fix graph curve drawing

src/zlfo_ui.c

@@ -1012,108 +1012,14 @@ add_bot_buttons (
     self->app, (ZtkWidget *) control, 2);
 }
 
+/**
+ * Draws the graphs in curve mode.
+ */
 static void
-mid_region_bg_draw_cb (
-  ZtkWidget * widget,
-  cairo_t *   cr,
-  ZLfoUi *    self)
+draw_graph_curves (
+  ZLfoUi *  self,
+  cairo_t * cr)
 {
-  /* set background */
-  zlfo_ui_theme_set_cr_color (cr, selected_bg);
-  cairo_rectangle (
-    cr, widget->rect.x, widget->rect.y,
-    widget->rect.width, widget->rect.height);
-  cairo_fill (cr);
-
-  /* draw grid */
-  for (int i = 0; i < 9; i++)
-    {
-      if ((i % 4) == 0)
-        {
-          zlfo_ui_theme_set_cr_color (
-            cr, grid_strong);
-        }
-      else
-        {
-          zlfo_ui_theme_set_cr_color (
-            cr, grid);
-        }
-      cairo_move_to (
-        cr,
-        widget->rect.x + GRID_HPADDING +
-          i * GRID_SPACE,
-        widget->rect.y + GRID_YSTART_OFFSET);
-      cairo_line_to (
-        cr,
-        widget->rect.x + GRID_HPADDING +
-          i * GRID_SPACE,
-        widget->rect.y + GRID_YEND_OFFSET);
-      cairo_stroke (cr);
-    }
-  zlfo_ui_theme_set_cr_color (
-    cr, grid_strong);
-  cairo_move_to (
-    cr,
-    GRID_XSTART_GLOBAL,
-    widget->rect.y + 105);
-  cairo_line_to (
-    cr,
-    GRID_XEND_GLOBAL,
-    widget->rect.y + 105);
-  cairo_stroke (cr);
-
-/*#if 0*/
-  /* draw current position */
-  double total_space = GRID_WIDTH;
-  double current_offset =
-    (double) self->common.current_sample /
-    (double) self->common.period_size;
-#if 0
-  ztk_message (
-    "current_sample %ld, period size %ld",
-    self->current_sample, self->period_size);
-#endif
-  cairo_move_to (
-    cr,
-    widget->rect.x + GRID_HPADDING +
-      current_offset * total_space,
-    widget->rect.y + 46);
-  cairo_line_to (
-    cr,
-    widget->rect.x + GRID_HPADDING +
-      current_offset * total_space,
-    widget->rect.y + 164);
-  cairo_stroke (cr);
-/*#endif*/
-
-  float sync_rate_float =
-    sync_rate_to_float (
-      self->sync_rate,
-      self->sync_rate_type);
-
-  /**
-   * Effective frequency.
-   *
-   * This is either the free-running frequency,
-   * or the frequency corresponding to the current
-   * sync rate.
-   */
-  float effective_freq =
-    get_effective_freq (
-      self->freerun, self->freq,
-      &self->common.host_pos, sync_rate_float);
-
-  recalc_vars (
-    self->freerun,
-    &self->common.sine_multiplier,
-    &self->common.saw_multiplier,
-    &self->common.period_size,
-    &self->common.current_sample,
-    &self->common.host_pos, effective_freq,
-    sync_rate_float,
-    (float) self->common.samplerate);
-
-  /* draw other visible waves in the back */
   double max_range =
     MAX (self->range_max, self->range_min);
   double min_range =
@@ -1123,8 +1029,12 @@ mid_region_bg_draw_cb (
   cairo_set_source_rgba (
     cr, zlfo_ui_theme.line.red,
     zlfo_ui_theme.line.green,
-    zlfo_ui_theme.line.blue, 0.3);
-  cairo_set_line_width (cr, 3);
+    zlfo_ui_theme.line.blue, 1);
+  cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
+  cairo_set_line_width (cr, 6);
+  double prev_draw_sine,
+         prev_draw_triangle,
+         prev_draw_saw, prev_draw_square;
   for (int i = 0; i < GRID_WIDTH; i++)
     {
       /* from 0 to GRID_WIDTH */
@@ -1191,18 +1101,22 @@ mid_region_bg_draw_cb (
    * in cairo */ \
   draw_val = GRID_HEIGHT - draw_val; \
  \
-  /* draw line */ \
-  cairo_move_to ( \
-    cr, \
-    widget->rect.x + GRID_HPADDING + i, \
-    widget->rect.y + GRID_YSTART_OFFSET + \
-      draw_val); \
-  cairo_line_to ( \
-    cr, \
-    widget->rect.x + GRID_HPADDING + i + 1, \
-    widget->rect.y + GRID_YSTART_OFFSET + \
-      draw_val + 1); \
-  cairo_stroke (cr)
+  if (i != 0) \
+    { \
+      /* draw line */ \
+      cairo_move_to ( \
+        cr, \
+        GRID_XSTART_GLOBAL + i - 1, \
+        GRID_YSTART_GLOBAL + \
+          prev_draw_##val); \
+      cairo_line_to ( \
+        cr, \
+        GRID_XSTART_GLOBAL + i, \
+        GRID_YSTART_GLOBAL + \
+          draw_val); \
+      cairo_stroke (cr); \
+    } \
+  prev_draw_##val = draw_val
 
