/* Line function
 *
 * Revised line function that will draw full lines
 * in any slope at any angle.
 */
void Line(int X1, int Y1, int X2, int Y2, unsigned char C)
{
    float currX, currY;           /* Current pixel to be plotted */
    float deltaX, deltaY, slope;  /* 2 deltas and slope */
    int tempVal;                  /* Holds temporary values */

    deltaX = X2 - X1;             /* Get value for delta X */
    deltaY = Y2 - Y1;             /* Get value for delta Y */

    if (deltaX < 0) deltaX = -deltaX;  /* Need absolute */
    if (deltaY < 0) deltaY = -deltaY;  /* values only.  */

    if (deltaY > deltaX) {

        /* |slope| > 1 */
        if (Y2 < Y1) {
            /* Swap coordinates, Y1 must be < Y2 */
            tempVal = Y2; Y2 = Y1; Y1 = tempVal;
            tempVal = X2; X2 = X1; X1 = tempVal;
        }

        /* Compute deltas and slope */
        deltaX = X2 - X1;
        deltaY = Y2 - Y1;

        /* Slope off the vertical axis */
        slope = deltaX / deltaY;

        /* Plot each pixel starting at (X1, Y1) */
        currX = X1;
        for (currY = Y1; currY <= Y2; currY++) {
            SetPixel((int)currX, (int)currY, C);
            currX += slope;    /* increment X by the slope */
        }
        return;

    } else if ((deltaY || deltaX) != 0) {

        /* |slope| < 1 */
        if (X2 < X1) {
            /* Swap coordinates, X1 must be < X2 */
            tempVal = X2; X2 = X1; X1 = tempVal;
            tempVal = Y2; Y2 = Y1; Y1 = tempVal;
        }

        /* Compute deltas and slope */
        deltaX = X2 - X1;
        deltaY = Y2 - Y1;

        /* Slope off the horizontal axis */
        slope = deltaY / deltaX;

        /* Plot each pixel starting at (X1, Y1) */
        currY = Y1;
        for (currX = X1; currX <= X2; currX++) {
            SetPixel((int)currX, (int)currY, C);
            currY += slope;    /* increment Y by the slope */
        }
        return;

    } else

        /* Set a single pixel because Y1 = Y2 and X1 = X2 */
        SetPixel(X1, Y1, C);
}