1/* Copyright (c) 2013-2016 Jeffrey Pfau
 2 *
 3 * This Source Code Form is subject to the terms of the Mozilla Public
 4 * License, v. 2.0. If a copy of the MPL was not distributed with this
 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 6#ifndef GB_VIDEO_H
 7#define GB_VIDEO_H
 8
 9#include "util/common.h"
10
11#include "gb/memory.h"
12
13enum {
14	GB_VIDEO_HORIZONTAL_PIXELS = 160,
15	GB_VIDEO_VERTICAL_PIXELS = 144,
16	GB_VIDEO_VBLANK_PIXELS = 10,
17	GB_VIDEO_VERTICAL_TOTAL_PIXELS = GB_VIDEO_VERTICAL_PIXELS + GB_VIDEO_VBLANK_PIXELS,
18
19	GB_VIDEO_MODE_0_LENGTH = 203, // Estimates, figure out with more precision
20	GB_VIDEO_MODE_2_LENGTH = 81,
21	GB_VIDEO_MODE_3_LENGTH = 172,
22
23	GB_VIDEO_HORIZONTAL_LENGTH = GB_VIDEO_MODE_0_LENGTH + GB_VIDEO_MODE_2_LENGTH + GB_VIDEO_MODE_3_LENGTH,
24
25	GB_VIDEO_MODE_1_LENGTH = GB_VIDEO_HORIZONTAL_LENGTH * GB_VIDEO_VBLANK_PIXELS,
26	GB_VIDEO_TOTAL_LENGTH = GB_VIDEO_HORIZONTAL_LENGTH * GB_VIDEO_VERTICAL_TOTAL_PIXELS,
27
28	GB_BASE_MAP = 0x1800,
29	GB_SIZE_MAP = 0x0400
30};
31
32struct GBVideoRenderer {
33	void (*init)(struct GBVideoRenderer* renderer);
34	void (*reset)(struct GBVideoRenderer* renderer);
35	void (*deinit)(struct GBVideoRenderer* renderer);
36
37	uint8_t (*writeVideoRegister)(struct GBVideoRenderer* renderer, uint16_t address, uint8_t value);
38	void (*writeVRAM)(struct GBVideoRenderer* renderer, uint16_t address);
39	void (*drawScanline)(struct GBVideoRenderer* renderer, int y);
40	void (*finishFrame)(struct GBVideoRenderer* renderer);
41
42	void (*getPixels)(struct GBVideoRenderer* renderer, unsigned* stride, const void** pixels);
43	void (*putPixels)(struct GBVideoRenderer* renderer, unsigned stride, void* pixels);
44
45	uint8_t* vram;
46};
47
48DECL_BITFIELD(GBRegisterLCDC, uint8_t);
49DECL_BIT(GBRegisterLCDC, BgEnable, 0);
50DECL_BIT(GBRegisterLCDC, ObjEnable, 1);
51DECL_BIT(GBRegisterLCDC, ObjSize, 2);
52DECL_BIT(GBRegisterLCDC, TileMap, 3);
53DECL_BIT(GBRegisterLCDC, TileData, 4);
54DECL_BIT(GBRegisterLCDC, Window, 5);
55DECL_BIT(GBRegisterLCDC, WindowTileMap, 6);
56DECL_BIT(GBRegisterLCDC, Enable, 7);
57
58DECL_BITFIELD(GBRegisterSTAT, uint8_t);
59DECL_BITS(GBRegisterSTAT, Mode, 0, 2);
60DECL_BIT(GBRegisterSTAT, LYC, 2);
61DECL_BIT(GBRegisterSTAT, HblankIRQ, 3);
62DECL_BIT(GBRegisterSTAT, VblankIRQ, 4);
63DECL_BIT(GBRegisterSTAT, OAMIRQ, 5);
64DECL_BIT(GBRegisterSTAT, LYCIRQ, 6);
65
66struct GBVideo {
67	struct GB* p;
68	struct GBVideoRenderer* renderer;
69
70	int ly;
71	GBRegisterSTAT stat;
72
73	int mode;
74
75	int32_t nextEvent;
76	int32_t eventDiff;
77
78	int32_t nextMode;
79
80	uint8_t* vram;
81	uint8_t* vramBank;
82
83	int32_t frameCounter;
84	int frameskip;
85	int frameskipCounter;
86};
87
88void GBVideoInit(struct GBVideo* video);
89void GBVideoReset(struct GBVideo* video);
90void GBVideoDeinit(struct GBVideo* video);
91void GBVideoAssociateRenderer(struct GBVideo* video, struct GBVideoRenderer* renderer);
92int32_t GBVideoProcessEvents(struct GBVideo* video, int32_t cycles);
93
94void GBVideoWriteLCDC(struct GBVideo* video, GBRegisterLCDC value);
95void GBVideoWriteSTAT(struct GBVideo* video, GBRegisterSTAT value);
96
97#endif