#2512 - Equilibrium Half Arrows are displayed incorrect when saved t…

…o PNG (svg) by default size (#2537)

api/tests/integration/ref/rendering/render_reactions.py.out

@@ -11,3 +11,5 @@ issue 2457 wrong chiral label position
 issue_2457.png rendering status: OK
 issue 2444 wrong arrow and plus width
 issue_2444.png rendering status: OK
+issue 2512 two short equilibrium half arrows
+issue_2512.png rendering status: OK

api/tests/integration/tests/rendering/reactions/issue_2512.ket

@@ -0,0 +1,141 @@
+{
+    "root": {
+        "nodes": [
+            {
+                "$ref": "mol0"
+            },
+            {
+                "$ref": "mol1"
+            },
+            {
+                "type": "arrow",
+                "data": {
+                    "mode": "unbalanced-equilibrium-filled-half-triangle",
+                    "pos": [
+                        {
+                            "x": 13.700000000000001,
+                            "y": -7.95,
+                            "z": 0
+                        },
+                        {
+                            "x": 14.700000000000001,
+                            "y": -7.95,
+                            "z": 0
+                        }
+                    ]
+                }
+            }
+        ],
+        "connections": [],
+        "templates": []
+    },
+    "mol0": {
+        "type": "molecule",
+        "atoms": [
+            {
+                "label": "C",
+                "location": [
+                    12.549374214363931,
+                    -8.432470415521406,
+                    0
+                ]
+            },
+            {
+                "label": "C",
+                "location": [
+                    13.55062578563607,
+                    -8.432470415521406,
+                    0
+                ]
+            },
+            {
+                "label": "C",
+                "location": [
+                    13.050050188048687,
+                    -7.567529584478595,
+                    0
+                ]
+            }
+        ],
+        "bonds": [
+            {
+                "type": 1,
+                "atoms": [
+                    0,
+                    1
+                ]
+            },
+            {
+                "type": 1,
+                "atoms": [
+                    1,
+                    2
+                ]
+            },
+            {
+                "type": 1,
+                "atoms": [
+                    2,
+                    0
+                ]
+            }
+        ],
+        "stereoFlagPosition": {
+            "x": 13.55062578563607,
+            "y": 6.567529584478595,
+            "z": 0
+        }
+    },
+    "mol1": {
+        "type": "molecule",
+        "atoms": [
+            {
+                "label": "C",
+                "location": [
+                    14.774374214363931,
+                    -8.482470415521407,
+                    0
+                ]
+            },
+            {
+                "label": "C",
+                "location": [
+                    15.77562578563607,
+                    -8.482470415521407,
+                    0
+                ]
+            },
+            {
+                "label": "C",
+                "location": [
+                    15.275050188048686,
+                    -7.6175295844785955,
+                    0
+                ]
+            }
+        ],
+        "bonds": [
+            {
+                "type": 1,
+                "atoms": [
+                    0,
+                    1
+                ]
+            },
+            {
+                "type": 1,
+                "atoms": [
+                    1,
+                    2
+                ]
+            },
+            {
+                "type": 1,
+                "atoms": [
+                    2,
+                    0
+                ]
+            }
+        ]
+    }
+}

api/tests/integration/tests/rendering/render_reactions.py

@@ -93,6 +93,18 @@ def renderRxnfile(filename, outfile):
 renderer.renderToFile(rxn, joinPathPy("out/" + png_fname, __file__))
 print(checkImageSimilarity(png_fname))
 
+print("issue 2512 two short equilibrium half arrows")
+indigo.resetOptions()
+indigo.setOption("ignore-stereochemistry-errors", "true")
+indigo.setOption("render-background-color", "255, 255, 255")
+indigo.setOption("render-output-format", "png")
+fname = "issue_2512"
+png_fname = fname + ".png"
+ket_fname = joinPathPy("reactions/%s.ket" % fname, __file__)
+rxn = indigo.loadReactionFromFile(ket_fname)
+renderer.renderToFile(rxn, joinPathPy("out/" + png_fname, __file__))
+print(checkImageSimilarity(png_fname))
+
 if isIronPython():
     renderer.Dispose()
     indigo.Dispose()

core/render2d/src/render_context.cpp

@@ -1337,11 +1337,20 @@ void RenderContext::drawEquillibriumHalf(const Vec2f& p1, const Vec2f& p2, const
     n.negate();
     pa.addScaled(n, headwidth);
     pb.addScaled(n, headwidth);
+    const float default_shift = headsize * 2.0f;
+    float shift = default_shift;
+    if ((len - shift * 2.0f) < default_shift)
+    {
+        if (len < default_shift * 2.0f)
+            shift = len / 4.0f; // too short arrow - shift will be 1/4 of arrow length, short part - 1/2
+        else
+            shift = (len - default_shift) / 2.0f; // short part of arrow will be headsize*2
+    }
     if (is_unbalanced)
-        pa.addScaled(d, headsize * 2);
+        pa.addScaled(d, shift);
     d.negate();
     if (is_unbalanced)
-        pb.addScaled(d, headsize * 2);
+        pb.addScaled(d, shift);
     drawHalfArrowHeader(pa, d, width, headwidth * width_scale, headsize, arrow_type);
     drawBar(pb, pa, width, margin);
     checkPathNonEmpty();