From eed5ac7586ced65ab42d082d030f8c60a92c431e Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Thu, 25 Jan 2024 21:19:06 -0500
Subject: [PATCH] Make window resizable

---
 src/app.d | 48 +++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 39 insertions(+), 9 deletions(-)

diff --git a/src/app.d b/src/app.d
index 1cccc59..8c8f3b6 100644
--- a/src/app.d
+++ b/src/app.d
@@ -13,15 +13,16 @@ ColorShader color_shader;
 Array spinny_vao;
 GLuint program_id;
 mat4 view_matrix;
+int window_width;
+int window_height;
 
-void init()
+private void init()
 {
     glActiveTexture(GL_TEXTURE0);
     glEnable(GL_BLEND);
     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
     glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
-    glClearColor (1.0, 0.6, 0.0, 0.0);
-    glViewport(0, 0, WIDTH, HEIGHT);
+    glClearColor(1.0, 0.6, 0.0, 0.0);
 
     spinny_vao = new Array();
     spinny_vao.bind();
@@ -69,14 +70,21 @@ fragment:
     ibo.bind();
 }
 
-void display(SDL_Window * window)
+private void resize(int width, int height)
+{
+    window_width = width;
+    window_height = height;
+    glViewport(0, 0, width, height);
+}
+
+private void display(SDL_Window * window)
 {
     glClear(GL_COLOR_BUFFER_BIT);
 
     color_shader.use();
     spinny_vao.bind();
     view_matrix.make_identity();
-    view_matrix.scale(HEIGHT / cast(float)WIDTH, 1.0, 1.0);
+    view_matrix.scale(window_height / cast(float)window_width, 1.0, 1.0);
     view_matrix.rotatez(SDL_GetTicks() / 500.0);
     color_shader.set_view(view_matrix.value_ptr);
     glDrawElements(GL_TRIANGLE_FAN, 4, GL_UNSIGNED_SHORT, null);
@@ -99,7 +107,7 @@ int main()
                                            SDL_WINDOWPOS_UNDEFINED,
                                            WIDTH,
                                            HEIGHT,
-                                           SDL_WINDOW_OPENGL);
+                                           SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);
 
     if (window == null)
     {
@@ -116,17 +124,39 @@ int main()
     }
 
     init();
+    resize(WIDTH, HEIGHT);
     SDL_Event event;
+outer:
     for (;;)
     {
         if (SDL_PollEvent(&event))
         {
-            if (event.type == SDL_QUIT)
-                break;
-            else if (event.type == SDL_KEYDOWN)
+            switch (event.type)
             {
+            case SDL_QUIT:
+                break outer;
+
+            case SDL_KEYDOWN:
                 if (event.key.keysym.scancode == SDL_SCANCODE_ESCAPE)
+                {
+                    break outer;
+                }
+                break;
+
+            case SDL_WINDOWEVENT:
+                switch (event.window.event)
+                {
+                case SDL_WINDOWEVENT_RESIZED:
+                    resize(event.window.data1, event.window.data2);
                     break;
+
+                default:
+                    break;
+                }
+                break;
+
+            default:
+                break;
             }
         }
         display(window);