Add pixel-perfect drawing mode for freehand tools (issue 315)

* Added new app::tools::IntertwineAsPixelPerfect intertwiner
* Added app::tools::FreehandAlgorithm enum
* Added app::tools::WellKnownIntertwiners constants

src/app/settings/freehand_algorithm.h

@@ -0,0 +1,31 @@
+/* Aseprite
+ * Copyright (C) 2001-2013  David Capello
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef APP_SETTINGS_FREEHAND_ALGORITHM_H_INCLUDED
+#define APP_SETTINGS_FREEHAND_ALGORITHM_H_INCLUDED
+
+namespace app {
+
+  enum FreehandAlgorithm {
+    kDefaultFreehandAlgorithm,
+    kPixelPerfectFreehandAlgorithm,
+  };
+
+} // namespace app
+
+#endif // APP_SETTINGS_FREEHAND_ALGORITHM_H_INCLUDED

src/app/settings/ink_type.h

@@ -41,4 +41,4 @@ namespace app {
 
 } // namespace app
 
-#endif // SETTINGS_INK_TYPE_H_INCLUDED
+#endif // APP_SETTINGS_INK_TYPE_H_INCLUDED

src/app/settings/settings.h

@@ -20,6 +20,7 @@
 #define APP_SETTINGS_SETTINGS_H_INCLUDED
 
 #include "app/color.h"
+#include "app/settings/freehand_algorithm.h"
 #include "app/settings/ink_type.h"
 #include "app/settings/rotation_algorithm.h"
 #include "gfx/point.h"
@@ -91,6 +92,7 @@ namespace app {
     virtual int getSprayWidth() = 0;
     virtual int getSpraySpeed() = 0;
     virtual InkType getInkType() = 0;
+    virtual FreehandAlgorithm getFreehandAlgorithm() = 0;
 
     virtual void setOpacity(int opacity) = 0;
     virtual void setTolerance(int tolerance) = 0;
@@ -99,6 +101,7 @@ namespace app {
     virtual void setSprayWidth(int width) = 0;
     virtual void setSpraySpeed(int speed) = 0;
     virtual void setInkType(InkType inkType) = 0;
+    virtual void setFreehandAlgorithm(FreehandAlgorithm algorithm) = 0;
 
     virtual void addObserver(ToolSettingsObserver* observer) = 0;
     virtual void removeObserver(ToolSettingsObserver* observer) = 0;

src/app/settings/settings_observers.h

@@ -20,6 +20,7 @@
 #define APP_SETTINGS_SETTINGS_OBSERVERS_H_INCLUDED
 
 #include "app/color.h"
+#include "app/settings/freehand_algorithm.h"
 #include "app/settings/ink_type.h"
 #include "app/settings/rotation_algorithm.h"
 #include "raster/pen_type.h"
@@ -51,6 +52,7 @@ namespace app {
     virtual void onSetSprayWidth(int newSprayWidth) {}
     virtual void onSetSpraySpeed(int newSpraySpeed) {}
     virtual void onSetInkType(InkType newInkType) {}
+    virtual void onSetFreehandAlgorithm(FreehandAlgorithm algorithm) {}
   };
 
   class SelectionSettingsObserver {

src/app/settings/ui_settings_impl.cpp

@@ -26,6 +26,7 @@
 #include "app/color_swatches.h"
 #include "app/ini_file.h"
 #include "app/settings/document_settings.h"
+#include "app/tools/controller.h"
 #include "app/tools/point_shape.h"
 #include "app/tools/tool.h"
 #include "app/tools/tool_box.h"
@@ -537,6 +538,7 @@ class UIToolSettingsImpl
   int m_spray_width;
   int m_spray_speed;
   InkType m_inkType;
+  FreehandAlgorithm m_freehandAlgorithm;
 
 public:
 
@@ -554,6 +556,7 @@ public:
     m_spray_width = 16;
     m_spray_speed = 32;
     m_inkType = (InkType)get_config_int(cfg_section.c_str(), "InkType", (int)kDefaultInk);
+    m_freehandAlgorithm = kDefaultFreehandAlgorithm;
 
     m_pen.enableSignals(false);
     m_pen.setType((PenType)get_config_int(cfg_section.c_str(), "PenType", (int)PEN_TYPE_CIRCLE));
@@ -566,6 +569,12 @@ public:
       m_spray_width = get_config_int(cfg_section.c_str(), "SprayWidth", m_spray_width);
       m_spray_speed = get_config_int(cfg_section.c_str(), "SpraySpeed", m_spray_speed);
     }
+
+    if (m_tool->getController(0)->isFreehand() ||
+        m_tool->getController(1)->isFreehand()) {
+      m_freehandAlgorithm = (FreehandAlgorithm)get_config_int(cfg_section.c_str(), "FreehandAlgorithm", (int)kDefaultFreehandAlgorithm);
+      setFreehandAlgorithm(m_freehandAlgorithm);
+    }
   }
 
