From 3eb6cc58efe99dbb5f0756f89e19f244ea90d800 Mon Sep 17 00:00:00 2001
From: Alvie Rahman <alvierahman90@gmail.com>
Date: Sun, 12 Jun 2022 19:31:27 +0100
Subject: [PATCH] move screen drawing logic outside of main.c

---
 src/main.c   |  7 +++----
 src/sprite.c | 31 +++++++++++++++++++++++++++++++
 src/sprite.h |  3 +++
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/src/main.c b/src/main.c
index 3115be6..023103d 100644
--- a/src/main.c
+++ b/src/main.c
@@ -40,11 +40,11 @@ void main(void)
 	screen_sprites[1].bitmap_index = SI_UP;
 
 	for (i = 0; i < NO_SCREEN_SPRITES; i++) {
-		set_sprite_tile(i, screen_sprites[i].bitmap_indexes[screen_sprites[i].bitmap_index]);
-		set_sprite_prop(i, screen_sprites[i].bitmap_prop[screen_sprites[i].bitmap_index]);
+		screen_sprites[i].bitmap_index_prev = -1;
+		screen_sprites[i].gb_sprite_index = i;
 		screen_sprites[i].pos.x = 72+(8*i);
 		screen_sprites[i].pos.y = 36+(8*i);
-		move_sprite(i, screen_sprites[i].pos.x, screen_sprites[i].pos.y);
+		sprite_draw_to_screen(&(screen_sprites[i]));
 	}
 
 
@@ -54,7 +54,6 @@ void main(void)
 		jp = joypad();
 		for (i = 0; i < NO_SCREEN_SPRITES; i++) {
 			sprite_iter_frame(&(screen_sprites[i]), &map, screen_sprites[i].has_joypad ? jp : 0, &fc);
-			move_sprite(i, screen_sprites[i].pos.x, screen_sprites[i].pos.y);
 			//gprintf("x: %d y: %d\n", sprites[i].pos.x, sprites[i].pos.y);
 		}
 
diff --git a/src/sprite.c b/src/sprite.c
index b0c48b8..49fb870 100644
--- a/src/sprite.c
+++ b/src/sprite.c
@@ -15,8 +15,10 @@ typedef struct SpriteCorners {
 
 
 typedef struct Sprites {
+	int gb_sprite_index;
 	int frames_since_last_dash;
 	int frames_since_last_jump;
+	int bitmap_index_prev;
 	int bitmap_index;
 	int bitmap_indexes[8];
 	int bitmap_prop[8];
@@ -35,6 +37,8 @@ void get_sprite_corners(Sprite *sprite, SpriteCorners *r);
 void sprite_iter_frame(Sprite *sprite, Map *map, int joypad, unsigned int *fc);
 unsigned int sprite_internal_collision(Map *map, Sprite *sprite);
 unsigned int sprite_collision(Map *map, Sprite *sprite);
+void sprite_draw_to_screen(Sprite *sprite);
+void sprite_update_bitmap(Sprite *sprite);
 
 
 int get_tile_index_by_coord(unsigned int x, unsigned int y)
@@ -147,6 +151,9 @@ void sprite_iter_frame(Sprite *sprite, Map *map, int joypad, unsigned int *fc)
 
 		if (!sprite_internal_collision(map, sprite)) break;
 	}
+
+	sprite_update_bitmap(sprite);
+	sprite_draw_to_screen(sprite);
 }
 
 
@@ -185,3 +192,27 @@ unsigned int sprite_collision(Map *map, Sprite *sprite)
 
 	return rv;
 }
+
+void sprite_update_bitmap(Sprite *sprite)
+{
+	sprite->bitmap_index_prev = sprite->bitmap_index;
+
+	     if ((sprite->vel.y > 0) && (sprite->vel.x > 0)) sprite->bitmap_index = SI_DOWN_RIGHT;
+	else if ((sprite->vel.y < 0) && (sprite->vel.x > 0)) sprite->bitmap_index = SI_UP_RIGHT;
+	else if ((sprite->vel.y > 0) && (sprite->vel.x < 0)) sprite->bitmap_index = SI_DOWN_LEFT;
+	else if ((sprite->vel.y < 0) && (sprite->vel.x < 0)) sprite->bitmap_index = SI_UP_LEFT;
+
+	else if ( sprite->vel.y < 0)                         sprite->bitmap_index = SI_UP;
+	else if ( sprite->vel.y > 0)                         sprite->bitmap_index = SI_DOWN;
+	else if ( sprite->vel.x > 0)                         sprite->bitmap_index = SI_RIGHT;
+	else if ( sprite->vel.x < 0)                         sprite->bitmap_index = SI_LEFT;
+}
+
+void sprite_draw_to_screen(Sprite *sprite)
+{
+	if (sprite->bitmap_index_prev != sprite->bitmap_index) {
+		set_sprite_tile(sprite->gb_sprite_index, sprite->bitmap_indexes[sprite->bitmap_index]);
+		set_sprite_prop(sprite->gb_sprite_index, sprite->bitmap_prop[sprite->bitmap_index]);
+	}
+	move_sprite(sprite->gb_sprite_index, sprite->pos.x, sprite->pos.y);
+}
diff --git a/src/sprite.h b/src/sprite.h
index c37790e..9f94382 100644
--- a/src/sprite.h
+++ b/src/sprite.h
@@ -12,8 +12,10 @@ typedef struct SpriteCorners {
 } SpriteCorners;
 
 typedef struct Sprites {
+	int gb_sprite_index;
 	int frames_since_last_dash;
 	int frames_since_last_jump;
+	int bitmap_index_prev;
 	int bitmap_index;
 	int bitmap_indexes[8];
 	int bitmap_prop[8];
@@ -29,5 +31,6 @@ typedef struct Sprites {
 void sprite_iter_frame(Sprite *sprite, Map *map, int joypad, unsigned int *fc);
 unsigned int sprite_internal_collision(Map *map, Sprite *sprite);
 unsigned int sprite_collision(Map *map, Sprite *sprite);
+void sprite_draw_to_screen(Sprite *sprite);
 
 #endif