restore code for framebuffer lecture to original

commit 6aa1d2ea52df8e885a770cf567adb216e0a29cfa
Author: Julie Zelenski <[email protected]>
Date:   Tue Nov 12 20:38:06 2024 -0800

    restore code for framebuffer lecture to original

Author: Julie Zelenski

lectures/Framebuffer/code/clear/clear.c

@@ -43,7 +43,6 @@ static void clear_int_by_int_green(void) {
     int npixels = module.width * module.height;
     for (int i = 0; i < npixels; i++) {
         *im++ = 0xff00ff00; // green
-        timer_delay_us(1);
     }
 }
 
@@ -70,7 +69,7 @@ void main(void) {
 
     printf("Screen size %d x %d\n", hdmi_get_screen_width(), hdmi_get_screen_height());
     printf("Framebuffer size %d x %d\n", module.width, module.height);
-   // clear_char_by_char();
+    clear_char_by_char();
     while (1) {
         if (!confirm("clear to white, char by char")) break;
         clear_char_by_char();

lectures/Framebuffer/code/doublebuffer/hello.c

@@ -4,7 +4,7 @@
 
 void main(void) {
     uart_init();
-    gl_init(800, 600, GL_DOUBLEBUFFER); // change to GL_DOUBLEBUFFER instead
+    gl_init(800, 600, GL_SINGLEBUFFER); // change to GL_DOUBLEBUFFER instead
 
     printf("Enter any key to exit: ");
     while (!uart_haschar()) {