From c0c028ec1207e4e5bd9f46cf51622e4c9f4b169e Mon Sep 17 00:00:00 2001
From: Camden Dixie O'Brien <cobrien@witekio.com>
Date: Sat, 18 Jan 2025 22:25:19 +0000
Subject: [PATCH] Add pause and fast-forward keys

---
 main.c | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/main.c b/main.c
index 24484c4..79ad85c 100644
--- a/main.c
+++ b/main.c
@@ -27,6 +27,8 @@
 
 #define MAX_SHADER_SIZE (8 * 1024)
 
+#define FASTFORWARD_RATE 100
+
 #if defined(CPOW_DTHETA) && defined(POWRATE)
 #error "Cannot define CPOW_DTHETA and POWRATE simulataneously"
 #endif
@@ -94,6 +96,8 @@ static params_t params = {
 	.scale = STARTSCALE,
 };
 
+static bool paused = false, fastforward = false;
+
 static void
 mouse_button_callback(GLFWwindow *window, int button, int action, int mods)
 {
@@ -119,6 +123,27 @@ mouse_button_callback(GLFWwindow *window, int button, int action, int mods)
 	params.centre.im = zy;
 }
 
+static void
+key_callback(GLFWwindow *window, int key, int scancode, int action, int mods)
+{
+	(void)window;
+	(void)scancode;
+	(void)mods;
+
+	switch (key) {
+	case GLFW_KEY_SPACE:
+		if (action == GLFW_PRESS)
+			paused = !paused;
+		break;
+	case GLFW_KEY_F:
+		if (action == GLFW_PRESS)
+			fastforward = true;
+		else if (action == GLFW_RELEASE)
+			fastforward = false;
+		break;
+	}
+}
+
 static VkShaderModule load_shader_module(VkDevice dev, const char *path)
 {
 	static char buf[MAX_SHADER_SIZE]
@@ -153,8 +178,9 @@ int main(void)
 	    mode->width, mode->height, "GPU Fractal", monitor, NULL);
 	assert(window);
 
-	// Register mouse click callback
+	// Register input callbacks
 	glfwSetMouseButtonCallback(window, mouse_button_callback);
+	glfwSetKeyCallback(window, key_callback);
 
 	// Initialise Vulkan instance.
 	const VkApplicationInfo app_info = {
@@ -646,6 +672,10 @@ int main(void)
 		result = vkQueuePresentKHR(queue, &present_info);
 		assert(result == VK_SUCCESS);
 
+		if (paused)
+			continue;
+
+		for (int i = 0; i < (fastforward ? FASTFORWARD_RATE : 1); ++i) {
 #ifdef JULIA_DTHETA
 			double complex julia = params.julia.re + I * params.julia.im;
 			julia *= julia_rotz;
@@ -667,6 +697,7 @@ int main(void)
 #ifdef POWRATE
 			params.zpow += POWRATE;
 #endif
+		}
 	}
 
 	vkDeviceWaitIdle(dev);