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->currentWy = 0;
67 softwareRenderer->wx = 0;
68}
69
70static void GBVideoSoftwareRendererDeinit(struct GBVideoRenderer* renderer) {
71 struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
72 UNUSED(softwareRenderer);
73}
74
75static uint8_t GBVideoSoftwareRendererWriteVideoRegister(struct GBVideoRenderer* renderer, uint16_t address, uint8_t value) {
76 struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
77 switch (address) {
78 case REG_LCDC:
79 softwareRenderer->lcdc = value;
80 break;
81 case REG_BGP:
82 softwareRenderer->palette[0] = GB_PALETTE[value & 3];
83 softwareRenderer->palette[1] = GB_PALETTE[(value >> 2) & 3];
84 softwareRenderer->palette[2] = GB_PALETTE[(value >> 4) & 3];
85 softwareRenderer->palette[3] = GB_PALETTE[(value >> 6) & 3];
86 break;
87 case REG_OBP0:
88 softwareRenderer->palette[8 * 4 + 0] = GB_PALETTE[value & 3];
89 softwareRenderer->palette[8 * 4 + 1] = GB_PALETTE[(value >> 2) & 3];
90 softwareRenderer->palette[8 * 4 + 2] = GB_PALETTE[(value >> 4) & 3];
91 softwareRenderer->palette[8 * 4 + 3] = GB_PALETTE[(value >> 6) & 3];
92 break;
93 case REG_OBP1:
94 softwareRenderer->palette[9 * 4 + 0] = GB_PALETTE[value & 3];
95 softwareRenderer->palette[9 * 4 + 1] = GB_PALETTE[(value >> 2) & 3];
96 softwareRenderer->palette[9 * 4 + 2] = GB_PALETTE[(value >> 4) & 3];
97 softwareRenderer->palette[9 * 4 + 3] = GB_PALETTE[(value >> 6) & 3];
98 break;
99 case REG_SCY:
100 softwareRenderer->scy = value;
101 break;
102 case REG_SCX:
103 softwareRenderer->scx = value;
104 break;
105 case REG_WY:
106 softwareRenderer->wy = value;
107 break;
108 case REG_WX:
109 softwareRenderer->wx = value;
110 break;
111 }
112 return value;
113}
114
115static void GBVideoSoftwareRendererDrawDot(struct GBVideoRenderer* renderer, int x, int y, struct GBObj** obj, size_t oamMax) {
116 struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
117 uint8_t* maps = &softwareRenderer->d.vram[GB_BASE_MAP];
118 if (GBRegisterLCDCIsTileMap(softwareRenderer->lcdc)) {
119 maps += GB_SIZE_MAP;
120 }
121 if (GBRegisterLCDCIsBgEnable(softwareRenderer->lcdc)) {
122 GBVideoSoftwareRendererDrawBackground(softwareRenderer, maps, x, y, softwareRenderer->scx, softwareRenderer->scy);
123
124 if (GBRegisterLCDCIsWindow(softwareRenderer->lcdc) && softwareRenderer->wy <= y && x >= softwareRenderer->wx - 7) {
125 maps = &softwareRenderer->d.vram[GB_BASE_MAP];
126 if (GBRegisterLCDCIsWindowTileMap(softwareRenderer->lcdc)) {
127 maps += GB_SIZE_MAP;
128 }
129 GBVideoSoftwareRendererDrawBackground(softwareRenderer, maps, x, y, 7 - softwareRenderer->wx, (softwareRenderer->currentWy - y) - softwareRenderer->wy);
130 if (x == 159) { // TODO: Find a better way to do this
131 ++softwareRenderer->currentWy;
132 }
133 }
134 } else {
135 softwareRenderer->row[x] = 0;
136 }
137
138 if (GBRegisterLCDCIsObjEnable(softwareRenderer->lcdc)) {
139 size_t i;
140 for (i = 0; i < oamMax; ++i) {
