iGraphics.h

//
//  Original Author: S. M. Shahriar Nirjon
//
//  Last Modified by: Mr. Mohammad Imrul Jubair [Assistant Professor (AUST CSE)]
//  Last Updated: 16 December 2017 
//
//  Version: 4.0
//

# include <stdio.h>
# include <stdlib.h>
#pragma comment(lib, "glut32.lib")
#pragma comment(lib, "glaux.lib")
#include "glut.h"
#include <time.h>
#include <math.h>
#include <windows.h>
#include "glaux.h"
# define STB_IMAGE_IMPLEMENTATION
# include "stb_image.h"

int iScreenHeight, iScreenWidth;
int iMouseX, iMouseY;
int ifft=0;
void (*iAnimFunction[10])(void)={0};
int iAnimCount=0;
int iAnimDelays[10];
int iAnimPause[10];

void iDraw();
void iKeyboard(unsigned char);
void iSpecialKeyboard(unsigned char);
void iMouseMove(int, int);
void iPassiveMouseMove(int, int);
void iMouse(int button, int state, int x, int y);

static void  __stdcall iA0(HWND,unsigned int, unsigned int, unsigned long){if(!iAnimPause[0])iAnimFunction[0]();}
static void  __stdcall iA1(HWND,unsigned int, unsigned int, unsigned long){if(!iAnimPause[1])iAnimFunction[1]();}
static void  __stdcall iA2(HWND,unsigned int, unsigned int, unsigned long){if(!iAnimPause[2])iAnimFunction[2]();}
static void  __stdcall iA3(HWND,unsigned int, unsigned int, unsigned long){if(!iAnimPause[3])iAnimFunction[3]();}
static void  __stdcall iA4(HWND,unsigned int, unsigned int, unsigned long){if(!iAnimPause[4])iAnimFunction[4]();}
static void  __stdcall iA5(HWND,unsigned int, unsigned int, unsigned long){if(!iAnimPause[5])iAnimFunction[5]();}
static void  __stdcall iA6(HWND,unsigned int, unsigned int, unsigned long){if(!iAnimPause[6])iAnimFunction[6]();}
static void  __stdcall iA7(HWND,unsigned int, unsigned int, unsigned long){if(!iAnimPause[7])iAnimFunction[7]();}
static void  __stdcall iA8(HWND,unsigned int, unsigned int, unsigned long){if(!iAnimPause[8])iAnimFunction[8]();}
static void  __stdcall iA9(HWND,unsigned int, unsigned int, unsigned long){if(!iAnimPause[9])iAnimFunction[9]();}

int iSetTimer(int msec, void (*f)(void))
{
    int i = iAnimCount;

    if(iAnimCount>=10){printf("Error: Maximum number of already timer used.\n");return -1;}

    iAnimFunction[i] = f;
    iAnimDelays[i] = msec;
    iAnimPause[i] = 0;

    if(iAnimCount == 0) SetTimer(0, 0, msec, iA0);
    if(iAnimCount == 1) SetTimer(0, 0, msec, iA1);
    if(iAnimCount == 2) SetTimer(0, 0, msec, iA2);
    if(iAnimCount == 3) SetTimer(0, 0, msec, iA3);
    if(iAnimCount == 4) SetTimer(0, 0, msec, iA4);

    if(iAnimCount == 5) SetTimer(0, 0, msec, iA5);
    if(iAnimCount == 6) SetTimer(0, 0, msec, iA6);
    if(iAnimCount == 7) SetTimer(0, 0, msec, iA7);
    if(iAnimCount == 8) SetTimer(0, 0, msec, iA8);
    if(iAnimCount == 9) SetTimer(0, 0, msec, iA9);
    iAnimCount++;

    return iAnimCount-1;
}

void iPauseTimer(int index){
    if(index>=0 && index <iAnimCount){
        iAnimPause[index] = 1;
    }
}

void iResumeTimer(int index){
    if(index>=0 && index <iAnimCount){
        iAnimPause[index] = 0;
    }
}

