e53f0499 |
1 | /*************************************************************************************** |
2 | * Genesis Plus |
3 | * CD graphics processor |
4 | * |
5 | * Copyright (C) 2012 Eke-Eke (Genesis Plus GX) |
6 | * |
7 | * Redistribution and use of this code or any derivative works are permitted |
8 | * provided that the following conditions are met: |
9 | * |
10 | * - Redistributions may not be sold, nor may they be used in a commercial |
11 | * product or activity. |
12 | * |
13 | * - Redistributions that are modified from the original source must include the |
14 | * complete source code, including the source code for all components used by a |
15 | * binary built from the modified sources. However, as a special exception, the |
16 | * source code distributed need not include anything that is normally distributed |
17 | * (in either source or binary form) with the major components (compiler, kernel, |
18 | * and so on) of the operating system on which the executable runs, unless that |
19 | * component itself accompanies the executable. |
20 | * |
21 | * - Redistributions must reproduce the above copyright notice, this list of |
22 | * conditions and the following disclaimer in the documentation and/or other |
23 | * materials provided with the distribution. |
24 | * |
25 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
26 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
27 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
28 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
29 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
30 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
31 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
32 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
33 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
34 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
35 | * POSSIBILITY OF SUCH DAMAGE. |
36 | * |
37 | ****************************************************************************************/ |
38 | #include "genplus_types.h" |
39 | |
40 | typedef struct |
41 | { |
42 | uint32 cycles; /* current cycles count for graphics operation */ |
43 | uint32 cyclesPerLine; /* current graphics operation timings */ |
44 | uint32 dotMask; /* stamp map size mask */ |
45 | uint16 *tracePtr; /* trace vector pointer */ |
46 | uint16 *mapPtr; /* stamp map table base address */ |
47 | uint8 stampShift; /* stamp pixel shift value (related to stamp size) */ |
48 | uint8 mapShift; /* stamp map table shift value (related to stamp map size) */ |
49 | uint16 bufferOffset; /* image buffer column offset */ |
50 | uint32 bufferStart; /* image buffer start index */ |
51 | uint8 lut_prio[4][0x100][0x100]; /* WORD-RAM data writes priority lookup table */ |
52 | uint8 lut_pixel[0x200]; /* Graphics operation dot offset lookup table */ |
53 | uint8 lut_cell[0x100]; /* Graphics operation stamp offset lookup table */ |
54 | } gfx_t; |
55 | |
56 | static gfx_t gfx; |
57 | |
58 | /***************************************************************/ |
59 | /* Rotation / Scaling operation (2M Mode) */ |
60 | /***************************************************************/ |
