From 70349a403da6be8dc7c212bcf1ac2676eaddb1cc Mon Sep 17 00:00:00 2001
From: Pietro Gagliardi <pietro10@mac.com>
Date: Wed, 7 Oct 2015 18:32:55 -0400
Subject: [PATCH] Implemented radial gradients.

---
 winarea_d2d/draw.c | 31 ++++++++++++++++++++++++----
 winarea_d2d/main.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++
 winarea_d2d/ui.h   |  4 ++--
 3 files changed, 79 insertions(+), 6 deletions(-)

diff --git a/winarea_d2d/draw.c b/winarea_d2d/draw.c
index e09e7e74..293ad5ca 100644
--- a/winarea_d2d/draw.c
+++ b/winarea_d2d/draw.c
@@ -348,11 +348,34 @@ static ID2D1Brush *makeLinearBrush(uiDrawBrush *b, ID2D1RenderTarget *rt, D2D1_B
 	return (ID2D1Brush *) brush;
 }
 
-/* TODO
 static ID2D1Brush *makeRadialBrush(uiDrawBrush *b, ID2D1RenderTarget *rt, D2D1_BRUSH_PROPERTIES *props)
 {
+	ID2D1RadialGradientBrush *brush;
+	D2D1_RADIAL_GRADIENT_BRUSH_PROPERTIES gprops;
+	ID2D1GradientStopCollection *stops;
+	HRESULT hr;
+
+	ZeroMemory(&gprops, sizeof (D2D1_RADIAL_GRADIENT_BRUSH_PROPERTIES));
+	gprops.gradientOriginOffset.x = b->X0 - b->X1;
+	gprops.gradientOriginOffset.y = b->Y0 - b->Y1;
+	gprops.center.x = b->X1;
+	gprops.center.y = b->Y1;
+	gprops.radiusX = b->OuterRadius;
+	gprops.radiusY = b->OuterRadius;
+
+	stops = mkstops(b, rt);
+
+	hr = ID2D1RenderTarget_CreateRadialGradientBrush(rt,
+		&gprops,
+		props,
+		stops,
+		&brush);
+	if (hr != S_OK)
+		logHRESULT("error creating gradient brush in makeRadialBrush()", hr);
+
+	ID2D1GradientStopCollection_Release(stops);
+	return (ID2D1Brush *) brush;
 }
-*/
 
 static ID2D1Brush *makeBrush(uiDrawBrush *b, ID2D1RenderTarget *rt)
 {
@@ -369,8 +392,8 @@ static ID2D1Brush *makeBrush(uiDrawBrush *b, ID2D1RenderTarget *rt)
 		return makeSolidBrush(b, rt, &props);
 	case uiDrawBrushTypeLinearGradient:
 		return makeLinearBrush(b, rt, &props);
-//	case uiDrawBrushTypeRadialGradient:
-//		return makeRadialBrush(b, rt, &props);
+	case uiDrawBrushTypeRadialGradient:
+		return makeRadialBrush(b, rt, &props);
 //	case uiDrawBrushTypeImage:
 //		TODO
 	}
diff --git a/winarea_d2d/main.c b/winarea_d2d/main.c
index e256a35c..d7764c5a 100644
--- a/winarea_d2d/main.c
+++ b/winarea_d2d/main.c
@@ -176,6 +176,56 @@ static void handlerDraw(uiAreaHandler *a, uiArea *area, uiAreaDrawParams *p)
 	}
 #undef YO
 #undef XO
+	uiDrawFreePath(path);
+
+	// based on https://msdn.microsoft.com/en-us/library/windows/desktop/dd756679%28v=vs.85%29.aspx
+	path = uiDrawNewPath(uiDrawFillModeWinding);
+	uiDrawPathNewFigure(path, 585, 235);
+	uiDrawPathArcTo(path,
+		510, 235,
+		75,
+		0,
+		// TODO why doesn't 360° work
+		2 * M_PI - 0.1);
+	uiDrawPathEnd(path);
+	// first the stroke
+	brush.Type = uiDrawBrushTypeSolid;
+	brush.R = 0;
+	brush.G = 0;
+	brush.B = 0;
+	brush.A = 1;
+	sp.Cap = uiDrawLineCapFlat;
+	sp.Join = uiDrawLineJoinMiter;
+	sp.MiterLimit = uiDrawDefaultMiterLimit;
+	sp.Thickness = 1;
+	uiDrawStroke(p->Context, path, &brush, &sp);
+	// then the fill
+	{
+		uiDrawBrushGradientStop stops[2];
+
+		stops[0].Pos = 0.0;
+		stops[0].R = 1.0;
+		stops[0].G = 1.0;
+		stops[0].B = 0.0;
+		stops[0].A = 1.0;
+		stops[1].Pos = 1.0;
+		stops[1].R = ((double) 0x22) / 255.0;
+		stops[1].G = ((double) 0x8B) / 255.0;
+		stops[1].B = ((double) 0x22) / 255.0;
+		stops[1].A = 1.0;
+		brush.Type = uiDrawBrushTypeRadialGradient;
+		// start point
+		brush.X0 = 510;
+		brush.Y0 = 235;
+		// outer circle's center
+		brush.X1 = 510;
+		brush.Y1 = 235;
+		brush.OuterRadius = 75;
+		brush.Stops = stops;
+		brush.NumStops = 2;
+		uiDrawFill(p->Context, path, &brush);
+	}
+	uiDrawFreePath(path);
 }
 
 static uintmax_t handlerHScrollMax(uiAreaHandler *a, uiArea *area)
diff --git a/winarea_d2d/ui.h b/winarea_d2d/ui.h
index 03698508..9eae3ff6 100644
--- a/winarea_d2d/ui.h
+++ b/winarea_d2d/ui.h
@@ -52,9 +52,9 @@ typedef enum uiDrawFillMode uiDrawFillMode;
 enum uiDrawBrushType {
 	uiDrawBrushTypeSolid,
 	uiDrawBrushTypeLinearGradient,
-/*TODO	uiDrawBrushTypeRadialGradient,
+	uiDrawBrushTypeRadialGradient,
 	uiDrawBrushTypeImage,
-*/};
+};
 
 enum uiDrawLineCap {
 	uiDrawLineCapFlat,