//Author : Subha Sarkar
#include<opencv2/opencv.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>
#include<math.h>
#include<stdio.h>
#include<stdlib.h>
#define RADIUS 150
#define CENTER_Y (IMAGE_HEIGHT/2)
#define CENTER_X (IMAGE_WIDTH/2)
#define IMAGE_HEIGHT 400
#define IMAGE_WIDTH 400
#define WINDOW_NAME "SHADER (ARTIFICIAL MOON) USING C++"
using namespace std;
using namespace cv;
typedef struct
{
double cos_alpha;
double cos_beta;
double cos_gamma;
}cosines;
typedef struct
{
double x;
double y;
double z;
}vect;
Mat image(IMAGE_WIDTH, IMAGE_HEIGHT, CV_8UC1, Scalar(0));
int slider;
const int SLIDER_MAX = 180;
cosines shader[IMAGE_HEIGHT][IMAGE_WIDTH] = { 0 };
double cosz(double, double);
int assign_shader_vector(cosines(*)[IMAGE_WIDTH]);
void slider_function(int, void*);
int main()
{
//int i, j;
namedWindow(WINDOW_NAME);
//imshow(WINDOW_NAME, image);
//radius of the circle is 150 pixels
//Creating the Look up array for the 3D shade effect
assign_shader_vector(shader);
slider = 0;
createTrackbar("ADJUST", WINDOW_NAME, &slider, SLIDER_MAX, slider_function);
while (char(waitKey(1)) != 'q');
return 0;
}
double cosz(double cosx, double cosy)
{
double temp = 0;
temp = 1.00 - cosx*cosx - cosy*cosy;
temp = sqrt(temp);
return temp;
}
int assign_shader_vector(cosines(*shader)[IMAGE_WIDTH])
{
int i = 0;
int j = 0;
for (j = 0;j < IMAGE_HEIGHT;j++)
{
for (i = 0;i < IMAGE_WIDTH;i++)
{
if ((RADIUS * RADIUS) >((i - CENTER_X)*(i - CENTER_X) + (j - CENTER_Y)*(j - CENTER_Y))) // means that the point is inside the circle
{
(*(*(shader + j) + i)).cos_alpha = ((double)i - CENTER_X) / RADIUS;
(*(*(shader + j) + i)).cos_beta = ((double)j - CENTER_Y) / RADIUS;
(*(*(shader + j) + i)).cos_gamma = cosz(((double)i - CENTER_X) / RADIUS, ((double)j - CENTER_Y) / RADIUS);
}
}
}
return 0;
}
void slider_function(int position, void*)
{
double temp;
int i = 0;
int j = 0;
vect v = { 0,0,0 };
v.x = (double)SLIDER_MAX / 2 - (double)position;
v.y = 0.00;
v.z = -(double)30; //this decides the region upto which the artificial light is adjustable
temp = sqrt(v.x*v.x + v.z*v.z);
v.x = v.x / temp;
v.z = v.z / temp;
for (j = 0;j<IMAGE_HEIGHT;j++)
{
for (i = 0;i<IMAGE_WIDTH;i++)
{
if ((*(*(shader + j) + i)).cos_alpha != 0.00 || (*(*(shader + j) + i)).cos_beta != 0.00 || (*(*(shader + j) + i)).cos_gamma != 0.00)
{
temp = (-v.x * ((*(*(shader + j) + i)).cos_alpha) - v.y*((*(*(shader + j) + i)).cos_beta) - v.z*((*(*(shader + j) + i)).cos_gamma));
if (temp > 0.00)
{
image.at<uchar>(j, i) = temp * 255.0;
}
else
{
image.at<uchar>(j, i) = 0;
}
}
}
}
imshow(WINDOW_NAME, image);
return;
}