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POSegmentation Fault on OpenGL program
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copied!<p>I'm trying to draw the <a href="http://en.wikipedia.org/wiki/Sierpinski_carpet" rel="nofollow">Sierpinski carpet plane fractal</a> using OpenGL, but my program keeps receiving a SegFault error.</p> <p>My code is as follows: </p> <pre><code>#include <GL/gl.h> #include <GL/glut.h> #include <stdlib.h> #include <math.h> class GLintPoint { public: GLint x, y; }; int random(int m) { return rand() % m; } void drawDot(GLint x, GLint y) { glBegin(GL_POINTS); glVertex2i(x, y); glEnd(); } void init() { glClearColor(1.0, 1.0, 1.0, 0.0); glColor3f(0.0, 0.0, 0.0); glMatrixMode(GL_PROJECTION); glLoadIdentity(); gluOrtho2D(0.0, 640.0, 0.0, 480.0); } int isSierpinskiCarpetPixelFilled(int x, int y, int width, int height) { GLintPoint point; // base case 1 of 2 if ((x <= 0)||(y <= 0)||(x>=width)||(y>=height)) //top row or left column or out of bounds should be full { point.x = x; point.y = y; drawDot(point.x, point.y); } { /* If the grid was split in 9 parts, what part(x2,y2) would x,y fit into? */ int x2 = x * 3 / width; // an integer from 0..2 inclusive int y2 = y * 3 / height; // an integer from 0..2 inclusive // base case 2 of 2 if (x2 == 1 && y2 == 1) // if in the center square, it should be empty return 0; // general case /* offset x and y so it becomes bounded by 0..width/3 and 0..height/3 and prepares for recursive call some offset is added to make sure the parts have all the correct size when width and height isn't divisible by 3 */ x -= (x2 * width+2) / 3; y -= (y2 * height+2) / 3; width = (width +2-x2)/3; height = (height+2-y2)/3; } return isSierpinskiCarpetPixelFilled(x, y, width, height); } void drawSierpinskiCarpet() { glClear(GL_COLOR_BUFFER_BIT); glColor3f(0.0, 1.0, 0.0); int x = 50; int y = 50; isSierpinskiCarpetPixelFilled(x,y,50,50); glFlush(); } int main(int argc, char *argv[]) { glutInit(&argc, argv); glutInitWindowSize(640,480); glutInitWindowPosition(10,10); glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE); glutCreateWindow("The Sierpinski Carpet"); glutDisplayFunc(drawSierpinskiCarpet); init(); glutMainLoop(); return EXIT_SUCCESS; } </code></pre>

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