Pong.cpp

#define _CRT_SECURE_NO_DEPRECATE

#include "utils.cpp"
#include <windows.h>
#include <string>
#include <stdio.h>

using namespace std;

global_variable bool running = true;

struct Render_State {
	int height, width;
	void* memory;

	BITMAPINFO bitmap_info;
};

global_variable Render_State render_state;

#include "platform_common.cpp"
#include "renderer.cpp"
#include "game.cpp"

LRESULT CALLBACK window_callback(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
	LRESULT result = 0; 
	switch (uMsg) {
		case WM_CLOSE:
		case WM_DESTROY: {
			running = false;
		} break;

		case WM_SIZE: {
			RECT rect;
			GetClientRect(hwnd, &rect);
			render_state.width = rect.right - rect.left;
			render_state.height = rect.bottom - rect.top;

			int size = render_state.width * render_state.height * sizeof(unsigned int);
			if (render_state.memory) VirtualFree(render_state.memory, 0, MEM_RELEASE);
			render_state.memory = VirtualAlloc(0, size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);

		render_state.bitmap_info.bmiHeader.biSize = sizeof(render_state.bitmap_info.bmiHeader);
		render_state.bitmap_info.bmiHeader.biWidth = render_state.width;
		render_state.bitmap_info.bmiHeader.biHeight = render_state.height;
		render_state.bitmap_info.bmiHeader.biPlanes = 1;
		render_state.bitmap_info.bmiHeader.biBitCount = 32;
		render_state.bitmap_info.bmiHeader.biCompression = BI_RGB;

		} break;

		default: {
			result = DefWindowProc(hwnd, uMsg, wParam, lParam);

		}
	}
	return result;
}

int WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd) {

	// Create Window Class
	WNDCLASS window_class = {};
	window_class.style = CS_HREDRAW | CS_VREDRAW;
	window_class.lpszClassName = "Game Window Class";
	window_class.lpfnWndProc = window_callback;

	// Register Class
	RegisterClass(&window_class);

	// Create Window
	HWND window = CreateWindow(window_class.lpszClassName, "Pong", WS_OVERLAPPEDWINDOW | WS_VISIBLE, CW_USEDEFAULT, CW_USEDEFAULT, 1280, 720, 0, 0, hInstance, 0);
	HDC hdc = GetDC(window);

	Input input = {};

	float delta_time = 0.016666f;
	LARGE_INTEGER frame_begin_time;
	QueryPerformanceCounter(&frame_begin_time);

	float performance_frequency;
	{
		LARGE_INTEGER perf;
		QueryPerformanceFrequency(&perf);
		performance_frequency = (float)perf.QuadPart;
	}

	while (running) {
		// Input
		MSG message;

		for (int i = 0; i < BUTTON_COUNT; i++) {
			input.buttons[i].changed = false;
		}

		while (PeekMessage(&message, window, 0, 0, PM_REMOVE)) {
			
			switch (message.message) {
				case WM_KEYUP:
				case WM_KEYDOWN: {
					u32 vk_code = (u32)message.wParam;
					bool is_down = ((message.lParam & (1 << 31)) == 0);
					switch (vk_code) {

#define process_button(b, vk)\
case vk:{\
input.buttons[b].changed = is_down != input.buttons[b].is_down;\
input.buttons[b].is_down = is_down;\
} break;
						process_button(BUTTON_UP, VK_UP);
						process_button(BUTTON_DOWN, VK_DOWN);
						process_button(BUTTON_LEFT, VK_LEFT);
						process_button(BUTTON_RIGHT, VK_RIGHT);
						process_button(BUTTON_ENTER, VK_RETURN);
						process_button(BUTTON_BACKSPACE, VK_BACK);
						process_button(BUTTON_SPACE, VK_SPACE);
						process_button(BUTTON_A, 'A');
						process_button(BUTTON_B, 'B');
						process_button(BUTTON_C, 'C');
						process_button(BUTTON_D, 'D');
						process_button(BUTTON_E, 'E');
						process_button(BUTTON_F, 'F');
						process_button(BUTTON_G, 'G');
						process_button(BUTTON_H, 'H');
						process_button(BUTTON_I, 'I');
						process_button(BUTTON_J, 'J');
						process_button(BUTTON_K, 'K');
						process_button(BUTTON_L, 'L');
						process_button(BUTTON_M, 'M');
						process_button(BUTTON_N, 'N');
						process_button(BUTTON_O, 'O');
						process_button(BUTTON_P, 'P');
						process_button(BUTTON_Q, 'Q');
						process_button(BUTTON_R, 'R');
						process_button(BUTTON_S, 'S');
						process_button(BUTTON_T, 'T');
						process_button(BUTTON_U, 'U');
						process_button(BUTTON_V, 'V');
						process_button(BUTTON_W, 'W');
						process_button(BUTTON_X, 'X');
						process_button(BUTTON_Y, 'Y');
						process_button(BUTTON_Z, 'Z');
					}
				} break;

				default: {
					TranslateMessage(&message);
					DispatchMessage(&message);
				}
			}
		}

		// Simulate
		simulate_game(&input, delta_time);

		// Render
		StretchDIBits(hdc, 0, 0, render_state.width, render_state.height, 0, 0, render_state.width, render_state.height, render_state.memory, &render_state.bitmap_info, DIB_RGB_COLORS, SRCCOPY);

		LARGE_INTEGER frame_end_time;
		QueryPerformanceCounter(&frame_end_time);
		delta_time = (float)(frame_end_time.QuadPart - frame_begin_time.QuadPart) / performance_frequency;
		frame_begin_time = frame_end_time;
	}

}