Working on adding mouse-panning and zoom.

include/FractalApp.hpp

@@ -35,6 +35,7 @@ enum class Fractal {
     MandelbrotSet, JuliaSet
 };
 
+/// This class represents the FractalApp program state.
 class FractalInspectorApp : public ReWindow::OpenGLWindow {
 protected:
     JUI::Scene *scene;
@@ -59,10 +60,13 @@ protected:
     Color4 u_rgb_4 = Colors::Green;
     Vector2 u_julia_set {0,0};
     Vector2 u_julia_value {0,0};
+    bool panning = false;
 
     Fractal current_fractal = Fractal::MandelbrotSet;
+
+    void OnShaderLoadFail(const std::string&, const std::string&);
 public:
-    FractalInspectorApp();
+    FractalInspectorApp(int width, int height);
 
     /// Returns a full-path file name for a GLSL vertex shader, from a given prefix name.
     static std::filesystem::path VertexShaderFilepathFromPrefixName(const std::string &name);
@@ -101,6 +105,8 @@ public:
     /// Performs a logic update.
     void Update(float elapsed);
 
+    float ReadableScale();
+
     /// Pushes updated shader paramters to the OpenGL shader program.
     void UpdateShaderUniforms(float elapsed);
 

main.cpp

@@ -11,7 +11,12 @@
 int main(int argc, char** argv) {
     ReWindow::Logger::Debug.EnableConsole(false);
 
-    auto* program = new FractalInspectorApp();
+    int default_app_width = 1080;
+    int default_app_height = 768;
+
+    // TODO: Create AppConfig struct and pass to constructor.
+
+    auto* program = new FractalInspectorApp(default_app_width, default_app_height);
 
     program->Open();
     program->SetFullscreen(false);

shaders/mandelbrot.frag.glsl

@@ -68,6 +68,9 @@ float iterate_mandelbrot(vec2 p) {
 void main() {
     vec2 R = u_resolution.xy;
 
+    // Unused as of yet, see TODOs for what and why.
+    float scale = (3.0 - u_scale);
+
     vec2 uv = (u_scale * gl_FragCoord.xy - R - 1.) / R.y - u_translation;
 
     float n = iterate_mandelbrot(uv) / N;

src/FractalApp.cpp

@@ -1,7 +1,9 @@
 #include <FractalApp.hpp>
 
-FractalInspectorApp::FractalInspectorApp(): ReWindow::OpenGLWindow("ReShader", 1800, 1000, 2, 1) {
-    Shader::OnCompilationErrorMessage += [this](std::string type, std::string infoLog) {
+#define GL_VER_MAJOR 2
+#define GL_VER_MINOR 1
+
+void FractalInspectorApp::OnShaderLoadFail(const std::string& type, const std::string& infoLog) {
     auto log_lines = misc::string_expand(infoLog, '\n');
     console->Log(type, Colors::Red);
     std::cerr << type << std::endl;
@@ -9,7 +11,11 @@ FractalInspectorApp::FractalInspectorApp(): ReWindow::OpenGLWindow("ReShader", 1
         console->Log(line, Colors::Red);
         std::cerr << line << std::endl;
     }
-    };
+}
+
+FractalInspectorApp::FractalInspectorApp(int width, int height):
+    OpenGLWindow("FractalInspector",width, height, GL_VER_MAJOR, GL_VER_MINOR) {
+    Shader::OnCompilationErrorMessage += [this] (auto... args) { OnShaderLoadFail(args...);};
 
     u_time = 0;
 }
@@ -439,11 +445,20 @@ void FractalInspectorApp::Update(float elapsed) {
 
     int fps = 1.f / elapsed;
 
-    std::string fps_text = std::format("FPS: {}", fps);
+
+    // TODO: Consider moving this logic deeper into the shader to make it easier to work with.
+    float readable_scale = Math::Round(ReadableScale(), 3);
+
+    std::string fps_text = std::format("Pos: {},{} Zoom: {}x FPS: {}",
+        Math::Round(u_translation.x, 2), Math::Round(u_translation.y, 2), readable_scale, fps);
 
     fps_label->SetContent(fps_text);
 }
 
+float FractalInspectorApp::ReadableScale() {
+    return 3.f - u_scale;
+}
+
 void FractalInspectorApp::UpdateShaderUniforms(float elapsed) {
     Vector2 u_res = Vector2(GetSize().x, GetSize().y);
 
@@ -507,27 +522,71 @@ void FractalInspectorApp::OnRefresh(float elapsed) {
     this->SwapBuffers();
 }
 
+enum JUI::MouseButton ToJUIEnum(const MouseButton& btn) {
+
+    if (btn == MouseButtons::Left) return JUI::MouseButton::Left;
+    if (btn == MouseButtons::Middle) return JUI::MouseButton::Middle;
+    if (btn == MouseButtons::Right) return JUI::MouseButton::Right;
+
+    // Default condition.
+    return JUI::MouseButton::Left;
+}
+
 void FractalInspectorApp::OnMouseButtonDown(const ReWindow::MouseButtonDownEvent &e) {
-    if (e.Button == MouseButtons::Left)
+
+    auto btn = ToJUIEnum(e.Button);
+
+    if (scene->ObserveMouseInput(btn, true))
+        return;
+
+    if (btn == JUI::MouseButton::Right)
+        panning = true;
+
+
+    /*if (e.Button == MouseButtons::Left)
         scene->ObserveMouseInput(JUI::MouseButton::Left, true);
     if (e.Button == MouseButtons::Middle)
         scene->ObserveMouseInput(JUI::MouseButton::Middle, true);
     if (e.Button == MouseButtons::Right)
-        scene->ObserveMouseInput(JUI::MouseButton::Right, true);
+        scene->ObserveMouseInput(JUI::MouseButton::Right, true);*/
 }
 
 void FractalInspectorApp::OnMouseButtonUp(const ReWindow::MouseButtonUpEvent &e) {
-    if (e.Button == MouseButtons::Left)
+
+
+    auto btn = ToJUIEnum(e.Button);
+
+    if (scene->ObserveMouseInput(btn, true))
+        return;
+
+    if (btn == JUI::MouseButton::Right)
+        panning = false;
+
+    /*if (e.Button == MouseButtons::Left)
         scene->ObserveMouseInput(JUI::MouseButton::Left, false);
     if (e.Button == MouseButtons::Middle)
         scene->ObserveMouseInput(JUI::MouseButton::Middle, false);
     if (e.Button == MouseButtons::Right)
-        scene->ObserveMouseInput(JUI::MouseButton::Right, false);
+        scene->ObserveMouseInput(JUI::MouseButton::Right, false);*/
 }
 
+Vector2 last{0,0};
+
 void FractalInspectorApp::OnMouseMove(const ReWindow::MouseMoveEvent &e) {
     Vector2 nmp = Vector2(e.Position.x, e.Position.y);
-    scene->ObserveMouseMovement(nmp);
+    if (scene->ObserveMouseMovement(nmp))
+        return;
+
+    // TODO: e.Delta is always 0, investigate in JUI.
+    Vector2 delta = nmp - last;
+
+    float bias_slowdown_as_we_zoom_in = 1.125f;
+    float base_slowdown = 0.005;
+
+    if (panning)
+        u_translation += delta*(1.f / ReadableScale()*bias_slowdown_as_we_zoom_in)*base_slowdown;
+
+    last = nmp;
 }
 
 void FractalInspectorApp::OnKeyDown(const ReWindow::KeyDownEvent &e) {