public static void drawScissor(NvgContext vg, float x, float y, float t)
{
vg.Save();
// Draw first rect and set scissor to it's area.
vg.Translate(x, y);
vg.Rotate(NvgUtility.DegToRad(5));
vg.BeginPath();
vg.Rect(-20, -20, 60, 40);
vg.FillColor(new Color(255, 0, 0, 255));
vg.Fill();
vg.Scissor(-20, -20, 60, 40);
// Draw second rectangle with offset and rotation.
vg.Translate(40, 0);
vg.Rotate(t);
// Draw the intended second rectangle without any scissoring.
vg.Save();
vg.ResetScissor();
vg.BeginPath();
vg.Rect(-20, -10, 60, 30);
vg.FillColor(new Color(255, 128, 0, 64));
vg.Fill();
vg.Restore();
// Draw second rectangle with combined scissoring.
vg.IntersectScissor(-20, -10, 60, 30);
vg.BeginPath();
vg.Rect(-20, -10, 60, 30);
vg.FillColor(new Color(255, 128, 0, 255));
vg.Fill();
vg.Restore();
}
public static void drawColorwheel(NvgContext vg, float x, float y, float w, float h, float t)
{
int i;
float r0, r1, ax, ay, bx, by, cx, cy, aeps, r;
float hue = (float)Math.Sin(t * 0.12f);
Paint paint;
vg.Save();
/* vg.BeginPath();
* vg.Rect(x,y,w,h);
* vg.FillColor(new Color(255,0,0,128));
* vg.Fill();*/
cx = x + w * 0.5f;
cy = y + h * 0.5f;
r1 = (w < h ? w : h) * 0.5f - 5.0f;
r0 = r1 - 20.0f;
aeps = 0.5f / r1; // half a pixel arc length in radians (2pi cancels out).
for (i = 0; i < 6; i++)
{
float a0 = (float)i / 6.0f * (float)Math.PI * 2.0f - aeps;
float a1 = (float)(i + 1.0f) / 6.0f * (float)Math.PI * 2.0f + aeps;
vg.BeginPath();
vg.Arc(cx, cy, r0, a0, a1, Winding.ClockWise);
vg.Arc(cx, cy, r1, a1, a0, Winding.CounterClockWise);
vg.ClosePath();
ax = cx + (float)Math.Cos(a0) * (r0 + r1) * 0.5f;
ay = cy + (float)Math.Sin(a0) * (r0 + r1) * 0.5f;
bx = cx + (float)Math.Cos(a1) * (r0 + r1) * 0.5f;
by = cy + (float)Math.Sin(a1) * (r0 + r1) * 0.5f;
paint = vg.LinearGradient(ax, ay, bx, by, NvgUtility.HSLA(a0 / ((float)Math.PI * 2), 1.0f, 0.55f, 255), NvgUtility.HSLA(a1 / ((float)Math.PI * 2), 1.0f, 0.55f, 255));
vg.FillPaint(paint);
vg.Fill();
}
vg.BeginPath();
vg.Circle(cx, cy, r0 - 0.5f);
vg.Circle(cx, cy, r1 + 0.5f);
vg.StrokeColor(new Color(0, 0, 0, 64));
vg.StrokeWidth(1.0f);
vg.Stroke();
// Selector
vg.Save();
vg.Translate(cx, cy);
vg.Rotate(hue * (float)Math.PI * 2);
// Marker on
vg.StrokeWidth(2.0f);
vg.BeginPath();
vg.Rect(r0 - 1, -3, r1 - r0 + 2, 6);
vg.StrokeColor(new Color(255, 255, 255, 192));
vg.Stroke();
paint = vg.BoxGradient(r0 - 3, -5, r1 - r0 + 6, 10, 2, 4, new Color(0, 0, 0, 128), new Color(0, 0, 0, 0));
vg.BeginPath();
vg.Rect(r0 - 2 - 10, -4 - 10, r1 - r0 + 4 + 20, 8 + 20);
vg.Rect(r0 - 2, -4, r1 - r0 + 4, 8);
vg.PathWinding(Solidity.Hole);
vg.FillPaint(paint);
vg.Fill();
// Center triangle
r = r0 - 6;
ax = (float)Math.Cos(120.0f / 180.0f * (float)Math.PI) * r;
ay = (float)Math.Sin(120.0f / 180.0f * (float)Math.PI) * r;
bx = (float)Math.Cos(-120.0f / 180.0f * (float)Math.PI) * r;
by = (float)Math.Sin(-120.0f / 180.0f * (float)Math.PI) * r;
vg.BeginPath();
vg.MoveTo(r, 0);
vg.LineTo(ax, ay);
vg.LineTo(bx, by);
vg.ClosePath();
paint = vg.LinearGradient(r, 0, ax, ay, NvgUtility.HSLA(hue, 1.0f, 0.5f, 255), new Color(255, 255, 255, 255));
vg.FillPaint(paint);
vg.Fill();
paint = vg.LinearGradient((r + ax) * 0.5f, (0 + ay) * 0.5f, bx, by, new Color(0, 0, 0, 0), new Color(0, 0, 0, 255));
vg.FillPaint(paint);
vg.Fill();
vg.StrokeColor(new Color(0, 0, 0, 64));
vg.Stroke();
// Select circle on triangle
ax = (float)Math.Cos(120.0f / 180.0f * (float)Math.PI) * r * 0.3f;
ay = (float)Math.Sin(120.0f / 180.0f * (float)Math.PI) * r * 0.4f;
vg.StrokeWidth(2.0f);
vg.BeginPath();
vg.Circle(ax, ay, 5);
vg.StrokeColor(new Color(255, 255, 255, 192));
vg.Stroke();
paint = vg.RadialGradient(ax, ay, 7, 9, new Color(0, 0, 0, 64), new Color(0, 0, 0, 0));
vg.BeginPath();
vg.Rect(ax - 20, ay - 20, 40, 40);
vg.Circle(ax, ay, 7);
vg.PathWinding(Solidity.Hole);
vg.FillPaint(paint);
vg.Fill();
vg.Restore();
vg.Restore();
}