UI: Add Free Handle Types to CurveProfile Widget

Under the hood the CurveProfile widget (used for bevel custom profiles)
uses a bezier curve, but right now though it only supports two of the
bezier curve handle types, vector and auto. This patch adds support for
free handles and adds all of the logic for editing them.

This is the first step to the ability to import and export curve objects
in the widget.

There's some code cleanup in curveprofile.c. Movement for handles and
control points is abstracted to functions there rather than happening
in interface_handlers.c.

An "Apply Preset" button is also added, which solves a confusing issue
where you apply a preset, then change the number of samples and the
preset doesn't change. The button makes it clear that the preset needs
to be reapplied.

Reviewed By: Severin

Differential Revision: https://developer.blender.org/D6470

1 files changed, 90 insertions, 23 deletions

diff --git a/source/blender/editors/interface/interface_draw.c b/source/blender/editors/interface/interface_draw.c
index 1cb8565b38d..98cb85061f2 100644
--- a/source/blender/editors/interface/interface_draw.c
+++ b/source/blender/editors/interface/interface_draw.c
@@ -25,6 +25,7 @@
 #include <string.h>
 
 #include "DNA_color_types.h"
+#include "DNA_curve_types.h"
 #include "DNA_curveprofile_types.h"
 #include "DNA_movieclip_types.h"
 #include "DNA_screen_types.h"
@@ -2159,7 +2160,19 @@ void ui_draw_but_CURVE(ARegion *region, uiBut *but, const uiWidgetColors *wcol,
   immUnbindProgram();
 }
 
-/** Used to draw a curve profile widget. Somewhat similar to ui_draw_but_CURVE */
+/**
+ * Helper for #ui_draw_but_CURVEPROFILE. Used to tell whether to draw a control point's handles.
+ */
+static bool point_draw_handles(CurveProfilePoint *point)
+{
+  return (point->flag & PROF_SELECT &&
+          (ELEM(point->h1, HD_FREE, HD_ALIGN) || ELEM(point->h2, HD_FREE, HD_ALIGN))) ||
+         ELEM(point->flag, PROF_H1_SELECT, PROF_H2_SELECT);
+}
+
+/**
+ *  Draws the curve profile widget. Somewhat similar to ui_draw_but_CURVE.
+ */
 void ui_draw_but_CURVEPROFILE(ARegion *region,
                               uiBut *but,
                               const uiWidgetColors *wcol,
@@ -2175,18 +2188,18 @@ void ui_draw_but_CURVEPROFILE(ARegion *region,
     profile = (CurveProfile *)but->poin;
   }
 
-  /* Calculate offset and zoom */
+  /* Calculate offset and zoom. */
   float zoomx = (BLI_rcti_size_x(rect) - 2.0f) / BLI_rctf_size_x(&profile->view_rect);
   float zoomy = (BLI_rcti_size_y(rect) - 2.0f) / BLI_rctf_size_y(&profile->view_rect);
   float offsx = profile->view_rect.xmin - (1.0f / zoomx);
   float offsy = profile->view_rect.ymin - (1.0f / zoomy);
 
-  /* Exit early if too narrow */
+  /* Exit early if too narrow. */
   if (zoomx == 0.0f) {
     return;
   }
 
-  /* Test needed because path can draw outside of boundary */
+  /* Test needed because path can draw outside of boundary. */
   int scissor[4];
   GPU_scissor_get_i(scissor);
   rcti scissor_new = {
@@ -2208,7 +2221,7 @@ void ui_draw_but_CURVEPROFILE(ARegion *region,
   uint pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
   immBindBuiltinProgram(GPU_SHADER_2D_UNIFORM_COLOR);
 
-  /* Backdrop */
+  /* Draw the backdrop. */
   float color_backdrop[4] = {0, 0, 0, 1};
   if (profile->flag & PROF_USE_CLIP) {
     gl_shaded_color_get_fl((uchar *)wcol->inner, -20, color_backdrop);
@@ -2227,33 +2240,33 @@ void ui_draw_but_CURVEPROFILE(ARegion *region,
     immRectf(pos, rect->xmin, rect->ymin, rect->xmax, rect->ymax);
   }
 
