Handling window resizing events

README.md

@@ -7,4 +7,10 @@ It's goal is also to demonstrate **floating-point precision errors**, that's why
 * Scaling with mouse wheel.
 * No rendering if the math function returns `NaN` or `Infinity`.
 * Movable axises. Screen => Math, Math => Screen unit converters.
-* Automatically calculate scale and axis position based on interval of the math function.
+* Automatically calculate scale and axis position based on interval of the math function.
+* Pixel perfect rendering.
+
+## Demo
+![Sin demo](/screenshots/sin.png)
+![Log demo](/screenshots/log.png)
+![Sin2 demo](/screenshots/sin2.png)

main.cpp

@@ -24,7 +24,7 @@ double mathF(double x) {
 
 int main(int argc, char* argv[]) {
 
-    Grapher* grapher = new Grapher(640, 480, mathF);
+    Grapher* grapher = new Grapher(mathF);
 
     grapher->init("Grapher", "arial.ttf");
 

src/App.c++

@@ -1,8 +1,8 @@
 #include "App.h"
 #include <SDL_ttf.h>
 
-App::App(int vWidth, int vHeight): vWidth(vWidth), vHeight(vHeight) {}
-App::~App() {}
+App::App() = default;
+App::~App() = default;
 
 void App::init(const char* title) {
 
@@ -12,13 +12,21 @@ void App::init(const char* title) {
     }
 
     // window
-    window = SDL_CreateWindow(title, SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, vWidth, vHeight, SDL_WINDOW_OPENGL);
+    window = SDL_CreateWindow(
+        title,
+        SDL_WINDOWPOS_UNDEFINED,
+        SDL_WINDOWPOS_UNDEFINED,
+        640, 480,
+        SDL_WINDOW_OPENGL | SDL_WINDOW_MAXIMIZED | SDL_WINDOW_RESIZABLE
+    );
 
     if (!window) {
         running = false;
         return;
     }
 
+    // SDL_GetWindowSize(window, &vWidth, &vHeight);
+
     // renderer
     renderer = SDL_CreateRenderer(window, -1, 0);
 
@@ -27,6 +35,8 @@ void App::init(const char* title) {
         return;
     }
 
+    SDL_GetRendererOutputSize(renderer, &vWidth, &vHeight);
+
     if (TTF_Init() < 0) {
         running = false;
         return;

src/App.h

@@ -2,6 +2,7 @@
 #define ZAVU_APP_H
 
 #include <SDL.h>
+#include <iostream>
 
 class App {
 
@@ -16,7 +17,7 @@ class App {
 
     public:
 
-    App(int vWidth, int vHeight);
+    App();
     ~App();
 
     virtual void init(const char* title);
@@ -27,6 +28,14 @@ class App {
 
     }
 
+    virtual void onResized() {
+
+        // std::cout << "resized" << std::endl;
+
+        SDL_GetRendererOutputSize(renderer, &vWidth, &vHeight);
+
+    }
+
     void destroy() {
 
         SDL_DestroyRenderer(renderer);

src/Grapher.c++

@@ -127,10 +127,22 @@ void Grapher::init(const char* title, const char* fontFile) {
 
     App::init(title);
 
+    cx = vWidth / 2;
+    cy = vHeight / 2;
+
     labelFont = TTF_OpenFont(fontFile, 10);
 
 }
 
+void Grapher::onResized() {
+
+    App::onResized();
+
+    cx = vWidth / 2;
+    cy = vHeight / 2;
+
+}
+
 void Grapher::renderGraph() {
 
     SDL_SetRenderDrawColor(renderer, 0xff, 0xa0, 0xa0, 0xff);
@@ -178,6 +190,8 @@ void Grapher::renderGraph() {
 
 void Grapher::render() {
 
+    // std::cout << "W: " << vWidth << " H: " << vHeight << std::endl;
+
     renderAxes();
 
     renderGraph();
@@ -192,6 +206,19 @@ void Grapher::handleEvents() {
 
         switch (currentEvent.type) {
 
+            case SDL_WINDOWEVENT_RESIZED:
+            case SDL_WINDOWEVENT_SIZE_CHANGED:
+                onResized();
+                break;
+
+            case SDL_WINDOWEVENT:
+
+                if (currentEvent.window.event == SDL_WINDOWEVENT_RESIZED) {
+                    onResized();
+                }
+
+                break;
+
             case SDL_QUIT:
                 running = false;
                 break;

src/Grapher.h

@@ -19,16 +19,13 @@ class Grapher : public App {
 
     public:
 
-    Grapher(int vWidth, int vHeight, mathFunction_t mathFunction) :
-        mathFunction(mathFunction),
-        cx(vWidth / 2),
-        cy(vHeight / 2),
-        App(vWidth, vHeight) {}
+    Grapher(mathFunction_t mathFunction) : mathFunction(mathFunction) {}
 
     ~Grapher();
 
     void run();
     void init(const char* title, const char* fontFile);
+    void onResized();
 
     private: