Add x, y, z keys to change rotation axis

main.c

@@ -21,6 +21,14 @@ static const vertex_t vertices[] = {
 
 static const uint16_t indices[] = { 0, 1, 2, 2, 3, 0 };
 
+typedef enum {
+	AXIS_X,
+	AXIS_Y,
+	AXIS_Z,
+} axis_t;
+
+static axis_t rot_axis = AXIS_Y;
+
 // clang-format off
 #define ID \
 	{ \
@@ -78,11 +86,23 @@ key_callback(GLFWwindow *window, int key, int scancode, int action, int mods)
 	(void)scancode;
 	(void)mods;
 
+	if (action != GLFW_PRESS)
+		return;
+
 	switch (key) {
 	case GLFW_KEY_Q:
-		if (action == GLFW_PRESS)
 		glfwSetWindowShouldClose(window, GL_TRUE);
 		break;
+
+	case GLFW_KEY_X:
+		rot_axis = AXIS_X;
+		break;
+	case GLFW_KEY_Y:
+		rot_axis = AXIS_Y;
+		break;
+	case GLFW_KEY_Z:
+		rot_axis = AXIS_Z;
+		break;
 	}
 }
 
@@ -144,13 +164,26 @@ int main()
 	};
 	persp(mvp.proj, (float)W / H, M_PI / 6, 0.1, 10.0);
 
-	const mat4_t rot = ROT_Y(M_PI / 128);
+	const mat4_t rotx = ROT_X(M_PI / 128);
+	const mat4_t roty = ROT_Y(M_PI / 128);
+	const mat4_t rotz = ROT_Z(M_PI / 128);
+
 	while (!glfwWindowShouldClose(window)) {
 		glfwPollEvents();
 
 		mat4_t tmp;
 		memcpy(tmp, mvp.model, sizeof(mat4_t));
-		mul(mvp.model, rot, tmp);
+		switch (rot_axis) {
+		case AXIS_X:
+			mul(mvp.model, rotx, tmp);
+			break;
+		case AXIS_Y:
+			mul(mvp.model, roty, tmp);
+			break;
+		case AXIS_Z:
+			mul(mvp.model, rotz, tmp);
+			break;
+		}
 
 		gpu_render(&gpu, &mvp);
 	}