   ~UIToolSettingsImpl()
@@ -586,6 +595,11 @@ public:
       set_config_int(cfg_section.c_str(), "SpraySpeed", m_spray_speed);
     }
 
+    if (m_tool->getController(0)->isFreehand() ||
+        m_tool->getController(1)->isFreehand()) {
+      set_config_int(cfg_section.c_str(), "FreehandAlgorithm", m_freehandAlgorithm);
+    }
+
     set_config_bool(cfg_section.c_str(), "PreviewFilled", m_previewFilled);
   }
 
@@ -598,6 +612,7 @@ public:
   int getSprayWidth() OVERRIDE { return m_spray_width; }
   int getSpraySpeed() OVERRIDE { return m_spray_speed; }
   InkType getInkType() OVERRIDE { return m_inkType; }
+  FreehandAlgorithm getFreehandAlgorithm() OVERRIDE { return m_freehandAlgorithm; }
 
   void setOpacity(int opacity) OVERRIDE { m_opacity = opacity; }
   void setTolerance(int tolerance) OVERRIDE { m_tolerance = tolerance; }
@@ -606,6 +621,21 @@ public:
   void setSprayWidth(int width) OVERRIDE { m_spray_width = width; }
   void setSpraySpeed(int speed) OVERRIDE { m_spray_speed = speed; }
   void setInkType(InkType inkType) OVERRIDE { m_inkType = inkType; }
+  void setFreehandAlgorithm(FreehandAlgorithm algorithm) OVERRIDE {
+    m_freehandAlgorithm = algorithm;
+
+    tools::ToolBox* toolBox = App::instance()->getToolBox();
+    for (int i=0; i<2; ++i) {
+      if (algorithm == kPixelPerfectFreehandAlgorithm) {
+        m_tool->setIntertwine(i, toolBox->getIntertwinerById(tools::WellKnownIntertwiners::AsPixelPerfect));
+        m_tool->setTracePolicy(i, tools::TracePolicyLast);
+      }
+      else {
+        m_tool->setIntertwine(i, toolBox->getIntertwinerById(tools::WellKnownIntertwiners::AsLines));
+        m_tool->setTracePolicy(i, tools::TracePolicyAccumulate);
+      }
+    }
+  }
 
   void addObserver(ToolSettingsObserver* observer) OVERRIDE {
     base::Observable<ToolSettingsObserver>::addObserver(observer);

src/app/tools/controller.h

@@ -35,7 +35,9 @@ namespace app {
       typedef std::vector<gfx::Point> Points;
 
       virtual ~Controller() { }
+
       virtual bool canSnapToGrid() { return true; }
+      virtual bool isFreehand() { return false; }
 
       // Called when the user starts drawing and each time a new button is
       // pressed. The controller could be sure that this method is called

src/app/tools/controllers.h

@@ -31,6 +31,10 @@ using namespace gfx;
 // Controls clicks for tools like pencil
 class FreehandController : public Controller {
 public:
+  bool isFreehand()
+  {
+    return true;
+  }
   void pressButton(Points& points, const Point& point)
   {
     points.push_back(point);

src/app/tools/intertwine.h

@@ -33,6 +33,7 @@ namespace app {
 
       virtual ~Intertwine() { }
       virtual bool snapByAngle() { return false; }
+      virtual void prepareIntertwine() { }
       virtual void joinPoints(ToolLoop* loop, const Points& points) = 0;
       virtual void fillPoints(ToolLoop* loop, const Points& points) = 0;
 

src/app/tools/intertwiners.h

@@ -220,5 +220,80 @@ public:
   }
 };
 
