Fix assorted drawing bugs in framed curve.

	- treat drawing area of boxes and curves similarly.

	- handle a redraw request between
	  the last sample and the last point.

diff --git a/libs/canvas/framed_curve.cc b/libs/canvas/framed_curve.cc
index 017d6528a0d3746ae008ef98b9c8b40fdfb33af2..c5b2d6de22c3b4d476c4d5ef5a547a01848c24b8 100644 (file)
--- a/libs/canvas/framed_curve.cc
+++ b/libs/canvas/framed_curve.cc
@@ -108,6 +108,32 @@ FramedCurve::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) c
         * with this.
         */
 
+       /* x-axis limits of the curve, in window space coordinates */
+
+       Duple w1 = item_to_window (Duple (_points.front().x, 0.0));
+       Duple w2 = item_to_window (Duple (_points.back().x, 0.0));
+
+       /* clamp actual draw to area bound by points, rather than our bounding box which is slightly different */
+
+       context->save ();
+       context->rectangle (draw.x0, draw.y0, draw.width(), draw.height());
+       context->clip ();
+
+       /* expand drawing area by several pixels on each side to avoid cairo stroking effects at the boundary.
+          they will still occur, but cairo's clipping will hide them.
+       */
+
+       draw = draw.expand (4.0);
+
+       /* now clip it to the actual points in the curve */
+
+       if (draw.x0 < w1.x) {
+               draw.x0 = w1.x;
+       }
+
+       if (draw.x1 >= w2.x) {
+               draw.x1 = w2.x;
+       }
 
        setup_outline_context (context);
 
@@ -120,9 +146,9 @@ FramedCurve::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) c
                window_space = item_to_window (*it);
                context->move_to (window_space.x, window_space.y);
                ++it;
-               window_space = item_to_window (*it);
+               window_space = item_to_window (*it, false);
                context->line_to (window_space.x, window_space.y);
-               window_space = item_to_window (_points.back());
+               window_space = item_to_window (_points.back(), false);
                context->line_to (window_space.x, window_space.y);
 
                switch (curve_fill) {
@@ -133,7 +159,7 @@ FramedCurve::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) c
                                context->stroke_preserve ();
                                window_space = item_to_window (Duple(_points.back().x, draw.height()));
                                context->line_to (window_space.x, window_space.y);
-                               window_space = item_to_window (Duple(_points.back().x, draw.height()));
+                               window_space = item_to_window (Duple(_points.front().x, draw.height()));
                                context->line_to (window_space.x, window_space.y);
                                context->close_path();
                                setup_fill_context(context);
@@ -150,62 +176,50 @@ FramedCurve::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) c
                                context->fill ();
                                break;
                }
+               context->restore ();
 
        } else {
 
                /* curve of at least 3 points */
 
-               /* x-axis limits of the curve, in window space coordinates */
-
-               Duple w1 = item_to_window (Duple (_points.front().x, 0.0));
-               Duple w2 = item_to_window (Duple (_points.back().x, 0.0));
-
-               /* clamp actual draw to area bound by points, rather than our bounding box which is slightly different */
-
-               context->save ();
-               context->rectangle (draw.x0, draw.y0, draw.width(), draw.height());
-               context->clip ();
-
-               /* expand drawing area by several pixels on each side to avoid cairo stroking effects at the boundary.
-                  they will still occur, but cairo's clipping will hide them.
-                */
-
-               draw = draw.expand (4.0);
-
-               /* now clip it to the actual points in the curve */
-
-               if (draw.x0 < w1.x) {
-                       draw.x0 = w1.x;
-               }
-
-               if (draw.x1 >= w2.x) {
-                       draw.x1 = w2.x;
-               }
-
                /* find left and right-most sample */
                Duple window_space;
                Points::size_type left = 0;
-               Points::size_type right = n_samples;
+               Points::size_type right = n_samples - 1;
 
                for (Points::size_type idx = 0; idx < n_samples - 1; ++idx) {
                        window_space = item_to_window (Duple (samples[idx].x, 0.0));
-                       if (window_space.x >= draw.x0) break;
+                       if (window_space.x >= draw.x0) {
+                               break;
+                       }
                        left = idx;
                }
 
-               for (Points::size_type idx = n_samples - 1; idx > left + 1; --idx) {
+               for (Points::size_type idx = left; idx < n_samples - 1; ++idx) {
                        window_space = item_to_window (Duple (samples[idx].x, 0.0));
-                       if (window_space.x <= draw.x1) break;
-                       right = idx;
+                       if (window_space.x > draw.x1) {
+                               right = idx;
+                               break;
+                       }
+               }
+
+               /* a redraw may have been requested between the last sample and the last point.*/
+
+               Duple last_point = Duple (samples[right].x, samples[right].y);
+               Duple first_point = Duple (samples[left].x, samples[left].y);
+
+               if (draw.x1 > last_point.x) {
+                       last_point = Duple (_points.back().x, _points.back().y);
+               }
+               if (draw.x0 < first_point.x) {
+                       first_point = Duple (_points.front().x, _points.front().y);
                }
 
-               window_space = item_to_window (*_points.begin());
+               window_space = item_to_window (first_point);
                context->move_to (window_space.x, window_space.y);
-               /* draw line between samples */
-               window_space = item_to_window (Duple (samples[left].x, samples[left].y));
-               context->line_to (window_space.x, window_space.y);
 
-               for (uint32_t idx = left; idx < right; ++idx) {
+               /* draw line between samples */
+               for (uint32_t idx = left + 1; idx <= right; ++idx) {
                        window_space = item_to_window (Duple (samples[idx].x, samples[idx].y), false);
                        context->line_to (window_space.x, window_space.y);
                }
@@ -216,19 +230,21 @@ FramedCurve::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) c
                                break;
                        case Inside:
                                context->stroke_preserve ();
-                               window_space = item_to_window (Duple (samples[right-1].x, draw.height()));
+
+                               window_space = item_to_window (Duple (last_point.x, draw.height()));
                                context->line_to (window_space.x, window_space.y);
-                               window_space = item_to_window (Duple (samples[left].x, draw.height()));
+                               window_space = item_to_window (Duple (first_point.x, draw.height()));
                                context->line_to (window_space.x, window_space.y);
+
                                context->close_path();
                                setup_fill_context(context);
                                context->fill ();
                                break;
                        case Outside:
                                context->stroke_preserve ();
-                               window_space = item_to_window (Duple (samples[right-1].x, 0.0));
+                               window_space = item_to_window (last_point);
                                context->line_to (window_space.x, window_space.y);
-                               window_space = item_to_window (Duple (samples[left].x, 0.0));
+                               window_space = item_to_window (first_point);
                                context->line_to (window_space.x, window_space.y);
                                context->close_path();
                                setup_fill_context(context);