void HatchDiagonalCross(CGContext context)
{
var hatchWidth = getHatchWidth (hatchStyle);
var hatchHeight = getHatchHeight (hatchStyle);
var lineWidth = getLineWidth (hatchStyle);
initializeContext(context, hatchHeight, true);
/* draw background */
drawBackground (context, backColor, hatchWidth, hatchHeight);
/* draw lines in the foreground color */
context.SetStrokeColor(foreColor.ToCGColor());
context.SetLineWidth(lineWidth);
context.SetLineCap(CGLineCap.Square);
float halfMe = hatchHeight / 2.0f;
context.MoveTo(0, 0);
context.AddLineToPoint(hatchWidth, hatchHeight);
context.StrokePath();
context.MoveTo(hatchWidth, 0);
context.AddLineToPoint(0, hatchHeight);
context.StrokePath();
}
public static void DrawLine(CGContext context, List<PointF> points, CGColor color, float lineWidth, bool closePath, bool dashed)
{
if (points == null)
throw new NullReferenceException();
if (points.Count == 0)
throw new ArgumentException("The line must have at least one point.");
context.SaveState();
context.SetStrokeColor(color);
context.SetLineWidth(lineWidth);
context.MoveTo(points[0].X, points[0].Y);
for(int a = 1; a < points.Count; a++)
context.AddLineToPoint(points[a].X, points[a].Y);
if (dashed)
context.SetLineDash(0, new float[2] { 1, 2 }, 2);
if (closePath)
context.ClosePath();
context.StrokePath();
context.RestoreState();
}
void HatchDashedHorizontal(CGContext context)
{
var hatchWidth = getHatchWidth (hatchStyle);
var hatchHeight = getHatchHeight (hatchStyle);
var lineWidth = getLineWidth (hatchStyle);
initializeContext(context, hatchHeight, false);
/* draw background */
drawBackground (context, backColor, hatchWidth, hatchHeight);
/* draw lines in the foreground color */
context.SetStrokeColor(foreColor.ToCGColor());
context.SetLineWidth(lineWidth);
context.SetLineCap(CGLineCap.Square);
float halfMe = hatchHeight / 2.0f - 1;
hatchWidth -=1;
hatchHeight -= 1;
context.MoveTo(halfMe+1, halfMe);
context.AddLineToPoint(hatchWidth, halfMe);
context.StrokePath();
context.MoveTo(0,hatchHeight);
context.AddLineToPoint(halfMe, hatchHeight);
context.StrokePath();
}
void HatchDiagonalBrick(CGContext context)
{
var hatchWidth = getHatchWidth (hatchStyle);
var hatchHeight = getHatchHeight (hatchStyle);
var lineWidth = getLineWidth (hatchStyle);
initializeContext(context, hatchHeight, false);
/* draw background */
drawBackground (context, backColor, hatchWidth, hatchHeight);
/* draw lines in the foreground color */
context.SetStrokeColor(foreColor.ToCGColor());
context.SetLineWidth(lineWidth);
context.SetLineCap(CGLineCap.Square);
hatchHeight -= 1;
hatchWidth -= 1;
context.MoveTo(0, 0);
context.AddLineToPoint(hatchWidth,hatchHeight);
context.StrokePath();
context.MoveTo(0, hatchHeight);
context.AddLineToPoint(hatchWidth / 2.0f,hatchHeight / 2.0f);
context.StrokePath();
}
protected void HatchUpwardDiagonal(CGContext context)
{
var hatchSize = getHatchWidth (hatchStyle);
var lineWidth = getLineWidth (hatchStyle);
if (hatchStyle != HatchStyle.ForwardDiagonal &&
hatchStyle != HatchStyle.BackwardDiagonal)
{
initializeContext(context, hatchSize, false);
}
else {
initializeContext(context, hatchSize, true);
}
/* draw background */
drawBackground (context, backColor, hatchSize, hatchSize);
/* draw lines in the foreground color */
context.SetStrokeColor(foreColor.ToCGColor());
context.SetFillColor(foreColor.ToCGColor());
context.SetLineWidth(1);
context.SetLineCap(CGLineCap.Square);
context.MoveTo(0,0);
context.AddLineToPoint(hatchSize,hatchSize);
/* draw a diagonal line for as many times as linewidth*/
for (int l = 0; l < lineWidth; l++)
{
/* draw a diagonal line */