//
// Puts a BMP image on screen
//
// parameters:
//  x - x coordinate
//  y - y coordinate
//  filename - name of the BMP file
//  ignoreColor - A specified color that should not be rendered. If you have an
//                image strip that should be rendered on top of another back
//                ground image, then the background of the image strip should
//                not get rendered. Use the background color of the image strip
//                in ignoreColor parameter. Then the strip's background does
//                not get rendered.
//
//                To disable this feature, put -1 in this parameter
//
void iShowBMP2(int x, int y, char filename[], int ignoreColor)
{
    AUX_RGBImageRec *TextureImage;
    TextureImage = auxDIBImageLoad(filename);

    int i,j;
    int width = TextureImage->sizeX;
    int height = TextureImage->sizeY;
    int nPixels = width * height;
    int *rgPixels = new int[nPixels];

    for (i = 0, j=0; i < nPixels; i++, j += 3)
    {
        int rgb = 0;
        for(int k = 2; k >= 0; k--)
        {
            rgb = ((rgb << 8) | TextureImage->data[j+k]);
        }

        rgPixels[i] = (rgb == ignoreColor) ? 0 : 255;
        rgPixels[i] = ((rgPixels[i] << 24) | rgb);
    }

    glRasterPos2f(x, y);
    glDrawPixels(width, height, GL_RGBA, GL_UNSIGNED_BYTE, rgPixels);

    delete []rgPixels;
    free(TextureImage->data);
    free(TextureImage);
}

void iShowBMP(int x, int y, char filename[])
{
    iShowBMP2(x, y, filename, -1 /* ignoreColor */);
}

unsigned int iLoadImage(char filename[])
{
	int width, height, bpp;

	unsigned int texture;

	BYTE* data(0);
	data = stbi_load(filename, &width, &height, &bpp, 4);
	glGenTextures(1, &texture);
	glBindTexture(GL_TEXTURE_2D, texture);
	glTexImage2D(GL_TEXTURE_2D,
		0,
		GL_RGBA,
		width, height,
		0,
		GL_RGBA,
		GL_UNSIGNED_BYTE,
		data);

	stbi_image_free(data);

	return texture;
}

void iShowImage(int x, int y, int width, int height, unsigned int texture)
{

	glEnable(GL_TEXTURE_2D);

	glBindTexture(GL_TEXTURE_2D, texture);

	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

	glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

	glBegin(GL_QUADS);

		glTexCoord2f(0, 0);
		glVertex2f(x, y);

		glTexCoord2f(1, 0);
		glVertex2f(x + width, y);

		glTexCoord2f(1, -1);
		glVertex2f(x + width, y+height);

		glTexCoord2f(0, -1);
		glVertex2f(x, y + height);

	glEnd();

	glDisable(GL_TEXTURE_2D);

}

void iGetPixelColor (int cursorX, int cursorY, int rgb[])
{
    GLubyte pixel[3];
    glReadPixels(cursorX, cursorY,1,1,
        GL_RGB,GL_UNSIGNED_BYTE,(void *)pixel);

    rgb[0] = pixel[0];
    rgb[1] = pixel[1];
    rgb[2] = pixel[2];

    //printf("%d %d %d\n",pixel[0],pixel[1],pixel[2]);
}

void iText(GLdouble x, GLdouble y, char *str, void* font=GLUT_BITMAP_8_BY_13)
{
    glRasterPos3d(x, y, 0);
    int i;
    for (i=0; str[i]; i++) {
        glutBitmapCharacter(font, str[i]); //,GLUT_BITMAP_8_BY_13, GLUT_BITMAP_TIMES_ROMAN_24
    }
}

void iPoint(double x, double y, int size=0)
{
    int i, j;
    glBegin(GL_POINTS);
    glVertex2f(x, y);
    for(i=x-size;i<x+size;i++)
    {
        for(j=y-size; j<y+size;j++)
        {
            glVertex2f(i, j);
        }
    }
    glEnd();
}

