From a58172d7227da0b707cd32dc2f66e2964b7f51ca Mon Sep 17 00:00:00 2001
From: lecoanet
Date: Mon, 9 Dec 2002 14:34:07 +0000
Subject: 	* Reprise du code des gradients (incompatibilit�s). 	* Les
 lignes sont anti-alias�es m�me si elles ont de 	  l'alpha, jusqu'�
 80%, en dessous, il n'y en a pas besoin.

---
 generic/Draw.c | 193 +++++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 145 insertions(+), 48 deletions(-)

(limited to 'generic/Draw.c')

diff --git a/generic/Draw.c b/generic/Draw.c
index 7587082..6ddad6a 100644
--- a/generic/Draw.c
+++ b/generic/Draw.c
@@ -1023,7 +1023,7 @@ ZnRenderPolyline(WidgetInfo	*wi,
 {
   int		num_clips = ZnListSize(wi->clip_stack);
   ZnPoint	end_points[LINE_END_POINTS];
-  ZnBool	need_rcaps, thin, closed;
+  ZnBool	need_rcaps, thin, closed, transparent;
   int		pass, num_passes, i, k, m;
   ZnPoint	c1, c2;    
   XColor	*color;
@@ -1045,7 +1045,11 @@ ZnRenderPolyline(WidgetInfo	*wi,
   glColor4us(color->red, color->green, color->blue, alpha);
   ZnSetLineStyle(wi, line_style);
   glLineWidth(line_width);
-  if (thin && (alpha != 65535)) {
+  /*
+   * Do not use joints under this transparency value.
+   */
+  transparent = alpha < (65535 * 0.8);
+  if (thin && transparent) {
     /*
      * This makes a special case for transparent lines.
      * In this case we need to avoid drawing twice a
@@ -1064,16 +1068,16 @@ ZnRenderPolyline(WidgetInfo	*wi,
     glDisable(GL_LINE_SMOOTH);
   }
   else {
-    glPointSize(line_width);
+    glPointSize(line_width>1?line_width-1:line_width);
   }
 
   num_passes = 1;
-  if (alpha != 65535) {
+  if (transparent) {
     num_passes = 2;
   }
     
   for (pass = 0; pass < num_passes; pass++) {
-    if (alpha != 65535) {
+    if (transparent) {
       if (pass == 0) {
 	GLX_START_CLIP(num_clips, True);
       }
@@ -1363,42 +1367,134 @@ ZnComputeAxialGradient(WidgetInfo	*wi,
 void
 ZnComputeRadialGradient(WidgetInfo	*wi,
 			ZnPoly		*shape,
-			ZnBBox		*bbox,
-			ZnPoint		*center,
+			ZnBool		oval,
+			ZnPoint		*focal_pp, /* in percent of bbox */
 			ZnPoint		*grad_geo)
 {
-  ZnReal	dist, new, x, y, fact;
+  ZnReal	dist, new, x, y, ff;
+  ZnBBox	bbox;
   ZnContour	*c;
+  ZnPoint	offset, focal_point, radius;
   ZnPoint	*points;
-  ZnTransfo	*transfo1;
+  ZnTransfo	t1;
   int		i, j;
 