context.MoveTo(l,0);
context.AddLineToPoint(hatchSize, hatchSize-l);
context.StrokePath();
}
/**
* because we are within a rectangular pattern we have to complete the tip of the preceeding line
* pattern
*/
for (int k = 1; k < lineWidth; k++)
{
/* draw a diagonal line */
context.MoveTo(0,hatchSize-k);
context.AddLineToPoint(k-1, hatchSize-1);
context.StrokePath();
}
}
protected void HatchVertical(CGContext context)
{
var hatchSize = getHatchWidth (hatchStyle);
var lineWidth = getLineWidth (hatchStyle);
initializeContext(context, hatchSize, false);
/* draw background */
drawBackground (context, backColor, hatchSize, hatchSize);
/* draw horizontal line in the foreground color */
context.SetStrokeColor(foreColor.ToCGColor());
context.SetLineWidth(lineWidth);
context.SetLineCap(CGLineCap.Square);
float halfMe = hatchSize / 2.0f;
// draw a horizontal line
context.MoveTo(0, 0);
context.AddLineToPoint(0, hatchSize);
context.StrokePath();
}
void HatchWeave(CGContext context)
{
var hatchWidth = getHatchWidth (hatchStyle);
var hatchHeight = getHatchHeight (hatchStyle);
var lineWidth = getLineWidth (hatchStyle);
initializeContext(context, hatchHeight, false);
/* draw background */
drawBackground (context, backColor, hatchWidth, hatchHeight);
/* draw lines in the foreground color */
context.SetFillColor(foreColor.ToCGColor());
/* draw lines in the foreground color */
context.SetStrokeColor(foreColor.ToCGColor());
context.SetLineWidth(lineWidth);
context.SetLineCap(CGLineCap.Square);
float halfWidth = hatchWidth / 2.0f;
float halfHeight = hatchHeight / 2.0f;
RectangleF rect = new RectangleF(0,0,1,1);
// Add upward diagonals
context.MoveTo(0,0);
context.AddLineToPoint(halfWidth, halfHeight);
context.StrokePath();
context.MoveTo(0, halfHeight);
context.AddLineToPoint(halfWidth -1, hatchHeight - 1);
context.StrokePath();
context.MoveTo(halfWidth, 0);
context.AddLineToPoint(6, 2);
context.StrokePath();
// context.MoveTo(0, 4);
// context.AddLineToPoint(2, 2);
// context.StrokePath();
context.MoveTo(2,6);
context.AddLineToPoint(7, 1);
context.StrokePath();
}
protected void HatchGrid(CGContext context)
{
var hatchSize = getHatchWidth (hatchStyle);
var lineWidth = getLineWidth (hatchStyle);
initializeContext(context, hatchSize, false);
/* draw background */
drawBackground (context, backColor, hatchSize, hatchSize);
/* draw lines in the foreground color */
context.SetStrokeColor(foreColor.ToCGColor());
context.SetLineWidth(lineWidth);
context.SetLineCap(CGLineCap.Square);
hatchSize -=HALF_PIXEL_X;
float yoffset = 0;
if (hatchStyle == HatchStyle.DottedGrid)
{
yoffset = 1;
float[] dash = new float[] { 1, 1};
context.SetLineDash(2,dash);
}
/* draw a horizontal line */
context.MoveTo(0,yoffset);
context.AddLineToPoint(0,hatchSize);
context.StrokePath();
/* draw a vertical line */
context.MoveTo(0,hatchSize);
context.AddLineToPoint(hatchSize, hatchSize);
context.StrokePath();
}
void HatchSolidDiamond(CGContext context)
{
var hatchWidth = getHatchWidth (hatchStyle);
var hatchHeight = getHatchHeight (hatchStyle);
var lineWidth = getLineWidth (hatchStyle);
initializeContext(context, hatchHeight, false);
/* draw background */
drawBackground (context, backColor, hatchWidth, hatchHeight);
/* draw lines in the foreground color */
context.SetFillColor(foreColor.ToCGColor());
context.SetStrokeColor(foreColor.ToCGColor());
context.SetLineWidth(lineWidth);
context.SetLineCap(CGLineCap.Square);
float halfMe = hatchWidth / 2.0f;
// We will paint two triangles from corners meeting in the middle
// make sure to offset by half pixels so that the point is actually a point.