void iLine(double x1, double y1, double x2, double y2)
{
    glBegin(GL_LINE_STRIP);
    glVertex2f(x1, y1);
    glVertex2f(x2, y2);
    glEnd();
}

void iFilledPolygon(double x[], double y[], int n)
{
    int i;
    if(n<3)return;
    glBegin(GL_POLYGON);
    for(i = 0; i < n; i++){
        glVertex2f(x[i], y[i]);
    }
    glEnd();
}

void iPolygon(double x[], double y[], int n)
{
    int i;
    if(n<3)return;
    glBegin(GL_LINE_STRIP);
    for(i = 0; i < n; i++){
        glVertex2f(x[i], y[i]);
    }
    glVertex2f(x[0], y[0]);
    glEnd();
}

void iRectangle(double left, double bottom, double dx, double dy)
{
    double x1, y1, x2, y2;

    x1 = left;
    y1 = bottom;
    x2=x1+dx;
    y2=y1+dy;

    iLine(x1, y1, x2, y1);
    iLine(x2, y1, x2, y2);
    iLine(x2, y2, x1, y2);
    iLine(x1, y2, x1, y1);
}

void iFilledRectangle(double left, double bottom, double dx, double dy)
{
    double xx[4], yy[4];
    double x1, y1, x2, y2;

    x1 = left;
    y1 = bottom;
    x2=x1+dx;
    y2=y1+dy;

    xx[0]=x1;
    yy[0]=y1;
    xx[1]=x2;
    yy[1]=y1;
    xx[2]=x2;
    yy[2]=y2;
    xx[3]=x1;
    yy[3]=y2;

    iFilledPolygon(xx, yy, 4);
}

void iFilledCircle(double x, double y, double r, int slices=100)
{
    double t, PI=acos(-1.0), dt, x1,y1, xp, yp;
    dt = 2*PI/slices;
    xp = x+r;
    yp = y;
    glBegin(GL_POLYGON);
    for(t = 0; t <= 2*PI; t+=dt)
    {
        x1 = x + r * cos(t);
        y1 = y + r * sin(t);

        glVertex2f(xp, yp);
        xp = x1;
        yp = y1;
    }
    glEnd();
}

void iCircle(double x, double y, double r, int slices=100)
{
    double t, PI=acos(-1.0), dt, x1,y1, xp, yp;
    dt = 2*PI/slices;
    xp = x+r;
    yp = y;
    for(t = 0; t <= 2*PI; t+=dt)
    {
        x1 = x + r * cos(t);
        y1 = y + r * sin(t);
        iLine(xp, yp, x1, y1);
        xp = x1;
        yp = y1;
    }
}

void iEllipse(double x, double y, double a, double b, int slices=100)
{
    double t, PI=acos(-1.0), dt, x1,y1, xp, yp;
    dt = 2*PI/slices;
    xp = x+a;
    yp = y;
    for(t = 0; t <= 2*PI; t+=dt)
    {
        x1 = x + a * cos(t);
        y1 = y + b * sin(t);
        iLine(xp, yp, x1, y1);
        xp = x1;
        yp = y1;
    }
}

void iFilledEllipse(double x, double y, double a, double b, int slices=100)
{
    double t, PI=acos(-1.0), dt, x1,y1, xp, yp;
    dt = 2*PI/slices;
    xp = x+a;
    yp = y;
    glBegin(GL_POLYGON);
    for(t = 0; t <= 2*PI; t+=dt)
    {
        x1 = x + a * cos(t);
        y1 = y + b * sin(t);
        glVertex2f(xp, yp);
        xp = x1;
        yp = y1;
    }
    glEnd();
}

