add resizing to win32

2 files changed, 44 insertions, 27 deletions

diff --git a/platform_win32.c b/platform_win32.c
index a41b135..1d7ff57 100644
--- a/platform_win32.c
+++ b/platform_win32.c
@@ -1,5 +1,6 @@
 #define UNICODE
 #include <windows.h>
+#include <assert.h>
 
 #define SPONGE_IMPLEMENTATION
 #include "sponge.h"
@@ -7,10 +8,35 @@
 #include "example.h"
 
 // TODO(kard): ofc some resizing stuff
-#define WIDTH 256
-#define HEIGHT 256
+#define DEFAULT_WIDTH 256
+#define DEFAULT_HEIGHT 256
 
-static uint32_t pixel_buffer[WIDTH * HEIGHT];
+static size_t pixels_buffer_count;
+static sponge_Texture canvas;
+static BITMAPINFO bmi;
+
+int update_canvas(sponge_Texture *canvas, uint32_t new_width, uint32_t new_height) {
+    size_t new_count = new_width * new_height;
+    if (new_count > pixels_buffer_count) {
+        uint32_t *new_pixels_buffer = malloc(new_count * sizeof(uint32_t));
+        if (!new_pixels_buffer)
+            return 0;
+        free(canvas->pixels);
+        canvas->pixels = new_pixels_buffer;
+        pixels_buffer_count = new_count;
+    }
+    canvas->width = new_width;
+    canvas->height = new_height;
+    canvas->stride = new_width; // TODO(kard): think about this if we want image to stay the same without redraw
+
+    ZeroMemory(&bmi, sizeof(bmi));
+    bmi.bmiHeader.biSize        = sizeof(BITMAPINFOHEADER);
+    bmi.bmiHeader.biWidth       = new_width;
+    bmi.bmiHeader.biHeight      = -(int32_t)new_height; // negative = top-down
+    bmi.bmiHeader.biPlanes      = 1;
+    bmi.bmiHeader.biBitCount    = 32;
+    bmi.bmiHeader.biCompression = BI_RGB;
+}
 
 LRESULT WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
     switch (uMsg) {
@@ -18,6 +44,12 @@ LRESULT WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
             PostQuitMessage(0);
             return 0;
         }
+        case WM_SIZE: {
+            uint32_t width = LOWORD(lParam);
+            uint32_t height = HIWORD(lParam);
+            // TODO(kard): handle properly? (what does that even mean)
+            assert(update_canvas(&canvas, width, height));
+        }
         default:
             return DefWindowProc(hwnd, uMsg, wParam, lParam);
     }
@@ -43,8 +75,8 @@ int WinMain(
         0,
         CLASS_NAME,
         L"sponge",
-        WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX, // bla bla you can't resize window basically
-        CW_USEDEFAULT, CW_USEDEFAULT, WIDTH, HEIGHT,
+        WS_OVERLAPPEDWINDOW,
+        CW_USEDEFAULT, CW_USEDEFAULT, DEFAULT_WIDTH, DEFAULT_HEIGHT,
         NULL,
         NULL,
         hInstance,
@@ -54,23 +86,9 @@ int WinMain(
     if (hwnd == NULL)
         return 1;
 
-    ShowWindow(hwnd, nShowCmd);
-
-    BITMAPINFO bmi;
-    ZeroMemory(&bmi, sizeof(bmi));
-    bmi.bmiHeader.biSize        = sizeof(BITMAPINFOHEADER);
-    bmi.bmiHeader.biWidth       = WIDTH;
-    bmi.bmiHeader.biHeight      = -HEIGHT; // negative = top-down
-    bmi.bmiHeader.biPlanes      = 1;
-    bmi.bmiHeader.biBitCount    = 32;
-    bmi.bmiHeader.biCompression = BI_RGB;
+    update_canvas(&canvas, DEFAULT_WIDTH, DEFAULT_HEIGHT);
 
-    sponge_Texture canvas = {
-        .pixels = pixel_buffer,
-        .width = WIDTH,
-        .height = HEIGHT,
-        .stride = WIDTH,
-    };
+    ShowWindow(hwnd, nShowCmd);
 
     MSG msg = {0};
     BOOL running = TRUE;
@@ -88,16 +106,15 @@ int WinMain(
 
         if (!running) break;
 
-
-        // NOTE(kard): ACTUAL RENDERING CODE HERE !!!
         draw_frame(canvas);
 
         HDC hdc = GetDC(hwnd);
         StretchDIBits(
             hdc,
-            0, 0, WIDTH, HEIGHT, // dest rectangle
-            0, 0, WIDTH, HEIGHT, // src rectangle
-            pixel_buffer,
+            // TODO(kard): check what happens if canvas is bigger than window (it shouldn't differ currently)
+            0, 0, canvas.width, canvas.height, // dest rectangle
+            0, 0, canvas.width, canvas.height, // src rectangle
+            canvas.pixels,
             &bmi,
             DIB_RGB_COLORS,
             SRCCOPY
diff --git a/run.bat b/run.bat
index e5916e5..913a542 100644
--- a/run.bat
+++ b/run.bat
@@ -1,3 +1,3 @@
 del out.exe
-cl platform_win32.c "examples\%1" user32.lib gdi32.lib /Fe:out.exe
+cl platform_win32.c "examples\%1" user32.lib gdi32.lib /W3 /Fe:out.exe
 out.exe