int lastXDrawn = -1;
Graphics2D lineGraphics = context.getGraphic2DForColor(exomeBorderColor);
do {
ExomeReferenceFrame.Gene gene = genes.get(idx);
double exomeStart = exomeFrame.genomeToExomePosition(gene.getStart());
double exomeEnd = exomeFrame.genomeToExomePosition(gene.getEnd());
pStart = (int) ((exomeStart - exomeOrigin) / frame.getScale()) + visibleBlockCount * blockGap;
pEnd = (int) ((exomeEnd - exomeOrigin) / frame.getScale()) + visibleBlockCount * blockGap;
if (pStart != lastXDrawn) {
lineGraphics.drawLine(pStart, top, pStart, top + visibleRect.height);