// Rotates the co-ordinate system
// Parameters:
//  (x, y) - The pivot point for rotation
//  degree - degree of rotation
//
// After calling iRotate(), evrey subsequent rendering will
// happen in rotated fashion. To stop rotation of subsequent rendering,
// call iUnRotate(). Typical call pattern would be:
//      iRotate();
//      Render your objects, that you want rendered as rotated
//      iUnRotate();
//
void iRotate(double x, double y, double degree)
{
	glPushMatrix();

	glTranslatef(x, y, 0.0);

	glRotatef(degree, 0, 0, 1.0);

	glTranslatef(-x, -y, 0.0);
}

void iUnRotate()
{
	glPopMatrix();
}

void iSetColor(double r, double g, double b)
{
    double mmx;
    mmx = r;
    if(g > mmx)mmx = g;
    if(b > mmx)mmx = b;
    mmx = 255;
    if(mmx > 0){
        r /= mmx;
        g /= mmx;
        b /= mmx;
    }
    glColor3f(r, g, b);
}

void iDelay(int sec)
{
    int t1, t2;
    t1 = time(0);
    while(1){
        t2 = time(0);
        if(t2-t1>=sec)
            break;
    }
}

void iDelayMS(int msec)
{
	clock_t end;
	end = clock() + msec * CLOCKS_PER_SEC / 1000;
	while (end > clock());
}

void iClear()
{
    glClear(GL_COLOR_BUFFER_BIT) ;
    glMatrixMode(GL_MODELVIEW) ;
    glClearColor(0,0,0,0);
    glFlush();
}

void displayFF(void){

    iDraw();
    glutSwapBuffers() ;
}

void animFF(void)
{
    if(ifft == 0){
        ifft = 1;
        iClear();
    }
    glutPostRedisplay();
}

void keyboardHandler1FF(unsigned char key, int x, int y)
{
    iKeyboard(key);
    glutPostRedisplay();
}
void keyboardHandler2FF(int key, int x, int y)
{
    iSpecialKeyboard(key);
    glutPostRedisplay();
}

void mouseMoveHandlerFF(int mx, int my)
{
    iMouseX = mx;
    iMouseY = iScreenHeight - my;
    iMouseMove(iMouseX, iMouseY);

    glFlush();
}

void mousePassiveMoveHandlerFF(int mx, int my)
{
	iMouseX = mx;
	iMouseY = iScreenHeight - my;
	iPassiveMouseMove(iMouseX, iMouseY);

	glFlush();
}

void mouseHandlerFF(int button, int state, int x, int y)
{
    iMouseX = x;
    iMouseY = iScreenHeight - y;

    iMouse(button, state, iMouseX, iMouseY);

    glFlush();
}

void iInitialize(int width=500, int height=500, char *title="iGraphics")
{
    iScreenHeight = height;
    iScreenWidth = width;

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_ALPHA) ;
    glutInitWindowSize(width , height ) ;
    glutInitWindowPosition( 10 , 10 ) ;
    glutCreateWindow(title) ;
    glClearColor( 0.0 , 0.0 , 0.0 , 0.0 ) ;
    glMatrixMode( GL_PROJECTION) ;
    glLoadIdentity() ;
    glOrtho(0.0 , width , 0.0 , height , -1.0 , 1.0) ;
    //glOrtho(-100.0 , 100.0 , -100.0 , 100.0 , -1.0 , 1.0) ;
    //SetTimer(0, 0, 10, timer_proc);


}

void iStart()
{
    iClear();

    glutDisplayFunc(displayFF) ;
    glutKeyboardFunc(keyboardHandler1FF); //normal
    glutSpecialFunc(keyboardHandler2FF); //special keys
    glutMouseFunc(mouseHandlerFF);
    glutMotionFunc(mouseMoveHandlerFF);
	glutPassiveMotionFunc(mousePassiveMoveHandlerFF);
    glutIdleFunc(animFF) ;

    //
    // Setup Alpha channel testing.
    // If alpha value is greater than 0, then those
    // pixels will be rendered. Otherwise, they would not be rendered
    //
    glAlphaFunc(GL_GREATER,0.0f);
    glEnable(GL_ALPHA_TEST);

    glutMainLoop();
}