Add tong shader

ACKNOWLEDGEMENTS.html

@@ -548,6 +548,7 @@ https://www.reddit.com/r/gamedev/comments/5iuf3h/i_am_writting_a_3d_monster_mode
 <h1>Sam Hocevar</h1>
 <pre>
     https://gamedev.stackexchange.com/questions/98246/quaternion-slerp-and-lerp-implementation-with-overshoot
+    http://lolengine.net/blog/2013/07/27/rgb-to-hsv-in-glsl
 </pre>
 
 <h1>David Rosen</h1>

shaders/default.core.frag

@@ -86,6 +86,7 @@ uniform samplerCube environmentIrradianceMapId;
 uniform int environmentIrradianceMapEnabled;
 uniform samplerCube environmentSpecularMapId;
 uniform int environmentSpecularMapEnabled;
+uniform int tongShadingEnabled;
 
 const int MAX_LIGHTS = 8;
 const int TYPE_POINT = 0;
@@ -352,6 +353,25 @@ vec3 gammaCorrect(const in vec3 color)
     return pow(color, vec3(1.0 / gamma));
 }
 
+// http://lolengine.net/blog/2013/07/27/rgb-to-hsv-in-glsl
+vec3 rgb2hsv(vec3 c)
+{
+    vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+    vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
+    vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
+
+    float d = q.x - min(q.w, q.y);
+    float e = 1.0e-10;
+    return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
+}
+
+vec3 hsv2rgb(vec3 c)
+{
+    vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+    vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
+    return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
+}
+
 vec4 metalRoughFunction(const in vec4 baseColor,
                         const in float metalness,
                         const in float roughness,
@@ -365,24 +385,35 @@ vec4 metalRoughFunction(const in vec4 baseColor,
     // Remap roughness for a perceptually more linear correspondence
     float alpha = remapRoughness(roughness);
     
-    if (environmentIrradianceMapEnabled == 1) {
-        cLinear += pbrIblModel(worldNormal,
-            worldView,
-            baseColor.rgb,
-            metalness,
-            alpha,
-            ambientOcclusion);
-    }
+    if (tongShadingEnabled != 1) {
+        if (environmentIrradianceMapEnabled == 1) {
+            cLinear += pbrIblModel(worldNormal,
+                worldView,
+                baseColor.rgb,
+                metalness,
+                alpha,
+                ambientOcclusion);
+        }
         
-    for (int i = 0; i < lightCount; ++i) {
-        cLinear += pbrModel(i,
-                            worldPosition,
-                            worldNormal,
-                            worldView,
-                            baseColor.rgb,
-                            metalness,
-                            alpha,
-                            ambientOcclusion);
+        for (int i = 0; i < lightCount; ++i) {
+            cLinear += pbrModel(i,
+                                worldPosition,
+                                worldNormal,
+                                worldView,
+                                baseColor.rgb,
+                                metalness,
+                                alpha,
+                                ambientOcclusion);
+        }
+    } else {
+        float intensity;
+        intensity = dot(vec3(1.0, 1.0, 1.0), worldNormal);
+        
+        vec3 hsv = rgb2hsv(baseColor.rgb);
+        if (intensity > 0.966)
+            cLinear = hsv2rgb(vec3(hsv.r, hsv.g, hsv.b * 2.0));
+        else
+            cLinear = hsv2rgb(vec3(hsv.r, hsv.g, hsv.b * 0.1));
     }
 
     // Apply exposure correction

shaders/default.frag

@@ -80,6 +80,7 @@ uniform int ambientOcclusionMapEnabled;
 uniform int mousePickEnabled;
 uniform vec3 mousePickTargetPosition;
 uniform float mousePickRadius;
+uniform int tongShadingEnabled;
 
 const int MAX_LIGHTS = 8;
 const int TYPE_POINT = 0;
@@ -248,6 +249,25 @@ vec3 gammaCorrect(const in vec3 color)
     return pow(color, vec3(1.0 / gamma));
 }
 
+// http://lolengine.net/blog/2013/07/27/rgb-to-hsv-in-glsl
+vec3 rgb2hsv(vec3 c)
+{
+    vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+    vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
+    vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
+
+    float d = q.x - min(q.w, q.y);
+    float e = 1.0e-10;
+    return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
+}
+
+vec3 hsv2rgb(vec3 c)
+{
+    vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+    vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
+    return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
+}
+
 vec4 metalRoughFunction(const in vec4 baseColor,
                         const in float metalness,
                         const in float roughness,
@@ -261,15 +281,26 @@ vec4 metalRoughFunction(const in vec4 baseColor,
     // Remap roughness for a perceptually more linear correspondence
     float alpha = remapRoughness(roughness);
     
-    for (int i = 0; i < lightCount; ++i) {
-        cLinear += pbrModel(i,
-                            worldPosition,
-                            worldNormal,
-                            worldView,
-                            baseColor.rgb,
-                            metalness,
-                            alpha,
-                            ambientOcclusion);
+    if (tongShadingEnabled != 1) {
+        for (int i = 0; i < lightCount; ++i) {
+            cLinear += pbrModel(i,
+                                worldPosition,
+                                worldNormal,
+                                worldView,
+                                baseColor.rgb,
+                                metalness,
+                                alpha,
+                                ambientOcclusion);
+        }
+    } else {
+        float intensity;
+        intensity = dot(vec3(1.0, 1.0, 1.0), worldNormal);
+        
+        vec3 hsv = rgb2hsv(baseColor.rgb);
+        if (intensity > 0.966)
+            cLinear = hsv2rgb(vec3(hsv.r, hsv.g, hsv.b * 2.0));
+        else
+            cLinear = hsv2rgb(vec3(hsv.r, hsv.g, hsv.b * 0.1));
     }
 
     // Apply exposure correction

src/modelshaderprogram.cpp

@@ -58,6 +58,7 @@ ModelShaderProgram::ModelShaderProgram(bool isCoreProfile)
     m_mousePickEnabledLoc = this->uniformLocation("mousePickEnabled");
     m_mousePickTargetPositionLoc = this->uniformLocation("mousePickTargetPosition");
     m_mousePickRadiusLoc = this->uniformLocation("mousePickRadius");
+    m_tongShadingEnabledLoc = this->uniformLocation("tongShadingEnabled");
     if (m_isCoreProfile) {
         m_environmentIrradianceMapIdLoc = this->uniformLocation("environmentIrradianceMapId");
         m_environmentIrradianceMapEnabledLoc = this->uniformLocation("environmentIrradianceMapEnabled");
@@ -166,3 +167,7 @@ int ModelShaderProgram::environmentSpecularMapEnabledLoc()
     return m_environmentSpecularMapEnabledLoc;
 }
 
+int ModelShaderProgram::tongShadingEnabledLoc()
+{
+    return m_tongShadingEnabledLoc;
+}

src/modelshaderprogram.h

@@ -27,6 +27,7 @@ public:
     int environmentIrradianceMapEnabledLoc();
     int environmentSpecularMapIdLoc();
     int environmentSpecularMapEnabledLoc();
+    int tongShadingEnabledLoc();
     bool isCoreProfile();
     static const QString &loadShaderSource(const QString &name);
 private:
@@ -51,6 +52,7 @@ private:
     int m_environmentIrradianceMapEnabledLoc = 0;
     int m_environmentSpecularMapIdLoc = 0;
     int m_environmentSpecularMapEnabledLoc = 0;
+    int m_tongShadingEnabledLoc = 0;
 };
 
 #endif

src/modelwidget.cpp

@@ -7,6 +7,7 @@
 #include <QSurfaceFormat>
 #include "modelwidget.h"
 #include "util.h"
+#include "preferences.h"
 
 // Modifed from http://doc.qt.io/qt-5/qtopengl-hellogl2-glwidget-cpp.html
 
@@ -46,6 +47,13 @@ ModelWidget::ModelWidget(QWidget *parent) :
     }
     setContextMenuPolicy(Qt::CustomContextMenu);
     zoom(200);
+    
+    connect(&Preferences::instance(), &Preferences::tongShadingChanged, this, &ModelWidget::reRender);
+}
+
+void ModelWidget::reRender()
+{
+    update();
 }
 
 int ModelWidget::xRot()
@@ -173,6 +181,7 @@ void ModelWidget::paintGL()
     m_world.rotate(m_zRot / 16.0f, 0, 0, 1);
 
     m_program->bind();
+    m_program->setUniformValue(m_program->tongShadingEnabledLoc(), Preferences::instance().tongShading() ? 1 : 0);
     m_program->setUniformValue(m_program->projectionMatrixLoc(), m_projection);
     m_program->setUniformValue(m_program->modelMatrixLoc(), m_world);
     QMatrix3x3 normalMatrix = m_world.normalMatrix();

src/modelwidget.h

@@ -56,6 +56,7 @@ public slots:
     void zoom(float delta);
     void setMousePickTargetPositionInModelSpace(QVector3D position);
     void setMousePickRadius(float radius);
+    void reRender();
 signals:
     void xRotationChanged(int angle);
     void yRotationChanged(int angle);

src/preferences.cpp

@@ -15,6 +15,7 @@ void Preferences::loadDefault()
     m_componentCombineMode = CombineMode::Normal;
     m_partColor = Qt::white;
     m_flatShading = true;
+    m_tongShading = false;
     m_textureSize = 1024;
 }
 