-  /* 0.25 step grid */
+  /* 0.25 step grid. */
   gl_shaded_color((uchar *)wcol->inner, -16);
   ui_draw_but_curve_grid(pos, rect, zoomx, zoomy, offsx, offsy, 0.25f);
-  /* 1.0 step grid */
+  /* 1.0 step grid. */
   gl_shaded_color((uchar *)wcol->inner, -24);
   ui_draw_but_curve_grid(pos, rect, zoomx, zoomy, offsx, offsy, 1.0f);
 
-  /* Draw the path's fill */
+  /* Draw the path's fill. */
   if (profile->table == NULL) {
-    BKE_curveprofile_update(profile, false);
+    BKE_curveprofile_update(profile, PROF_UPDATE_NONE);
   }
   CurveProfilePoint *pts = profile->table;
-  /* Also add the last points on the right and bottom edges to close off the fill polygon */
+  /* Also add the last points on the right and bottom edges to close off the fill polygon. */
   bool add_left_tri = profile->view_rect.xmin < 0.0f;
   bool add_bottom_tri = profile->view_rect.ymin < 0.0f;
   uint tot_points = (uint)PROF_N_TABLE(profile->path_len) + 1 + add_left_tri + add_bottom_tri;
   uint tot_triangles = tot_points - 2;
 
-  /* Create array of the positions of the table's points */
+  /* Create array of the positions of the table's points. */
   float(*table_coords)[2] = MEM_mallocN(sizeof(*table_coords) * tot_points, "table x coords");
   for (i = 0; i < (uint)PROF_N_TABLE(profile->path_len);
-       i++) { /* Only add the points from the table here */
+       i++) { /* Only add the points from the table here. */
     table_coords[i][0] = pts[i].x;
     table_coords[i][1] = pts[i].y;
   }
   if (add_left_tri && add_bottom_tri) {
-    /* Add left side, bottom left corner, and bottom side points */
+    /* Add left side, bottom left corner, and bottom side points. */
     table_coords[tot_points - 3][0] = profile->view_rect.xmin;
     table_coords[tot_points - 3][1] = 1.0f;
     table_coords[tot_points - 2][0] = profile->view_rect.xmin;
@@ -2262,30 +2275,30 @@ void ui_draw_but_CURVEPROFILE(ARegion *region,
     table_coords[tot_points - 1][1] = profile->view_rect.ymin;
   }
   else if (add_left_tri) {
-    /* Add the left side and bottom left corner points */
+    /* Add the left side and bottom left corner points. */
     table_coords[tot_points - 2][0] = profile->view_rect.xmin;
     table_coords[tot_points - 2][1] = 1.0f;
     table_coords[tot_points - 1][0] = profile->view_rect.xmin;
     table_coords[tot_points - 1][1] = 0.0f;
   }
   else if (add_bottom_tri) {
-    /* Add the bottom side and bottom left corner points */
+    /* Add the bottom side and bottom left corner points. */
     table_coords[tot_points - 2][0] = 0.0f;
     table_coords[tot_points - 2][1] = profile->view_rect.ymin;
     table_coords[tot_points - 1][0] = 1.0f;
     table_coords[tot_points - 1][1] = profile->view_rect.ymin;
   }
   else {
-    /* Just add the bottom corner point. Side points would be redundant anyway */
+    /* Just add the bottom corner point. Side points would be redundant anyway. */
     table_coords[tot_points - 1][0] = 0.0f;
     table_coords[tot_points - 1][1] = 0.0f;
   }
 
-  /* Calculate the table point indices of the triangles for the profile's fill */
+  /* Calculate the table point indices of the triangles for the profile's fill. */
   uint(*tri_indices)[3] = MEM_mallocN(sizeof(*tri_indices) * tot_triangles, "return tri indices");
   BLI_polyfill_calc(table_coords, tot_points, -1, tri_indices);
 
-  /* Draw the triangles for the profile fill */
+  /* Draw the triangles for the profile fill. */
   immUniformColor3ubvAlpha((const uchar *)wcol->item, 128);
   GPU_blend(true);
   GPU_polygon_smooth(false);
@@ -2301,7 +2314,7 @@ void ui_draw_but_CURVEPROFILE(ARegion *region,
   immEnd();
   MEM_freeN(tri_indices);
 
