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copied!<p>A somewhat less "<a href="http://en.wikipedia.org/wiki/Na%C3%AFve_algorithm" rel="nofollow noreferrer">naïve</a>" approach would be to use a <a href="http://alienryderflex.com/polygon_fill/" rel="nofollow noreferrer">polygon fill algorithm</a>, and then select points from the fill lines randomly.</p> <h2>C Code Sample</h2> <pre><code>// public-domain code by Darel Rex Finley, 2007 int nodes, nodeX[MAX_POLY_CORNERS], pixelX, pixelY, i, j, swap ; // Loop through the rows of the image. for (pixelY=IMAGE_TOP; pixelY<IMAGE_BOT; pixelY++) { // Build a list of nodes. nodes=0; j=polyCorners-1; for (i=0; i<polyCorners; i++) { if (polyY[i]<(double) pixelY && polyY[j]>=(double) pixelY || polyY[j]<(double) pixelY && polyY[i]>=(double) pixelY) { nodeX[nodes++]=(int) (polyX[i]+(pixelY-polyY[i])/(polyY[j]-polyY[i]) *(polyX[j]-polyX[i])); } j=i; } // Sort the nodes, via a simple “Bubble” sort. i=0; while (i<nodes-1) { if (nodeX[i]>nodeX[i+1]) { swap=nodeX[i]; nodeX[i]=nodeX[i+1]; nodeX[i+1]=swap; if (i) i--; } else { i++; }} // Fill the pixels between node pairs. // Code modified by SoloBold 27 Oct 2008 // The flagPixel method below will flag a pixel as a possible choice. for (i=0; i<nodes; i+=2) { if (nodeX[i ]>=IMAGE_RIGHT) break; if (nodeX[i+1]> IMAGE_LEFT ) { if (nodeX[i ]< IMAGE_LEFT ) nodeX[i ]=IMAGE_LEFT ; if (nodeX[i+1]> IMAGE_RIGHT) nodeX[i+1]=IMAGE_RIGHT; for (j=nodeX[i]; j<nodeX[i+1]; j++) flagPixel(j,pixelY); }}} // TODO pick a flagged pixel randomly and fill it, then remove it from the list. // Repeat until no flagged pixels remain. </code></pre>

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