-  ZnTransformPoint(wi->current_transfo, center, &grad_geo[0]);
-  transfo1 = ZnTransfoNew();
-  ZnTranslate(transfo1, -grad_geo[0].x, -grad_geo[0].y);
-  fact = (bbox->corner.x-bbox->orig.x)/(bbox->corner.y-bbox->orig.y);
-  ZnScale(transfo1, 1.0, fact);
-  dist = 0.0;
+  /*
+   * Compute the shape bbox (which should be in the item space).
+   */
+  ResetBBox(&bbox);
   c = shape->contours;
+  dist = 0.0;
   for (j = 0; j < shape->num_contours; j++, c++) {
     if (c->cw) {
       continue;
     }
-    ZnListAssertSize(wi->work_pts, c->num_points);
-    points = ZnListArray(wi->work_pts);
-    ZnTransformPoints(transfo1, c->points, points, c->num_points);
-    for (i = 0; i < c->num_points; i++, points++) {
-      x = points->x;
-      y = points->y;
-      new = x*x+y*y;
-      if (new > dist) {
-	dist = new;
+    AddPointsToBBox(&bbox, c->points, c->num_points); 
+  }
+
+  /*
+   * Find the gradient focal point in the item space.
+   */
+  offset.x = focal_pp->x * (bbox.corner.x-bbox.orig.x)/100.0;
+  offset.y = focal_pp->y * (bbox.corner.y-bbox.orig.y)/100.0;
+  focal_point.x = (bbox.corner.x+bbox.orig.x)/2 + offset.x; 
+  focal_point.y = (bbox.corner.y+bbox.orig.y)/2 + offset.y; 
+
+  /*
+   * Find the max distance from the focal point.
+   */
+  if (oval) {
+    /*
+     * radius.x and radius.y are the shape radiuses.
+     * ff is the distance from the bbox center to
+     * the focal point.
+     */
+    radius.x = (bbox.corner.x-bbox.orig.x)/2;
+    radius.y = (bbox.corner.y-bbox.orig.y)/2;
+    ff = sqrt(offset.x*offset.x + offset.y*offset.y);
+    /*
+     * Compute the farthest point from the focal point 
+     * on a unit circle, then map it to the oval and
+     * compute the distance between both points.
+     */
+    x = offset.x/ff;
+    y = offset.y/ff;
+    x *= radius.x;
+    y *= radius.y;
+    x = x + offset.x;
+    y = y + offset.y;
+    dist = x*x + y*y;
+  }
+  else {
+    /*
+     * Use the given shape
+     */
+    c = shape->contours;
+    for (j = 0; j < shape->num_contours; j++, c++) {
+      if (c->cw) {
+	continue;
+      }
+      for (i = 0, points = c->points; i < c->num_points; i++, points++) {
+	x = points->x - focal_point.x;
+	y = points->y - focal_point.y;
+	new = x*x+y*y;
+	if (new > dist) {
+	  dist = new;
+	}
       }
     }
   }
-  grad_geo[1].x = sqrt(dist) + 2; /* Max radius plus a fuzz factor */
-  grad_geo[1].y = grad_geo[1].x / fact;
-  ZnTransfoFree(transfo1);
+
+  /*
+   * Create a transform to map a unit circle to another one that fill
+   * the item when located at the focal point.
+   */
+  dist = sqrt(dist); /* Max radius plus a fuzz factor */
+  ZnTransfoSetIdentity(&t1);
+  ZnScale(&t1, dist, dist);
+
+  /*
+   * Then, center the oval on the focal point.
+   */
+  ZnTranslate(&t1, focal_point.x, focal_point.y);
+  /*
+   * Last, compose with the current transform.
+   */
+  ZnTransfoCompose((ZnTransfo *) grad_geo, &t1, wi->current_transfo);
+}
+
+void
+ZnComputePathGradient(WidgetInfo	*wi,
+		      ZnPoly		*shape,
+		      ZnPoint		*focal_pp, /* in percent of the bbox */
+		      ZnPoint		*grad_geo)
+{
+  ZnBBox	bbox;
+  ZnContour	*c;
+  ZnPoint	focal_point;
+  int		j;
+
+  /*
+   * Compute the shape bbox (which should be in the item space).
+   */
+  ResetBBox(&bbox);
+  c = shape->contours;
+  for (j = 0; j < shape->num_contours; j++, c++) {
+    if (c->cw) {
+      continue;
+    }
+    AddPointsToBBox(&bbox, c->points, c->num_points); 
+  }
+
+  /*
+   * Find the gradient center in the item space.
+   */
+  focal_point.x = (bbox.corner.x+bbox.orig.x)/2 + focal_pp->x * (bbox.corner.x-bbox.orig.x)/100.0;
+  focal_point.y = (bbox.corner.y+bbox.orig.y)/2 + focal_pp->y * (bbox.corner.y-bbox.orig.y)/100.0;
+  /*
+   * Then convert it to device space.
+   */
+  ZnTransformPoint(wi->current_transfo, &focal_point, &grad_geo[0]);
 }
 