+class IntertwineAsPixelPerfect : public Intertwine {
+  struct PPData {
+    Points& pts;
+    ToolLoop* loop;
+    PPData(Points& pts, ToolLoop* loop) : pts(pts), loop(loop) { }
+  };
+
+  static void pixelPerfectLine(int x, int y, PPData* data)
+  {
+    gfx::Point newPoint(x, y);
+
+    if (data->pts.empty()
+      || data->pts[data->pts.size()-1] != newPoint) {
+      data->pts.push_back(newPoint);
+    }
+  }
+
+  Points m_pts;
+
+public:
+  void prepareIntertwine() OVERRIDE {
+    m_pts.clear();
+  }
+
+  void joinPoints(ToolLoop* loop, const Points& points) OVERRIDE {
+    if (points.size() == 0)
+      return;
+    else if (m_pts.empty() && points.size() == 1) {
+      m_pts = points;
+    }
+    else {
+      PPData data(m_pts, loop);
+
+      for (size_t c=0; c+1<points.size(); ++c) {
+        int x1 = points[c].x;
+        int y1 = points[c].y;
+        int x2 = points[c+1].x;
+        int y2 = points[c+1].y;
+
+        algo_line(x1, y1, x2, y2,
+          (void*)&data,
+          (AlgoPixel)&IntertwineAsPixelPerfect::pixelPerfectLine);
+      }
+    }
+
+    for (size_t c=0; c<m_pts.size(); ++c) {
+      // We ignore a pixel that is between other two pixels in the
+      // corner of a L-like shape.
+      if (c > 0 && c+1 < m_pts.size()
+        && (m_pts[c-1].x == m_pts[c].x || m_pts[c-1].y == m_pts[c].y)
+        && (m_pts[c+1].x == m_pts[c].x || m_pts[c+1].y == m_pts[c].y)
+        && m_pts[c-1].x != m_pts[c+1].x
+        && m_pts[c-1].y != m_pts[c+1].y) {
+        ++c;
+      }
+
+      doPointshapePoint(m_pts[c].x, m_pts[c].y, loop);
+    }
+  }
+
+  void fillPoints(ToolLoop* loop, const Points& points)
+  {
+    if (points.size() < 3) {
+      joinPoints(loop, points);
+      return;
+    }
+
+    // Contour
+    joinPoints(loop, points);
+
+    // Fill content
+    algo_polygon(points.size(), (const int*)&points[0], loop, (AlgoHLine)doPointshapeHline);
+  }
+};
+
 } // namespace tools
 } // namespace app

src/app/tools/tool_box.cpp

@@ -69,6 +69,13 @@ const char* WellKnownInks::Move = "move";
 const char* WellKnownInks::Blur = "blur";
 const char* WellKnownInks::Jumble = "jumble";
 
+const char* WellKnownIntertwiners::None = "none";
+const char* WellKnownIntertwiners::AsLines = "as_lines";
+const char* WellKnownIntertwiners::AsRectangles = "as_rectangles";
+const char* WellKnownIntertwiners::AsEllipses = "as_ellipses";
+const char* WellKnownIntertwiners::AsBezier = "as_bezier";
+const char* WellKnownIntertwiners::AsPixelPerfect = "as_pixel_perfect";
+
 ToolBox::ToolBox()
 {
   PRINTF("Toolbox module: installing\n");
@@ -102,11 +109,12 @@ ToolBox::ToolBox()
   m_pointshapers["floodfill"]            = new FloodFillPointShape();
   m_pointshapers["spray"]                = new SprayPointShape();
 
-  m_intertwiners["none"]                 = new IntertwineNone();
+  m_intertwiners[WellKnownIntertwiners::None] = new IntertwineNone();
-  m_intertwiners["as_lines"]             = new IntertwineAsLines();
+  m_intertwiners[WellKnownIntertwiners::AsLines] = new IntertwineAsLines();
-  m_intertwiners["as_rectangles"]        = new IntertwineAsRectangles();
+  m_intertwiners[WellKnownIntertwiners::AsRectangles] = new IntertwineAsRectangles();
-  m_intertwiners["as_ellipses"]          = new IntertwineAsEllipses();
+  m_intertwiners[WellKnownIntertwiners::AsEllipses] = new IntertwineAsEllipses();
-  m_intertwiners["as_bezier"]            = new IntertwineAsBezier();
+  m_intertwiners[WellKnownIntertwiners::AsBezier] = new IntertwineAsBezier();
+  m_intertwiners[WellKnownIntertwiners::AsPixelPerfect] = new IntertwineAsPixelPerfect();
 
   loadTools();
 
@@ -152,9 +160,14 @@ Ink* ToolBox::getInkById(const std::string& id)
   return m_inks[id];
 }
 
+Intertwine* ToolBox::getIntertwinerById(const std::string& id)
+{
+  return m_intertwiners[id];
+}
+
 void ToolBox::loadTools()
 {
-  PRINTF("Loading ASEPRITE tools\n");
+  PRINTF("Loading Aseprite tools\n");
 
   XmlDocumentRef doc(GuiXml::instance()->doc());
   TiXmlHandle handle(doc);

src/app/tools/tool_box.h

@@ -53,6 +53,15 @@ namespace app {
       extern const char* Jumble;
     };
 
+    namespace WellKnownIntertwiners {
+      extern const char* None;
+      extern const char* AsLines;
+      extern const char* AsRectangles;
+      extern const char* AsEllipses;
+      extern const char* AsBezier;
+      extern const char* AsPixelPerfect;
+    };
+
     typedef std::list<Tool*> ToolList;
     typedef ToolList::iterator ToolIterator;
     typedef ToolList::const_iterator ToolConstIterator;
@@ -75,6 +84,7 @@ namespace app {
 
