From d7bb1f2eccfb9feca6533cb59196ec66a51d5278 Mon Sep 17 00:00:00 2001
From: tangstad <tangstad@pvv.ntnu.no>
Date: Mon, 14 Nov 2005 01:18:38 +0000
Subject: [PATCH] Tried using a more generic way of controlling animation in a
 sprite. No longer shows animated tetris-piece sprite though, but working on a
 nice way of adding motion paths to sprites.

---
 gba/logosplash/src/logosplash.c | 75 +++++++++++++++++----------------
 1 file changed, 38 insertions(+), 37 deletions(-)

diff --git a/gba/logosplash/src/logosplash.c b/gba/logosplash/src/logosplash.c
index 3daf250..351a1a2 100644
--- a/gba/logosplash/src/logosplash.c
+++ b/gba/logosplash/src/logosplash.c
@@ -26,10 +26,20 @@
 // storage space for palette data
 //---------------------------------------------------------------------------------
 u16 PaletteBuffer[256];
-OBJATTR s_sprite, frog_sprite, turret_sprite;
+OBJATTR s_sprite, frog_sprite;
 
 unsigned int frame;
 
+typedef struct
+{
+  OBJATTR oam;
+  u8 frames;
+  u8 direction;
+  s8 frame;
+} AnimSprite;
+
+AnimSprite turret;
+
 //---------------------------------------------------------------------------------
 void VblankInterrupt()
 //---------------------------------------------------------------------------------
@@ -47,25 +57,11 @@ void move_show_and_wait(u16 x, u16 y, u16 wait_ticks) {
   for (i=0; i<wait_ticks; i++) VBlankIntrWait();
 }
 
-void move_turret(u16 frame_delay) {
-  // assume we are in vblank
-  s8 pos;
-  u16 i;
-
-  for (pos=0; pos<5; pos++) {
-    turret_sprite.attr2 = OBJ_CHAR(522 + pos*8);
-    CpuFastSet(&turret_sprite, OAM + sizeof(s_sprite) + sizeof(frog_sprite), 
-	       COPY32 | sizeof(turret_sprite)/4);
-    for (i=0; i<frame_delay; i++) VBlankIntrWait();
-  }
-
-  for (pos=4; pos>=0; pos--) {
-    turret_sprite.attr2 = OBJ_CHAR(522 + pos*8);
-    CpuFastSet(&turret_sprite, OAM + sizeof(s_sprite) + sizeof(frog_sprite), 
-	       COPY32 | sizeof(turret_sprite)/4);
-    for (i=0; i<frame_delay; i++) VBlankIntrWait();
-  }
-  
+void update_sprite(AnimSprite* sprite, u16 char_base, u16 oam_index) {
+  sprite->oam.attr2 = OBJ_CHAR(char_base + sprite->frame*8);
+  VBlankIntrWait();
+  CpuFastSet(&sprite->oam, OAM + oam_index*sizeof(OBJATTR), 
+	     COPY32 | sizeof(OBJATTR)/4);
 }
 
 //---------------------------------------------------------------------------------
@@ -101,36 +97,41 @@ int main(void)
 
 	memset(&s_sprite, 0, sizeof(s_sprite));
 	memset(&frog_sprite, 0, sizeof(frog_sprite));
-	memset(&turret_sprite, 0, sizeof(turret_sprite));
+	memset(&turret, 0, sizeof(turret));
 	s_sprite.attr2 = OBJ_CHAR(512);
 
 	frog_sprite.attr2 = OBJ_CHAR(514);
 	frog_sprite.attr1 = OBJ_SIZE(1) | OBJ_X(175);
 	frog_sprite.attr0 = OBJ_256_COLOR | OBJ_Y(49);
 
-	turret_sprite.attr2 = OBJ_CHAR(516);
-	turret_sprite.attr1 = OBJ_SIZE(1) | OBJ_X(43);
-	turret_sprite.attr0 = OBJ_256_COLOR | OBJ_Y(73);
+	// each frame is 16x16=256 bytes
+	turret.frames = 5;
+	turret.oam.attr2 = OBJ_CHAR(516);
+	turret.oam.attr1 = OBJ_SIZE(1) | OBJ_X(43);
+	turret.oam.attr0 = OBJ_256_COLOR | OBJ_Y(73);
 
 	VBlankIntrWait();
 	CpuFastSet(&frog_sprite, OAM + sizeof(s_sprite), COPY32 | sizeof(frog_sprite)/4);
 
+	u16 i;
+
 	while (1)
 	{
-		move_turret(3);
-		move_turret(3);
-		move_turret(3);
-		move_turret(3);
+		for (i=0; i<3; i++) VBlankIntrWait();
 
-		move_show_and_wait(147, 74, 30);
-		move_show_and_wait(147, 76, 30);
-		move_show_and_wait(147, 78, 15);
-		move_show_and_wait(145, 78, 15);
-		move_show_and_wait(145, 80, 30);
-		move_show_and_wait(145, 82, 30);
-		move_show_and_wait(145, 84, 30);
-		move_show_and_wait(145, 86, 30);
-		move_show_and_wait(145, 88, 30);
+		if (turret.direction)
+		  turret.frame += 1;
+		else
+		  turret.frame -= 1;
+
+		if (turret.frame >= turret.frames) {
+		  turret.frame = turret.frames - 1;
+		  turret.direction = 0;
+		} else if (turret.frame < 0) {
+		  turret.frame = 0;
+		  turret.direction = 1;
+		}
+		update_sprite(&turret, 522, 2);
 	}
 }