61 | |
62 | void gfx_init(void) |
63 | { |
64 | int i, j; |
65 | uint16 offset; |
66 | uint8 mask, row, col, temp; |
67 | |
68 | memset(&gfx, 0, sizeof(gfx)); |
69 | |
70 | /* Initialize priority modes lookup table */ |
71 | for (i=0; i<0x100; i++) |
72 | { |
73 | for (j=0; j<0x100; j++) |
74 | { |
75 | /* normal */ |
76 | gfx.lut_prio[0][i][j] = j; |
77 | /* underwrite */ |
78 | gfx.lut_prio[1][i][j] = ((i & 0x0f) ? (i & 0x0f) : (j & 0x0f)) | ((i & 0xf0) ? (i & 0xf0) : (j & 0xf0)); |
79 | /* overwrite */ |
80 | gfx.lut_prio[2][i][j] = ((j & 0x0f) ? (j & 0x0f) : (i & 0x0f)) | ((j & 0xf0) ? (j & 0xf0) : (i & 0xf0)); |
81 | /* invalid */ |
82 | gfx.lut_prio[3][i][j] = i; |
83 | } |
84 | } |
85 | |
86 | /* Initialize cell lookup table */ |
87 | /* table entry = yyxxshrr (8 bits) */ |
88 | /* with: yy = cell row (0-3) */ |
89 | /* xx = cell column (0-3) */ |
90 | /* s = stamp size (0=16x16, 1=32x32) */ |
91 | /* hrr = HFLIP & ROTATION bits */ |
92 | for (i=0; i<0x100; i++) |
93 | { |
94 | /* one stamp = 2x2 cells (16x16) or 4x4 cells (32x32) */ |
95 | mask = (i & 8) ? 3 : 1; |
96 | row = (i >> 6) & mask; |
97 | col = (i >> 4) & mask; |
98 | |
99 | if (i & 4) { col = col ^ mask; } /* HFLIP (always first) */ |
100 | if (i & 2) { col = col ^ mask; row = row ^ mask; } /* ROLL1 */ |
101 | if (i & 1) { temp = col; col = row ^ mask; row = temp; } /* ROLL0 */ |
102 | |
103 | /* cell offset (0-3 or 0-15) */ |
104 | gfx.lut_cell[i] = row + col * (mask + 1); |
105 | } |
106 | |
107 | /* Initialize pixel lookup table */ |
108 | /* table entry = yyyxxxhrr (9 bits) */ |
109 | /* with: yyy = pixel row (0-7) */ |
110 | /* xxx = pixel column (0-7) */ |
111 | /* hrr = HFLIP & ROTATION bits */ |
112 | for (i=0; i<0x200; i++) |
113 | { |
114 | /* one cell = 8x8 pixels */ |
115 | row = (i >> 6) & 7; |
116 | col = (i >> 3) & 7; |
117 | |
118 | if (i & 4) { col = col ^ 7; } /* HFLIP (always first) */ |
119 | if (i & 2) { col = col ^ 7; row = row ^ 7; } /* ROLL1 */ |
120 | if (i & 1) { temp = col; col = row ^ 7; row = temp; } /* ROLL0 */ |
121 | |
122 | /* pixel offset (0-63) */ |
123 | gfx.lut_pixel[i] = col + row * 8; |
124 | } |
125 | } |
126 | |
127 | void gfx_reset(void) |
128 | { |
129 | /* Reset cycle counter */ |
130 | gfx.cycles = 0; |
131 | } |
132 | |
133 | int gfx_context_save(uint8 *state) |
134 | { |
135 | uint32 tmp32; |
136 | int bufferptr = 0; |
137 | |
138 | save_param(&gfx.cycles, sizeof(gfx.cycles)); |
139 | save_param(&gfx.cyclesPerLine, sizeof(gfx.cyclesPerLine)); |
140 | save_param(&gfx.dotMask, sizeof(gfx.dotMask)); |
141 | save_param(&gfx.stampShift, sizeof(gfx.stampShift)); |
142 | save_param(&gfx.mapShift, sizeof(gfx.mapShift)); |
143 | save_param(&gfx.bufferOffset, sizeof(gfx.bufferOffset)); |
144 | save_param(&gfx.bufferStart, sizeof(gfx.bufferStart)); |
145 | |
146 | tmp32 = (uint8 *)(gfx.tracePtr) - scd.word_ram_2M; |
147 | save_param(&tmp32, 4); |
148 | |
149 | tmp32 = (uint8 *)(gfx.mapPtr) - scd.word_ram_2M; |
150 | save_param(&tmp32, 4); |
151 | |
152 | return bufferptr; |
153 | } |
154 | |
155 | int gfx_context_load(uint8 *state) |
156 | { |
157 | uint32 tmp32; |
158 | int bufferptr = 0; |
159 | |
160 | load_param(&gfx.cycles, sizeof(gfx.cycles)); |
161 | load_param(&gfx.cyclesPerLine, sizeof(gfx.cyclesPerLine)); |
162 | load_param(&gfx.dotMask, sizeof(gfx.dotMask)); |
163 | load_param(&gfx.stampShift, sizeof(gfx.stampShift)); |
164 | load_param(&gfx.mapShift, sizeof(gfx.mapShift)); |
165 | load_param(&gfx.bufferOffset, sizeof(gfx.bufferOffset)); |
166 | load_param(&gfx.bufferStart, sizeof(gfx.bufferStart)); |
167 | |
168 | load_param(&tmp32, 4); |
169 | gfx.tracePtr = (uint16 *)(scd.word_ram_2M + tmp32); |
170 | |
171 | load_param(&tmp32, 4); |
172 | gfx.mapPtr = (uint16 *)(scd.word_ram_2M + tmp32); |
173 | |
174 | return bufferptr; |
175 | } |
176 | |
177 | INLINE void gfx_render(uint32 bufferIndex, uint32 width) |
178 | { |
179 | uint8 pixel_in, pixel_out; |
180 | uint16 stamp_data; |
181 | uint32 stamp_index; |
182 | |
183 | /* pixel map start position for current line (13.3 format converted to 13.11) */ |
184 | uint32 xpos = *gfx.tracePtr++ << 8; |
185 | uint32 ypos = *gfx.tracePtr++ << 8; |
186 | |
187 | /* pixel map offset values for current line (5.11 format) */ |
188 | uint32 xoffset = (int16) *gfx.tracePtr++; |
189 | uint32 yoffset = (int16) *gfx.tracePtr++; |
190 | |
191 | /* process all dots */ |
192 | while (width--) |
193 | { |
194 | /* check if stamp map is repeated */ |
195 | if (scd.regs[0x58>>1].byte.l & 0x01) |
196 | { |
197 | /* stamp map range */ |
198 | xpos &= gfx.dotMask; |
199 | ypos &= gfx.dotMask; |
200 | } |
201 | else |
202 | { |
203 | /* 24-bit range */ |
204 | xpos &= 0xffffff; |
205 | ypos &= 0xffffff; |
206 | } |
207 | |
208 | /* check if pixel is outside stamp map */ |
209 | if ((xpos | ypos) & ~gfx.dotMask) |
210 | { |
211 | /* force pixel output to 0 */ |
212 | pixel_out = 0x00; |
213 | } |
214 | else |
215 | { |
216 | /* read stamp map table data */ |
217 | stamp_data = gfx.mapPtr[(xpos >> gfx.stampShift) | ((ypos >> gfx.stampShift) << gfx.mapShift)]; |
218 | |
219 | /* stamp generator base index */ |
220 | /* sss ssssssss ccyyyxxx (16x16) or sss sssssscc ccyyyxxx (32x32) */ |
221 | /* with: s = stamp number (1 stamp = 16x16 or 32x32 pixels) */ |
222 | /* c = cell offset (0-3 for 16x16, 0-15 for 32x32) */ |
223 | /* yyy = line offset (0-7) */ |
224 | /* xxx = pixel offset (0-7) */ |
225 | stamp_index = (stamp_data & 0x7ff) << 8; |
226 | |
227 | if (stamp_index) |
228 | { |
229 | /* extract HFLIP & ROTATION bits */ |
230 | stamp_data = (stamp_data >> 13) & 7; |
231 | |
232 | /* cell offset (0-3 or 0-15) */ |
233 | /* table entry = yyxxshrr (8 bits) */ |
234 | /* with: yy = cell row (0-3) = (ypos >> (11 + 3)) & 3 */ |
235 | /* xx = cell column (0-3) = (xpos >> (11 + 3)) & 3 */ |
236 | /* s = stamp size (0=16x16, 1=32x32) */ |
237 | /* hrr = HFLIP & ROTATION bits */ |
238 | stamp_index |= gfx.lut_cell[stamp_data | ((scd.regs[0x58>>1].byte.l & 0x02) << 2 ) | ((ypos >> 8) & 0xc0) | ((xpos >> 10) & 0x30)] << 6; |
239 | |
240 | /* pixel offset (0-63) */ |
241 | /* table entry = yyyxxxhrr (9 bits) */ |
242 | /* with: yyy = pixel row (0-7) = (ypos >> 11) & 7 */ |
243 | /* xxx = pixel column (0-7) = (xpos >> 11) & 7 */ |
