src/gb/renderers/software.c (view raw)
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#include "software.h"
7
8#include "gb/io.h"
9#include "util/memory.h"
10
11static void GBVideoSoftwareRendererInit(struct GBVideoRenderer* renderer);
12static void GBVideoSoftwareRendererDeinit(struct GBVideoRenderer* renderer);
13static void GBVideoSoftwareRendererReset(struct GBVideoRenderer* renderer);
14static uint8_t GBVideoSoftwareRendererWriteVideoRegister(struct GBVideoRenderer* renderer, uint16_t address, uint8_t value);
15static void GBVideoSoftwareRendererDrawDot(struct GBVideoRenderer* renderer, int x, int y, struct GBObj** obj, size_t oamMax);
16static void GBVideoSoftwareRendererFinishFrame(struct GBVideoRenderer* renderer);
17static void GBVideoSoftwareRendererGetPixels(struct GBVideoRenderer* renderer, unsigned* stride, const void** pixels);
18static void GBVideoSoftwareRendererPutPixels(struct GBVideoRenderer* renderer, unsigned stride, void* pixels);
19
20static void GBVideoSoftwareRendererDrawBackground(struct GBVideoSoftwareRenderer* renderer, uint8_t* maps, int x, int y, int sx, int sy);
21static void GBVideoSoftwareRendererDrawObj(struct GBVideoSoftwareRenderer* renderer, struct GBObj* obj, int x, int y);
22
23#ifdef COLOR_16_BIT
24#ifdef COLOR_5_6_5
25static const color_t GB_PALETTE[4] = { 0xFFFF, 0x39C7, 0x18C3, 0x0000};
26#else
27static const color_t GB_PALETTE[4] = { 0x7FFF, 0x1DE7, 0x0C63, 0x0000};
28#endif
29#else
30static const color_t GB_PALETTE[4] = { 0xFFFFFF, 0x808080, 0x404040, 0x000000};
31#endif
32
33void GBVideoSoftwareRendererCreate(struct GBVideoSoftwareRenderer* renderer) {
34 renderer->d.init = GBVideoSoftwareRendererInit;
35 renderer->d.reset = GBVideoSoftwareRendererReset;
36 renderer->d.deinit = GBVideoSoftwareRendererDeinit;
37 renderer->d.writeVideoRegister = GBVideoSoftwareRendererWriteVideoRegister;
38 renderer->d.drawDot = GBVideoSoftwareRendererDrawDot;
39 renderer->d.finishFrame = GBVideoSoftwareRendererFinishFrame;
40 renderer->d.getPixels = 0;
41 renderer->d.putPixels = 0;
42
43 renderer->temporaryBuffer = 0;
44}
45
46static void GBVideoSoftwareRendererInit(struct GBVideoRenderer* renderer) {
47 GBVideoSoftwareRendererReset(renderer);
48
49 struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
50
51 int y;
52 for (y = 0; y < GB_VIDEO_VERTICAL_PIXELS; ++y) {
53 color_t* row = &softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * y];
54 int x;
55 for (x = 0; x < GB_VIDEO_HORIZONTAL_PIXELS; ++x) {
56 row[x] = GB_PALETTE[0];
57 }
58 }
59}
60
61static void GBVideoSoftwareRendererReset(struct GBVideoRenderer* renderer) {
62 struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
63 softwareRenderer->scy = 0;
64 softwareRenderer->scx = 0;
65 softwareRenderer->wy = 0;
66 softwareRenderer->wx = 0;
67}
68
69static void GBVideoSoftwareRendererDeinit(struct GBVideoRenderer* renderer) {
70 struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
71 UNUSED(softwareRenderer);
72}
73
74static uint8_t GBVideoSoftwareRendererWriteVideoRegister(struct GBVideoRenderer* renderer, uint16_t address, uint8_t value) {
75 struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
76 switch (address) {
77 case REG_LCDC:
78 softwareRenderer->lcdc = value;
79 break;
80 case REG_BGP:
81 softwareRenderer->palette[0] = GB_PALETTE[value & 3];
82 softwareRenderer->palette[1] = GB_PALETTE[(value >> 2) & 3];
83 softwareRenderer->palette[2] = GB_PALETTE[(value >> 4) & 3];
84 softwareRenderer->palette[3] = GB_PALETTE[(value >> 6) & 3];
85 break;
86 case REG_OBP0:
87 softwareRenderer->palette[8 * 4 + 0] = GB_PALETTE[value & 3];
88 softwareRenderer->palette[8 * 4 + 1] = GB_PALETTE[(value >> 2) & 3];
89 softwareRenderer->palette[8 * 4 + 2] = GB_PALETTE[(value >> 4) & 3];
90 softwareRenderer->palette[8 * 4 + 3] = GB_PALETTE[(value >> 6) & 3];
91 break;
92 case REG_OBP1:
93 softwareRenderer->palette[9 * 4 + 0] = GB_PALETTE[value & 3];
94 softwareRenderer->palette[9 * 4 + 1] = GB_PALETTE[(value >> 2) & 3];
95 softwareRenderer->palette[9 * 4 + 2] = GB_PALETTE[(value >> 4) & 3];
96 softwareRenderer->palette[9 * 4 + 3] = GB_PALETTE[(value >> 6) & 3];
97 break;
98 case REG_SCY:
99 softwareRenderer->scy = value;