141 GBVideoSoftwareRendererDrawObj(softwareRenderer, obj[i], x, y);
142 }
143 }
144
145 color_t* row = &softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * y];
146 row[x] = softwareRenderer->palette[softwareRenderer->row[x]];
147}
148
149static void GBVideoSoftwareRendererFinishFrame(struct GBVideoRenderer* renderer) {
150 struct GBVideoSoftwareRenderer* softwareRenderer = (struct GBVideoSoftwareRenderer*) renderer;
151
152 if (softwareRenderer->temporaryBuffer) {
153 mappedMemoryFree(softwareRenderer->temporaryBuffer, GB_VIDEO_HORIZONTAL_PIXELS * GB_VIDEO_VERTICAL_PIXELS * 4);
154 softwareRenderer->temporaryBuffer = 0;
155 }
156 softwareRenderer->currentWy = 0;
157}
158
159static void GBVideoSoftwareRendererDrawBackground(struct GBVideoSoftwareRenderer* renderer, uint8_t* maps, int x, int y, int sx, int sy) {
160 uint8_t* data = renderer->d.vram;
161 if (!GBRegisterLCDCIsTileData(renderer->lcdc)) {
162 data += 0x1000;
163 }
164 int topY = (((y + sy) >> 3) & 0x1F) * 0x20;
165 int bottomY = (y + sy) & 7;
166 int topX = ((x + sx) >> 3) & 0x1F;
167 int bottomX = 7 - ((x + sx) & 7);
168 int bgTile;
169 if (GBRegisterLCDCIsTileData(renderer->lcdc)) {
170 bgTile = maps[topX + topY];
171 } else {
172 bgTile = ((int8_t*) maps)[topX + topY];
173 }
174 uint8_t tileDataLower = data[(bgTile * 8 + bottomY) * 2];
175 uint8_t tileDataUpper = data[(bgTile * 8 + bottomY) * 2 + 1];
176 tileDataUpper >>= bottomX;
177 tileDataLower >>= bottomX;
178 renderer->row[x] = ((tileDataUpper & 1) << 1) | (tileDataLower & 1);
179}
180
181static void GBVideoSoftwareRendererDrawObj(struct GBVideoSoftwareRenderer* renderer, struct GBObj* obj, int x, int y) {
182 uint8_t* data = renderer->d.vram;
183 int tileOffset = 0;
184 int bottomY;
185 if (GBObjAttributesIsYFlip(obj->attr)) {
186 bottomY = 7 - ((y - obj->y - 16) & 7);
187 if (GBRegisterLCDCIsObjSize(renderer->lcdc) && y - obj->y < -8) {
188 ++tileOffset;
189 }
190 } else {
191 bottomY = (y - obj->y - 16) & 7;
192 if (GBRegisterLCDCIsObjSize(renderer->lcdc) && y - obj->y >= -8) {
193 ++tileOffset;
194 }
195 }
196 int end = GB_VIDEO_HORIZONTAL_PIXELS;
197 if (obj->x < end) {
198 end = obj->x;
199 }
200 int ix = obj->x - 8;
201 if (x < ix || x >= ix + 8) {
202 return;
203 }
204 uint8_t mask = GBObjAttributesIsPriority(obj->attr) ? 0 : 0x20;
205 int p = (GBObjAttributesGetPalette(obj->attr) + 8) * 4;
206 int bottomX;
207 if (GBObjAttributesIsXFlip(obj->attr)) {
208 bottomX = (x - obj->x) & 7;
209 } else {
210 bottomX = 7 - ((x - obj->x) & 7);
211 }
212 int objTile = obj->tile + tileOffset;
213 uint8_t tileDataLower = data[(objTile * 8 + bottomY) * 2];
214 uint8_t tileDataUpper = data[(objTile * 8 + bottomY) * 2 + 1];
215 tileDataUpper >>= bottomX;
216 tileDataLower >>= bottomX;
217 color_t current = renderer->row[x];
218 if (((tileDataUpper | tileDataLower) & 1) && current <= mask) {
219 renderer->row[x] = p | ((tileDataUpper & 1) << 1) | (tileDataLower & 1);
220 }
221}