       /* calculate sine */
       double sine =
@@ -1274,6 +1188,117 @@ mid_region_bg_draw_cb (
     }
 }
 
+static void
+mid_region_bg_draw_cb (
+  ZtkWidget * widget,
+  cairo_t *   cr,
+  ZLfoUi *    self)
+{
+  /* set background */
+  zlfo_ui_theme_set_cr_color (cr, selected_bg);
+  cairo_rectangle (
+    cr, widget->rect.x, widget->rect.y,
+    widget->rect.width, widget->rect.height);
+  cairo_fill (cr);
+
+  /* draw grid */
+  for (int i = 0; i < 9; i++)
+    {
+      if ((i % 4) == 0)
+        {
+          zlfo_ui_theme_set_cr_color (
+            cr, grid_strong);
+        }
+      else
+        {
+          zlfo_ui_theme_set_cr_color (
+            cr, grid);
+        }
+      cairo_move_to (
+        cr,
+        widget->rect.x + GRID_HPADDING +
+          i * GRID_SPACE,
+        widget->rect.y + GRID_YSTART_OFFSET);
+      cairo_line_to (
+        cr,
+        widget->rect.x + GRID_HPADDING +
+          i * GRID_SPACE,
+        widget->rect.y + GRID_YEND_OFFSET);
+      cairo_stroke (cr);
+    }
+  zlfo_ui_theme_set_cr_color (
+    cr, grid_strong);
+  cairo_move_to (
+    cr,
+    GRID_XSTART_GLOBAL,
+    widget->rect.y + 105);
+  cairo_line_to (
+    cr,
+    GRID_XEND_GLOBAL,
+    widget->rect.y + 105);
+  cairo_stroke (cr);
+
+/*#if 0*/
+  /* draw current position */
+  double total_space = GRID_WIDTH;
+  double current_offset =
+    (double) self->common.current_sample /
+    (double) self->common.period_size;
+#if 0
+  ztk_message (
+    "current_sample %ld, period size %ld",
+    self->current_sample, self->period_size);
+#endif
+  cairo_move_to (
+    cr,
+    widget->rect.x + GRID_HPADDING +
+      current_offset * total_space,
+    widget->rect.y + 46);
+  cairo_line_to (
+    cr,
+    widget->rect.x + GRID_HPADDING +
+      current_offset * total_space,
+    widget->rect.y + 164);
+  cairo_stroke (cr);
+/*#endif*/
+
+  float sync_rate_float =
+    sync_rate_to_float (
+      self->sync_rate,
+      self->sync_rate_type);
+
+  /**
+   * Effective frequency.
+   *
+   * This is either the free-running frequency,
+   * or the frequency corresponding to the current
+   * sync rate.
+   */
+  float effective_freq =
+    get_effective_freq (
+      self->freerun, self->freq,
+      &self->common.host_pos, sync_rate_float);
+
+  recalc_vars (
+    self->freerun,
+    &self->common.sine_multiplier,
+    &self->common.saw_multiplier,
+    &self->common.period_size,
+    &self->common.current_sample,
+    &self->common.host_pos, effective_freq,
+    sync_rate_float,
+    (float) self->common.samplerate);
+
+  /* draw other visible waves in the back */
+  if (self->step_mode)
+    {
+    }
+  else
+    {
+      draw_graph_curves (self, cr);
+    }
+}
+
 static void
 mid_region_bg_update_cb (
   ZtkWidget * w,
@@ -1875,13 +1900,13 @@ add_grid_controls (
         case GRID_BTN_HMIRROR:
           rect.x =
             start + padding + width + padding +
-            68;
+            69;
           rect.width = 40;
           break;
         case GRID_BTN_VMIRROR:
           rect.x =
             start + padding + width + padding +
-            110;
+            111;
           rect.width = 40;
           break;
         default: