From 1b7079f62b7c2bfe454e20bae3776a7e36e7e684 Mon Sep 17 00:00:00 2001
From: Tavmjong Bah <tavmjong@free.fr>
Date: Sun, 9 Oct 2016 20:37:54 +0200
Subject: Provide simple "preview" for mesh gradients.

(bzr r15157)
---
 src/sp-gradient.cpp | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 61 insertions(+), 2 deletions(-)

(limited to 'src/sp-gradient.cpp')

diff --git a/src/sp-gradient.cpp b/src/sp-gradient.cpp
index d3e38485b..333316697 100644
--- a/src/sp-gradient.cpp
+++ b/src/sp-gradient.cpp
@@ -46,6 +46,7 @@
 #include "sp-radial-gradient.h"
 #include "sp-mesh-gradient.h"
 #include "sp-mesh-row.h"
+#include "sp-mesh-patch.h"
 #include "sp-stop.h"
 
 /// Has to be power of 2   Seems to be unused.
@@ -229,8 +230,6 @@ SPGradient::SPGradient() : SPPaintServer(), units(),
         state(2),
         vector() {
 
-    this->has_patches = 0;
-
     this->ref = new SPGradientReference(this);
     this->ref->changedSignal().connect(sigc::bind(sigc::ptr_fun(SPGradient::gradientRefChanged), this));
 
@@ -250,6 +249,7 @@ SPGradient::SPGradient() : SPPaintServer(), units(),
     this->spread_set = FALSE;
 
     this->has_stops = FALSE;
+    this->has_patches = FALSE;
 
     this->vector.built = false;
     this->vector.stops.clear();
@@ -275,6 +275,17 @@ void SPGradient::build(SPDocument *document, Inkscape::XML::Node *repr)
             this->has_stops = TRUE;
             break;
         }
+        if (SP_IS_MESHROW(&ochild)) {
+            for (auto& ochild2: ochild.children) {
+                if (SP_IS_MESHPATCH(&ochild2)) {
+                    this->has_patches = TRUE;
+                    break;
+                }
+            }
+            if (this->has_patches == TRUE) {
+                break;
+            }
+        }
     }
 
     this->readAttr( "gradientUnits" );
@@ -470,6 +481,9 @@ void SPGradient::child_added(Inkscape::XML::Node *child, Inkscape::XML::Node *re
             }
         }
     }
+    if ( ochild && SP_IS_MESHROW(ochild) ) {
+        this->has_patches = TRUE;
+    }
 
     /// \todo Fixme: should we schedule "modified" here?
     this->requestModified(SP_OBJECT_MODIFIED_FLAG);
@@ -485,11 +499,23 @@ void SPGradient::remove_child(Inkscape::XML::Node *child)
     SPPaintServer::remove_child(child);
 
     this->has_stops = FALSE;
+    this->has_patches = FALSE;
     for (auto& ochild: children) {
         if (SP_IS_STOP(&ochild)) {
             this->has_stops = TRUE;
             break;
         }
+        if (SP_IS_MESHROW(&ochild)) {
+            for (auto& ochild2: ochild.children) {
+                if (SP_IS_MESHPATCH(&ochild2)) {
+                    this->has_patches = TRUE;
+                    break;
+                }
+            }
+            if (this->has_patches == TRUE) {
+                break;
+            }
+        }
     }
 
     if ( this->getStopCount() == 0 ) {
@@ -765,6 +791,14 @@ static bool has_stopsFN(SPGradient const *gr)
     return gr->hasStops();
 }
 
+/**
+ * True if gradient has patches (i.e. a mesh).
+ */
+static bool has_patchesFN(SPGradient const *gr)
+{
+    return gr->hasPatches();
+}
+
 /**
  * True if gradient has spread set.
  */
@@ -793,6 +827,16 @@ SPGradient *SPGradient::getVector(bool force_vector)
     return src;
 }
 
+SPGradient *SPGradient::getArray(bool force_vector)
+{
+    SPGradient * src = chase_hrefs(this, has_patchesFN);
+
+    // if (force_vector) {
+    //     src = sp_gradient_ensure_vector_normalized(src);
+    // }
+    return src;
+}
+
 /**
  * Returns the effective spread of given gradient (climbing up the refs chain if needed).
  *
@@ -1031,6 +1075,7 @@ void SPGradient::rebuildArray()
     }
 
     array.read( SP_MESHGRADIENT( this ) );
+    has_patches = array.patch_columns() > 0;
 }
 
 Geom::Affine
@@ -1132,6 +1177,20 @@ sp_gradient_create_preview_pattern(SPGradient *gr, double width)
             cairo_pattern_add_color_stop_rgba(pat, i->offset,
               i->color.v.c[0], i->color.v.c[1], i->color.v.c[2], i->opacity);
         }
+    } else {
+
+        // For the moment, use the top row of nodes for preview.
+        unsigned columns = gr->array.patch_columns();
+
+        double offset = 1.0/double(columns);
+
+        pat = cairo_pattern_create_linear(0, 0, width, 0);
+
+        for (unsigned i = 0; i < columns+1; ++i) {
+            SPMeshNode* node = gr->array.node( 0, i*3 );
+            cairo_pattern_add_color_stop_rgba(pat, i*offset,
+              node->color.v.c[0], node->color.v.c[1], node->color.v.c[2], node->opacity);
+        }
     }
 
     return pat;
-- 
cgit v1.2.3