From ed7c89a3f405e203c26555e9749b392bd617e688 Mon Sep 17 00:00:00 2001
From: Kyle Cardoza <Kyle.Cardoza@gmail.com>
Date: Fri, 29 Mar 2024 02:04:21 -0400
Subject: [PATCH] Implementation of VERA sprite functions

---
 src/drivers/vera_sprites.c | 54 ++++++++++++++++++++++++++++++++------
 1 file changed, 46 insertions(+), 8 deletions(-)

diff --git a/src/drivers/vera_sprites.c b/src/drivers/vera_sprites.c
index d6f6b5e..e2a594a 100644
--- a/src/drivers/vera_sprites.c
+++ b/src/drivers/vera_sprites.c
@@ -12,35 +12,73 @@
 #include "drivers/vera.h"
 #include "drivers/vera_sprites.h"
 
+static inline uint32_t
+vera_get_sprite_offset(uint8_t index)
+{
+	return 0x0001FC00 + (index * 8);
+}
 
 void
 vera_sprite_set_bitmap_address(uint8_t index, uint32_t address)
 {
-	(void) index;
-	(void) address;
+	uint32_t sprite_address = vera_get_sprite_offset(index);
 
+	address = address >> 5;
+
+	vera_set_addr0_incr1(sprite_address);
+	vera_poke_data0((uint8_t)(address & 0x000000FF));
+	vera_poke_data0((uint8_t)(address & 0x0000FF00) >> 8);
 }
 
 uint32_t
 vera_sprite_get_bitmap_address(uint8_t index)
 {
-	(void) index;
-	return 0;
+	uint32_t sprite_address = vera_get_sprite_offset(index);
+	vera_set_addr0_incr1(sprite_address);
+
+	uint32_t result = 0;
+	result = (uint32_t)(vera_peek_data0());
+	result |= ((uint32_t)(vera_peek_data0()) << 8);
+	result |= (((uint32_t)(vera_peek_data0() & 0b00000001) << 16));
+
+	return result;
 }
 
 void
 vera_sprite_set_bit_depth(uint8_t index, VeraBitDepth depth)
 {
-	(void) index;
-	(void) depth;
+	uint32_t sprite_address = vera_get_sprite_offset(index);
+	vera_set_data0_address(sprite_address + 1);
+	vera_set_addr0_auto_increment(ADDR_INCREMENT_0);
+	vera_set_addr0_decrement(false);
+	uint8_t value = vera_peek_data0();
 
+	switch (depth) {
+	case VERA_DEPTH_4BPP:
+		vera_poke_data0(value & 0b01111111);
+		break;
+	case VERA_DEPTH_8BPP:
+		vera_poke_data0(value | 0b10000000);
+		break;
+	default:
+		break;
+	}
 }
 
 VeraBitDepth
 vera_sprite_get_bit_depth(uint8_t index)
 {
-	(void) index;
-	return VERA_DEPTH_1BPP;
+	uint32_t sprite_address = vera_get_sprite_offset(index);
+	vera_set_data0_address(sprite_address + 1);
+	vera_set_addr0_auto_increment(ADDR_INCREMENT_0);
+	vera_set_addr0_decrement(false);
+	uint8_t value = vera_peek_data0() & 0b10000000;
+
+	if (value == 0) {
+		return VERA_DEPTH_4BPP;
+	} else {
+		return VERA_DEPTH_8BPP;
+	}
 }
 
 void