context.MoveTo(-HALF_PIXEL_X,HALF_PIXEL_Y);
context.AddLineToPoint(2+HALF_PIXEL_X, halfMe - HALF_PIXEL_Y);
context.AddLineToPoint(-HALF_PIXEL_X, hatchHeight- (1.0f + HALF_PIXEL_Y));
context.ClosePath();
context.FillPath();
// now we do the right one
context.MoveTo(hatchWidth,HALF_PIXEL_Y);
context.AddLineToPoint(halfMe+HALF_PIXEL_X, halfMe - HALF_PIXEL_Y);
context.AddLineToPoint(hatchWidth, hatchHeight - (1.0f + HALF_PIXEL_Y));
context.ClosePath();
context.FillPath();
}
void HatchShingle(CGContext context)
{
var hatchWidth = getHatchWidth (hatchStyle);
var hatchHeight = getHatchHeight (hatchStyle);
var lineWidth = getLineWidth (hatchStyle);
initializeContext(context, hatchHeight, false);
/* draw background */
drawBackground (context, backColor, hatchWidth, hatchHeight);
/* draw lines in the foreground color */
context.SetFillColor(foreColor.ToCGColor());
context.SetStrokeColor(foreColor.ToCGColor());
context.SetLineWidth(lineWidth);
context.SetLineCap(CGLineCap.Square);
float halfMe = hatchWidth / 2.0f;
// We are basically going to draw a lamda sign
// Draw base
context.MoveTo(0,0);
context.AddLineToPoint(halfMe,halfMe-HALF_PIXEL_Y);
context.AddLineToPoint(hatchWidth, HALF_PIXEL_Y);
context.StrokePath();
// draw the first part of tail
context.MoveTo(halfMe + HALF_PIXEL_X, halfMe);
context.AddLineToPoint(halfMe + HALF_PIXEL_X, halfMe + 1);
context.StrokePath();
// now the last curl on the tail
RectangleF rect = new RectangleF(1,hatchHeight-1,1,1);
setPixels(context, rect);
rect.X += 1;
setPixels(context, rect);
rect.X += 1;
rect.Y -= 1;
setPixels(context, rect);
}
void HatchOutlinedDiamond(CGContext context)
{
var hatchWidth = getHatchWidth (hatchStyle);
var hatchHeight = getHatchHeight (hatchStyle);
var lineWidth = getLineWidth (hatchStyle);
initializeContext(context, hatchHeight, false);
/* draw background */
drawBackground (context, backColor, hatchWidth, hatchHeight);
/* draw lines in the foreground color */
context.SetFillColor(foreColor.ToCGColor());
context.SetStrokeColor(foreColor.ToCGColor());
context.SetLineWidth(lineWidth);
context.SetLineCap(CGLineCap.Square);
// this is really just two diagonal lines from each corner too
// their opposite corners.
context.MoveTo(0,0);
context.AddLineToPoint(hatchWidth, hatchHeight);
context.StrokePath();
context.MoveTo(1,hatchHeight);
context.AddLineToPoint(hatchWidth, 1);
context.StrokePath();
}
void HatchHorizontalBrick(CGContext context)
{
var hatchWidth = getHatchWidth (hatchStyle);
var hatchHeight = getHatchHeight (hatchStyle);
var lineWidth = getLineWidth (hatchStyle);
initializeContext(context, hatchHeight, false);
/* draw background */
drawBackground (context, backColor, hatchWidth, hatchHeight);
/* draw lines in the foreground color */
context.SetFillColor(foreColor.ToCGColor());
/* draw lines in the foreground color */
context.SetStrokeColor(foreColor.ToCGColor());
context.SetLineWidth(lineWidth);
context.SetLineCap(CGLineCap.Square);
RectangleF rect = new RectangleF(0,0,1,1);
rect.Y = 3;
rect.Width = hatchWidth;
rect.Height = hatchHeight - 4;
context.StrokeRect(rect);
context.MoveTo(hatchWidth / 2.0f, 0);
context.AddLineToPoint(hatchWidth / 2.0f,3);
context.StrokePath();
}
/*
* Based on the algorithm described in
* http://www.stillhq.com/ctpfaq/2002/03/c1088.html#AEN1212
*/
static void make_arc(CGContext graphics, bool start, float x, float y, float width,
float height, float startAngle, float endAngle, bool antialiasing, bool isPieSlice)
{
float delta, bcp;
double sin_alpha, sin_beta, cos_alpha, cos_beta;
float PI = (float)Math.PI;
float rx = width / 2;
float ry = height / 2;
/* center */
float cx = x + rx;
float cy = y + ry;
/* angles in radians */
float alpha = startAngle * PI / 180;
float beta = endAngle * PI / 180;
/* adjust angles for ellipses */
alpha = (float)Math.Atan2(rx * Math.Sin(alpha), ry * Math.Cos(alpha));
beta = (float)Math.Atan2(rx * Math.Sin(beta), ry * Math.Cos(beta));
if (Math.Abs(beta - alpha) > PI)
{
if (beta > alpha)
beta -= 2 * PI;
else
alpha -= 2 * PI;
}
delta = beta - alpha;
bcp = (float)(4.0 / 3.0 * (1 - Math.Cos(delta / 2)) / Math.Sin(delta / 2));
sin_alpha = Math.Sin(alpha);
sin_beta = Math.Sin(beta);
cos_alpha = Math.Cos(alpha);
cos_beta = Math.Cos(beta);
/* don't move to starting point if we're continuing an existing curve */
if (start)
{
/* starting point */
double sx = cx + rx * cos_alpha;
double sy = cy + ry * sin_alpha;
if (isPieSlice)
graphics.AddLineToPoint((float)sx,(float)sy);
else
graphics.MoveTo((float)sx,(float)sy);
}
graphics.AddCurveToPoint(cx + rx * (float)(cos_alpha - bcp * sin_alpha),
cy + ry * (float)(sin_alpha + bcp * cos_alpha),
cx + rx * (float)(cos_beta + bcp * sin_beta),
cy + ry * (float)(sin_beta - bcp * cos_beta),
cx + rx * (float)cos_beta, cy + ry * (float)sin_beta);
}
