Adding example to makefile

Author: fjtrujy

src/samples/Makefile.am

@@ -21,6 +21,7 @@ SAMPLES = \
 	gu/clut \
 	gu/common \
 	gu/copy \
+	gu/doublelist \
 	gu/cube \
 	gu/envmap \
 	gu/integerdrawing \
@@ -43,6 +44,7 @@ SAMPLES = \
 	gu/text \
 	gu/timing \
 	gu/vertex \
+	gu/vsync30FPS \
 	gu/zbufferfog \
 	ir/sircs \
 	ir/irda \

src/samples/Makefile.samples

@@ -18,6 +18,7 @@ SAMPLES = \
 	gu/clut \
 	gu/copy \
 	gu/cube \
+	gu/doublelist \
 	gu/envmap \
 	gu/integerdrawing \
 	gu/lights \
@@ -40,6 +41,7 @@ SAMPLES = \
 	gu/text \
 	gu/timing \
 	gu/vertex \
+	gu/vsync30FPS \
 	gu/zbufferfog \
 	ir/sircs \
 	ir/irda \

src/samples/gu/vsync30FPS/vsync30FPS.c

@@ -3,7 +3,19 @@
  * -----------------------------------------------------------------------
  * Licensed under the BSD license, see LICENSE in PSPSDK root for details.
  *
+ * VSYNC 30FPS Sample
+ * With the sceKernelRegisterSubIntrHandler(PSP_VBLANK_INT, 0, on_vblank, NULL);,
+ * the on_vblank function is going to be executed each PSP_VBLANK_INT interruption.
+ * To force 30 FPS, we must ensure the VBLANK interruption happens exactly twice,
+ * in order to achieve this, we have used 2 semaphores, so before swapping buffers,
+ * we need to ensure that both semaphores are being signaled already, 
+ * and this is what vsync30 method does.
+ * 
+ * How there are plenty of applications whose FPS are set to 30FPS,
+ * this is just an example of how we could achieve this.
+ *
  * Copyright (c) 2005 Jesper Svennevid
+ * Copyright (c) 2025, Francisco Javier Trujillo Mata <[email protected]>
  */
 
 #include <pspkernel.h>