100 break;
101 case REG_SCX:
102 softwareRenderer->scx = value;
103 break;
104 case REG_WY:
105 softwareRenderer->wy = value;
106 break;
107 case REG_WX:
108 softwareRenderer->wx = value;
109 break;
110 }
111 return value;
112}
113
114static void GBVideoSoftwareRendererDrawDot(struct GBVideoRenderer* renderer, int x, int y, struct GBObj** obj, size_t oamMax) {
115 struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
116 uint8_t* maps = &softwareRenderer->d.vram[GB_BASE_MAP];
117 if (GBRegisterLCDCIsTileMap(softwareRenderer->lcdc)) {
118 maps += GB_SIZE_MAP;
119 }
120 if (GBRegisterLCDCIsBgEnable(softwareRenderer->lcdc)) {
121 GBVideoSoftwareRendererDrawBackground(softwareRenderer, maps, x, y, softwareRenderer->scx, softwareRenderer->scy);
122
123 if (GBRegisterLCDCIsWindow(softwareRenderer->lcdc) && softwareRenderer->wy <= y) {
124 maps = &softwareRenderer->d.vram[GB_BASE_MAP];
125 if (GBRegisterLCDCIsWindowTileMap(softwareRenderer->lcdc)) {
126 maps += GB_SIZE_MAP;
127 }
128 if (x >= softwareRenderer->wx - 7) {
129 GBVideoSoftwareRendererDrawBackground(softwareRenderer, maps, x, y, 7 - softwareRenderer->wx, -softwareRenderer->wy);
130 }
131 }
132 } else {
133 softwareRenderer->row[x] = 0;
134 }
135
136 if (GBRegisterLCDCIsObjEnable(softwareRenderer->lcdc)) {
137 size_t i;
138 for (i = 0; i < oamMax; ++i) {
139 GBVideoSoftwareRendererDrawObj(softwareRenderer, obj[i], x, y);
140 }
141 }
142
143 color_t* row = &softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * y];
144 row[x] = softwareRenderer->palette[softwareRenderer->row[x]];
145}
146
147static void GBVideoSoftwareRendererFinishFrame(struct GBVideoRenderer* renderer) {
148 struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
149
150 if (softwareRenderer->temporaryBuffer) {
151 mappedMemoryFree(softwareRenderer->temporaryBuffer, GB_VIDEO_HORIZONTAL_PIXELS * GB_VIDEO_VERTICAL_PIXELS * 4);
152 softwareRenderer->temporaryBuffer = 0;
153 }
154}
155
156static void GBVideoSoftwareRendererDrawBackground(struct GBVideoSoftwareRenderer* renderer, uint8_t* maps, int x, int y, int sx, int sy) {
157 uint8_t* data = renderer->d.vram;
158 if (!GBRegisterLCDCIsTileData(renderer->lcdc)) {
159 data += 0x1000;
160 }
161 int topY = (((y + sy) >> 3) & 0x1F) * 0x20;
162 int bottomY = (y + sy) & 7;
163 int topX = ((x + sx) >> 3) & 0x1F;
164 int bottomX = 7 - ((x + sx) & 7);
165 int bgTile;
166 if (GBRegisterLCDCIsTileData(renderer->lcdc)) {
167 bgTile = maps[topX + topY];
168 } else {
169 bgTile = ((int8_t*) maps)[topX + topY];
170 }
171 uint8_t tileDataLower = data[(bgTile * 8 + bottomY) * 2];
172 uint8_t tileDataUpper = data[(bgTile * 8 + bottomY) * 2 + 1];
173 tileDataUpper >>= bottomX;
174 tileDataLower >>= bottomX;
175 renderer->row[x] = ((tileDataUpper & 1) << 1) | (tileDataLower & 1);
176}
177
178static void GBVideoSoftwareRendererDrawObj(struct GBVideoSoftwareRenderer* renderer, struct GBObj* obj, int x, int y) {
179 uint8_t* data = renderer->d.vram;
180 int tileOffset = 0;
181 int bottomY;
182 if (GBObjAttributesIsYFlip(obj->attr)) {
183 bottomY = 7 - ((y - obj->y - 16) & 7);
184 if (GBRegisterLCDCIsObjSize(renderer->lcdc) && y - obj->y < -8) {
185 ++tileOffset;
186 }
187 } else {
188 bottomY = (y - obj->y - 16) & 7;
189 if (GBRegisterLCDCIsObjSize(renderer->lcdc) && y - obj->y >= -8) {
190 ++tileOffset;
191 }
192 }
193 int end = GB_VIDEO_HORIZONTAL_PIXELS;
194 if (obj->x < end) {
195 end = obj->x;
196 }
197 int ix = obj->x - 8;
198 if (x < ix || x >= ix + 8) {
199 return;
200 }
201 uint8_t mask = GBObjAttributesIsPriority(obj->attr) ? 0 : 0x20;
202 int p = (GBObjAttributesGetPalette(obj->attr) + 8) * 4;
203 int bottomX;
204 if (GBObjAttributesIsXFlip(obj->attr)) {
205 bottomX = (x - obj->x) & 7;
206 } else {
207 bottomX = 7 - ((x - obj->x) & 7);
208 }
209 int objTile = obj->tile + tileOffset;
210 uint8_t tileDataLower = data[(objTile * 8 + bottomY) * 2];
211 uint8_t tileDataUpper = data[(objTile * 8 + bottomY) * 2 + 1];
212 tileDataUpper >>= bottomX;
213 tileDataLower >>= bottomX;
214 color_t current = renderer->row[x];
215 if (((tileDataUpper | tileDataLower) & 1) && current <= mask) {
216 renderer->row[x] = p | ((tileDataUpper & 1) << 1) | (tileDataLower & 1);
217 }
218}