Using the data storage type defined on this page for raster graphics images, draw a line given 2 points with the Bresenham’s line algorithm.

void Line( const float x1, const float y1, const float x2, const float y2, const Color& color ) { // Bresenham's line algorithm const bool steep = (fabs(y2 - y1) > fabs(x2 - x1)); if(steep) { std::swap(x1, y1); std::swap(x2, y2); } if(x1 > x2) { std::swap(x1, x2); std::swap(y1, y2); } const float dx = x2 - x1; const float dy = fabs(y2 - y1); float error = dx / 2.0f; const int ystep = (y1 < y2) ? 1 : -1; int y = (int)y1; const int maxX = (int)x2; for(int x=(int)x1; x<maxX; x++) { if(steep) { SetPixel(y,x, color); } else { SetPixel(x,y, color); } error -= dy; if(error < 0) { y += ystep; error += dx; } } }

Content is available under GNU Free Documentation License 1.2.