       Tool* getToolById(const std::string& id);
       Ink* getInkById(const std::string& id);
+      Intertwine* getIntertwinerById(const std::string& id);
       int getGroupsCount() const { return m_groups.size(); }
 
     private:

src/app/tools/tool_loop_manager.cpp

@@ -67,6 +67,7 @@ void ToolLoopManager::prepareLoop(const Pointer& pointer)
 
   // Prepare the ink
   m_toolLoop->getInk()->prepareInk(m_toolLoop);
+  m_toolLoop->getIntertwine()->prepareIntertwine();
 
   // Prepare preview image (the destination image will be our preview
   // in the tool-loop time, so we can see what we are drawing)

src/app/ui/context_bar.cpp

@@ -27,9 +27,11 @@
 #include "app/settings/ink_type.h"
 #include "app/settings/settings.h"
 #include "app/settings/settings_observers.h"
+#include "app/tools/controller.h"
 #include "app/tools/ink.h"
 #include "app/tools/point_shape.h"
 #include "app/tools/tool.h"
+#include "app/tools/tool_box.h"
 #include "app/ui/button_set.h"
 #include "app/ui/color_button.h"
 #include "app/ui/skin/skin_theme.h"
@@ -387,6 +389,24 @@ private:
   };
 };
 
+class ContextBar::FreehandAlgorithmField : public CheckBox
+{
+public:
+  FreehandAlgorithmField() : CheckBox("Pixel-perfect") {
+  }
+
+  void onClick(Event& ev) OVERRIDE {
+    CheckBox::onClick(ev);
+
+    ISettings* settings = UIContext::instance()->getSettings();
+    Tool* currentTool = settings->getCurrentTool();
+    settings->getToolSettings(currentTool)
+      ->setFreehandAlgorithm(isSelected() ?
+        kPixelPerfectFreehandAlgorithm:
+        kDefaultFreehandAlgorithm);
+  }
+};
+
 ContextBar::ContextBar()
   : Box(JI_HORIZONTAL)
 {
@@ -412,6 +432,9 @@ ContextBar::ContextBar()
   // addChild(new InkShadeField());
   // addChild(new InkSelectionField());
 
+  addChild(m_freehandBox = new HBox());
+  m_freehandBox->addChild(m_freehandAlgo = new FreehandAlgorithmField());
+
   addChild(m_sprayBox = new HBox());
   m_sprayBox->addChild(new Label("Spray:"));
   m_sprayBox->addChild(m_sprayWidth = new SprayWidthField());
@@ -488,6 +511,8 @@ void ContextBar::onCurrentToolChange()
   m_inkType->setInkType(toolSettings->getInkType());
   m_inkOpacity->setTextf("%d", toolSettings->getOpacity());
 
+  m_freehandAlgo->setSelected(toolSettings->getFreehandAlgorithm() == kPixelPerfectFreehandAlgorithm);
+
   m_sprayWidth->setValue(toolSettings->getSprayWidth());
   m_spraySpeed->setValue(toolSettings->getSpraySpeed());
 
@@ -512,6 +537,10 @@ void ContextBar::onCurrentToolChange()
   bool hasSelectOptions = (currentTool->getInk(0)->isSelection() ||
                            currentTool->getInk(1)->isSelection());
 
+  bool isFreehand =
+    (currentTool->getController(0)->isFreehand() ||
+     currentTool->getController(1)->isFreehand());
+
   // Show/Hide fields
   m_brushLabel->setVisible(hasOpacity);
   m_brushType->setVisible(hasOpacity);
@@ -521,6 +550,7 @@ void ContextBar::onCurrentToolChange()
   m_inkLabel->setVisible(hasInk);
   m_inkType->setVisible(hasInk);
   m_inkOpacity->setVisible(hasOpacity);
+  m_freehandBox->setVisible(isFreehand);
   m_toleranceLabel->setVisible(hasTolerance);
   m_tolerance->setVisible(hasTolerance);
   m_sprayBox->setVisible(hasSprayOptions);

src/app/ui/context_bar.h

@@ -52,6 +52,7 @@ namespace app {
     class SpraySpeedField;
     class TransparentColorField;
     class RotAlgorithmField;
+    class FreehandAlgorithmField;
 
     ui::Label* m_brushLabel;
     BrushTypeField* m_brushType;
@@ -63,6 +64,8 @@ namespace app {
     InkTypeField* m_inkType;
     ui::Label* m_opacityLabel;
     InkOpacityField* m_inkOpacity;
+    ui::Box* m_freehandBox;
+    FreehandAlgorithmField* m_freehandAlgo;
     ui::Box* m_sprayBox;
     SprayWidthField* m_sprayWidth;
     SpraySpeedField* m_spraySpeed;