@@ -38,6 +39,13 @@ Preferences::Preferences()
         else
             m_flatShading = isTrueValueString(value);
     }
+    {
+        QString value = m_settings.value("tongShading").toString();
+        if (value.isEmpty())
+            m_tongShading = false;
+        else
+            m_tongShading = isTrueValueString(value);
+    }
     {
         QString value = m_settings.value("textureSize").toString();
         if (!value.isEmpty())
@@ -60,6 +68,11 @@ bool Preferences::flatShading() const
     return m_flatShading;
 }
 
+bool Preferences::tongShading() const
+{
+    return m_tongShading;
+}
+
 int Preferences::textureSize() const
 {
     return m_textureSize;
@@ -92,6 +105,15 @@ void Preferences::setFlatShading(bool flatShading)
     emit flatShadingChanged();
 }
 
+void Preferences::setTongShading(bool tongShading)
+{
+    if (m_tongShading == tongShading)
+        return;
+    m_tongShading = tongShading;
+    m_settings.setValue("tongShading", tongShading ? "true" : "false");
+    emit tongShadingChanged();
+}
+
 void Preferences::setTextureSize(int textureSize)
 {
     if (m_textureSize == textureSize)
@@ -118,5 +140,6 @@ void Preferences::reset()
     emit componentCombineModeChanged();
     emit partColorChanged();
     emit flatShadingChanged();
+    emit tongShadingChanged();
     emit textureSizeChanged();
 }

src/preferences.h

@@ -14,6 +14,7 @@ public:
     CombineMode componentCombineMode() const;
     const QColor &partColor() const;
     bool flatShading() const;
+    bool tongShading() const;
     QSize documentWindowSize() const;
     void setDocumentWindowSize(const QSize&);
     int textureSize() const;
@@ -21,17 +22,20 @@ signals:
     void componentCombineModeChanged();
     void partColorChanged();
     void flatShadingChanged();
+    void tongShadingChanged();
     void textureSizeChanged();
 public slots:
     void setComponentCombineMode(CombineMode mode);
     void setPartColor(const QColor &color);
     void setFlatShading(bool flatShading);
+    void setTongShading(bool tongShading);
     void setTextureSize(int textureSize);
     void reset();
 private:
     CombineMode m_componentCombineMode;
     QColor m_partColor;
     bool m_flatShading;
+    bool m_tongShading;
     QSettings m_settings;
     int m_textureSize;
 private:

src/preferenceswidget.cpp

@@ -65,6 +65,12 @@ PreferencesWidget::PreferencesWidget(const Document *document, QWidget *parent)
         Preferences::instance().setFlatShading(flatShadingBox->isChecked());
     });
     
+    QCheckBox *tongShadingBox = new QCheckBox();
+    Theme::initCheckbox(tongShadingBox);
+    connect(tongShadingBox, &QCheckBox::stateChanged, this, [=]() {
+        Preferences::instance().setTongShading(tongShadingBox->isChecked());
+    });
+    
     QComboBox *textureSizeSelectBox = new QComboBox;
     textureSizeSelectBox->addItem("512");
     textureSizeSelectBox->addItem("1024");
@@ -78,12 +84,14 @@ PreferencesWidget::PreferencesWidget(const Document *document, QWidget *parent)
     formLayout->addRow(tr("Part color:"), colorLayout);
     formLayout->addRow(tr("Combine mode:"), combineModeSelectBox);
     formLayout->addRow(tr("Flat shading:"), flatShadingBox);
+    formLayout->addRow(tr("Tong shading:"), tongShadingBox);
     formLayout->addRow(tr("Texture size:"), textureSizeSelectBox);
     
     auto loadFromPreferences = [=]() {
         updatePickButtonColor();
         combineModeSelectBox->setCurrentIndex((int)Preferences::instance().componentCombineMode());
         flatShadingBox->setChecked(Preferences::instance().flatShading());
+        tongShadingBox->setChecked(Preferences::instance().tongShading());
         textureSizeSelectBox->setCurrentIndex(
             textureSizeSelectBox->findText(QString::number(Preferences::instance().textureSize()))
         );