 void
@@ -1518,39 +1614,41 @@ ZnRenderGradient(WidgetInfo	*wi,
     glEnd();
   }
   else if (type == ZN_RADIAL_GRADIENT) {
-    ZnReal	x, radiusx, radius2x, radius3x;
-    ZnReal	y, radiusy, radius2y, radius3y;
+    ZnReal	x, position, position2, position3;
+    ZnReal	y;
     int		num_p, alpha2;
-    ZnPoint	*genarc;
+    ZnPoint	*genarc, *tarc, p, focalp;
     XColor	*color2;
 
     genarc = GetCirclePoints(3, ZN_CIRCLE_FINE, 0, 2*M_PI, &num_p, NULL);
-    radiusx = 0;
-    radiusy = 0;
+    ZnListAssertSize(wi->work_pts, num_p);
+    tarc = ZnListArray(wi->work_pts);
+    ZnTransformPoints((ZnTransfo *) quad, genarc, tarc, num_p);
+    p.x = p.y = 0;
+    ZnTransformPoint((ZnTransfo *) quad, &p, &focalp);
+
+    position = 0.0;
     color = gradient->colors[0].rgb;
     alpha = ZnComposeAlpha(gradient->colors[0].alpha, wi->alpha);
     control = gradient->colors[0].control;
     for (j = 1; j < gradient->num_colors; j++) {
-      radius2x = quad[1].x*gradient->colors[j].position/100.0;
-      radius2y = quad[1].y*gradient->colors[j].position/100.0;
+      position2 = gradient->colors[j].position/100.0;
       if ((control != 50) && (j != gradient->num_colors-1)) {
 	glBegin(GL_QUAD_STRIP);
 	color2 = gradient->colors[j-1].mid_rgb;
 	alpha2 = ZnComposeAlpha(gradient->colors[j-1].mid_alpha, wi->alpha);
-	radius3x = radiusx + (radius2x-radiusx)*control/100.0;
-	radius3y = radiusy + (radius2y-radiusy)*control/100.0;
+	position3 = position + (position2-position)*control/100.0;
 	for (i = 0; i < num_p; i++) {
-	  x = quad[0].x+genarc[i].x*radiusx;
-	  y = quad[0].y+genarc[i].y*radiusy;
+	  x = focalp.x + (tarc[i].x-focalp.x) * position;
+	  y = focalp.y + (tarc[i].y-focalp.y) * position;
 	  glColor4us(color->red, color->green, color->blue, alpha);
 	  glVertex2f(x, y);
-	  x = quad[0].x+genarc[i].x*radius3x;
-	  y = quad[0].y+genarc[i].y*radius3y;
+	  x = focalp.x + (tarc[i].x-focalp.x) * position3;
+	  y = focalp.y + (tarc[i].y-focalp.y) * position3;
 	  glColor4us(color2->red, color2->green, color2->blue, alpha);
 	  glVertex2f(x, y);
 	}
-	radiusx = radius3x;
-	radiusy = radius3y;
+	position = position3;
 	color = color2;
 	alpha = alpha2;
 	glEnd();
@@ -1559,18 +1657,17 @@ ZnRenderGradient(WidgetInfo	*wi,
       color2 = gradient->colors[j].rgb;
       alpha2 = ZnComposeAlpha(gradient->colors[j].alpha, wi->alpha);
       for (i = 0; i < num_p; i++) {
-	x = quad[0].x+genarc[i].x*radiusx;
-	y = quad[0].y+genarc[i].y*radiusy;
+	x = focalp.x + (tarc[i].x-focalp.x) * position;
+	y = focalp.y + (tarc[i].y-focalp.y) * position;
 	glColor4us(color->red, color->green, color->blue, alpha);
 	glVertex2f(x, y);
-	x = quad[0].x+genarc[i].x*radius2x;
-	y = quad[0].y+genarc[i].y*radius2y;
+	x = focalp.x + (tarc[i].x-focalp.x) * position2;
+	y = focalp.y + (tarc[i].y-focalp.y) * position2;
 	glColor4us(color2->red, color2->green, color2->blue, alpha2);
 	glVertex2f(x, y);
       }
       glEnd();
-      radiusx = radius2x;
-      radiusy = radius2y;
+      position = position2;
       color = color2;
       alpha = alpha2;
       control = gradient->colors[j].control;
-- 
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