,1.0}};

void DrawCube(const bool PickColors)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

if(PickColors)
{
glDisable(GL_DITHER);
glDisable(GL_LIGHTING);
}
else
{
glEnable(GL_DITHER);
//glEnable(GL_LIGHTING);
}

if(!PickColors)
{
glColor3ub(255, 0, 0); // Color Red
}
else
{
glColor3ub(1, 1, 1);
}

polygon(0,3,2,1);

if(!PickColors)
{
glColor3ub(0,255,0); // Color Green
}
else
{
glColor3ub(1, 1, 2);
}

polygon(2,3,7,6);

if(!PickColors)
{
glColor3ub(0, 0, 255); // Color Blue
}
else
{
glColor3ub(1, 1, 3);
}

polygon(0,4,7,3);

if(!PickColors)
{
glColor3ub(255,255,0); // Color Yellow
}
else
{
glColor3ub(1, 1, 4);
}

polygon(1,2,6,5);

if(!PickColors)
{
glColor3ub(0,255,255); // Color Cyan
}
else
{
glColor3ub(1, 1, 5);
}

polygon(4,5,6,7);

if(!PickColors)
{
glColor3ub(255,0,255); // Color Magenta
}
else
{
glColor3ub(1, 1, 6);
}

polygon(0,1,5,4);
}

void polygon(int a, int b, int c , int d)
{
glBegin(GL_QUADS);
glVertex3fv(vertices[a]);
glVertex3fv(vertices[b]);
glVertex3fv(vertices[c]);
glVertex3fv(vertices[d]);
glEnd();
}

void MouseButtonsPick(int button, int state, int x, int y)
{
if( (state == GLUT_DOWN) && (button == GLUT_LEFT_BUTTON) )
{
double newy = glutGet(GLUT_WINDOW_HEIGHT) - 1 - y;
Pick(x, newy);
}
}

void Pick(GLdouble x, GLdouble y)
{
DrawCube(true);
//glutSwapBuffers();

unsigned char pixelub[3];
glReadPixels(x, y, 1, 1, GL_RGB, GL_UNSIGNED_BYTE, pixelub);

printf("r: %u g: %u b: %u\n", pixelub[0], pixelub[1], pixelub[2]);

std::vector<unsigned char> v(3,0);
Array2Vec(pixelub, v);

printf("r: %u g: %u b: %u\n", v[0], v[1], v[2]);

int c = ColorMap[v];
std::cout << "Color Index: " << c << std::endl;
std::cout << "Corresponding Color: ";
OutputVector(ColorList[c]);
std::cout << std::endl;
}

void Array2Vec(unsigned char arr[3], std::vector<unsigned char> &out)
{
for(int i = 0; i <= 2; i++)
{
out[i] = arr[i];
}

}

void OutputVector(std::vector<unsigned char> &arr)
{
for(int i = 0; i <= 2; i++)
{
std::cout << (int)arr[i] << " " ;
}

std::cout << std::endl;

}

</source>

==CMakeLists.txt==
<source lang="cmake">
cmake_minimum_required(VERSION 2.6)

PROJECT(OpenGLTest)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fopenmp") #g++

INCLUDE_DIRECTORIES(/usr/include/GL/)

LINK_DIRECTORIES(/usr/lib)

ADD_EXECUTABLE(ColorPick ColorPick.cpp
MouseClass.h )

TARGET_LINK_LIBRARIES(ColorPick glut GLU GL Xmu X11)

</source>

OpenGL/ColorPick - Revision history

Daviddoria: Created page with '==ColorPick.cxx== #include #include #include #include #include void display(); void LookAt(); void DrawCube(cons…'