-  /* Draw the profile's path so the edge stands out a bit */
+  /* Draw the profile's path so the edge stands out a bit. */
   tot_points -= (add_left_tri + add_left_tri);
   GPU_line_width(1.0f);
   immUniformColor3ubvAlpha((const uchar *)wcol->item, 255);
@@ -2313,9 +2326,44 @@ void ui_draw_but_CURVEPROFILE(ARegion *region,
     immVertex2f(pos, fx, fy);
   }
   immEnd();
-  immUnbindProgram();
   MEM_freeN(table_coords);
 
+  /* Draw the handles for the selected control points. */
+  pts = profile->path;
+  tot_points = (uint)profile->path_len;
+  int selected_free_points = 0;
+  for (i = 0; i < tot_points; i++) {
+    if (point_draw_handles(&pts[i])) {
+      selected_free_points++;
+    }
+  }
+  /* Draw the lines to the handles from the points. */
+  if (selected_free_points > 0) {
+    GPU_line_width(1.0f);
+    gl_shaded_color((uchar *)wcol->inner, -24);
+    GPU_line_smooth(true);
+    immBegin(GPU_PRIM_LINES, selected_free_points * 4);
+    float ptx, pty;
+    for (i = 0; i < tot_points; i++) {
+      if (point_draw_handles(&pts[i])) {
+        ptx = rect->xmin + zoomx * (pts[i].x - offsx);
+        pty = rect->ymin + zoomy * (pts[i].y - offsy);
+
+        fx = rect->xmin + zoomx * (pts[i].h1_loc[0] - offsx);
+        fy = rect->ymin + zoomy * (pts[i].h1_loc[1] - offsy);
+        immVertex2f(pos, ptx, pty);
+        immVertex2f(pos, fx, fy);
+
+        fx = rect->xmin + zoomx * (pts[i].h2_loc[0] - offsx);
+        fy = rect->ymin + zoomy * (pts[i].h2_loc[1] - offsy);
+        immVertex2f(pos, ptx, pty);
+        immVertex2f(pos, fx, fy);
+      }
+    }
+    immEnd();
+  }
+  immUnbindProgram();
+
   /* New GPU instructions for control points and sampled points. */
   format = immVertexFormat();
   pos = GPU_vertformat_attr_add(format, "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
@@ -2339,8 +2387,6 @@ void ui_draw_but_CURVEPROFILE(ARegion *region,
   }
 
   /* Draw the control points. */
-  pts = profile->path;
-  tot_points = (uint)profile->path_len;
   GPU_line_smooth(false);
   GPU_blend(false);
   GPU_point_size(max_ff(3.0f, min_ff(UI_DPI_FAC / but->block->aspect * 5.0f, 5.0f)));
@@ -2353,6 +2399,28 @@ void ui_draw_but_CURVEPROFILE(ARegion *region,
   }
   immEnd();
 
+  /* Draw the handle points. */
+  if (selected_free_points > 0) {
+    GPU_line_smooth(false);
+    GPU_blend(false);
+    GPU_point_size(max_ff(2.0f, min_ff(UI_DPI_FAC / but->block->aspect * 4.0f, 4.0f)));
+    immBegin(GPU_PRIM_POINTS, selected_free_points * 2);
+    for (i = 0; i < tot_points; i++) {
+      if (point_draw_handles(&pts[i])) {
+        fx = rect->xmin + zoomx * (pts[i].h1_loc[0] - offsx);
+        fy = rect->ymin + zoomy * (pts[i].h1_loc[1] - offsy);
+        immAttr4fv(col, (pts[i].flag & PROF_H1_SELECT) ? color_vert_select : color_vert);
+        immVertex2f(pos, fx, fy);
+
+        fx = rect->xmin + zoomx * (pts[i].h2_loc[0] - offsx);
+        fy = rect->ymin + zoomy * (pts[i].h2_loc[1] - offsy);
+        immAttr4fv(col, (pts[i].flag & PROF_H2_SELECT) ? color_vert_select : color_vert);
+        immVertex2f(pos, fx, fy);
+      }
+    }
+    immEnd();
+  }
+
   /* Draw the sampled points in addition to the control points if they have been created */
   pts = profile->segments;
   tot_points = (uint)profile->segments_len;
@@ -2367,7 +2435,6 @@ void ui_draw_but_CURVEPROFILE(ARegion *region,
     }
     immEnd();
   }
-
   immUnbindProgram();
 
   /* restore scissortest */