244 | /* hrr = HFLIP & ROTATION bits */ |
245 | stamp_index |= gfx.lut_pixel[stamp_data | ((xpos >> 8) & 0x38) | ((ypos >> 5) & 0x1c0)]; |
246 | |
247 | /* read pixel pair (2 pixels/byte) */ |
248 | pixel_out = READ_BYTE(scd.word_ram_2M, stamp_index >> 1); |
249 | |
250 | /* extract left or rigth pixel */ |
251 | if (stamp_index & 1) |
252 | { |
253 | pixel_out &= 0x0f; |
254 | } |
255 | else |
256 | { |
257 | pixel_out >>= 4; |
258 | } |
259 | } |
260 | else |
261 | { |
262 | /* stamp 0 is not used: force pixel output to 0 */ |
263 | pixel_out = 0x00; |
264 | } |
265 | } |
266 | |
267 | /* read out paired pixel data */ |
268 | pixel_in = READ_BYTE(scd.word_ram_2M, bufferIndex >> 1); |
269 | |
270 | /* update left or rigth pixel */ |
271 | if (bufferIndex & 1) |
272 | { |
273 | pixel_out |= (pixel_in & 0xf0); |
274 | } |
275 | else |
276 | { |
277 | pixel_out = (pixel_out << 4) | (pixel_in & 0x0f); |
278 | } |
279 | |
280 | /* priority mode write */ |
281 | pixel_out = gfx.lut_prio[(scd.regs[0x02>>1].w >> 3) & 0x03][pixel_in][pixel_out]; |
282 | |
283 | /* write data to image buffer */ |
284 | WRITE_BYTE(scd.word_ram_2M, bufferIndex >> 1, pixel_out); |
285 | |
286 | /* check current pixel position */ |
287 | if ((bufferIndex & 7) != 7) |
288 | { |
289 | /* next pixel */ |
290 | bufferIndex++; |
291 | } |
292 | else |
293 | { |
294 | /* next cell: increment image buffer offset by one column (minus 7 pixels) */ |
295 | bufferIndex += gfx.bufferOffset; |
296 | } |
297 | |
298 | /* increment pixel position */ |
299 | xpos += xoffset; |
300 | ypos += yoffset; |
301 | } |
302 | } |
303 | |
304 | void gfx_start(unsigned int base, int cycles) |
305 | { |
306 | /* make sure 2M mode is enabled */ |
307 | if (!(scd.regs[0x02>>1].byte.l & 0x04)) |
308 | { |
309 | uint32 mask; |
310 | |
311 | /* trace vector pointer */ |
312 | gfx.tracePtr = (uint16 *)(scd.word_ram_2M + ((base << 2) & 0x3fff8)); |
313 | |
314 | /* stamps & stamp map size */ |
315 | switch ((scd.regs[0x58>>1].byte.l >> 1) & 0x03) |
316 | { |
317 | case 0: |
318 | gfx.dotMask = 0x07ffff; /* 256x256 dots/map */ |
319 | gfx.stampShift = 11 + 4; /* 16x16 dots/stamps */ |
320 | gfx.mapShift = 4; /* 16x16 stamps/map */ |
321 | mask = 0x3fe00; /* 512 bytes/table */ |
322 | break; |
323 | |
324 | case 1: |
325 | gfx.dotMask = 0x07ffff; /* 256x256 dots/map */ |
326 | gfx.stampShift = 11 + 5; /* 32x32 dots/stamps */ |
327 | gfx.mapShift = 3; /* 8x8 stamps/map */ |
328 | mask = 0x3ff80; /* 128 bytes/table */ |
329 | break; |
330 | |
331 | case 2: |
332 | gfx.dotMask = 0x7fffff; /* 4096*4096 dots/map */ |
333 | gfx.stampShift = 11 + 4; /* 16x16 dots/stamps */ |
334 | gfx.mapShift = 8; /* 256x256 stamps/map */ |
335 | mask = 0x20000; /* 131072 bytes/table */ |
336 | break; |
337 | |
338 | case 3: |
339 | gfx.dotMask = 0x7fffff; /* 4096*4096 dots/map */ |
340 | gfx.stampShift = 11 + 5; /* 32x32 dots/stamps */ |
341 | gfx.mapShift = 7; /* 128x128 stamps/map */ |
342 | mask = 0x38000; /* 32768 bytes/table */ |
343 | break; |
344 | } |
345 | |
346 | /* stamp map table base address */ |
347 | gfx.mapPtr = (uint16 *)(scd.word_ram_2M + ((scd.regs[0x5a>>1].w << 2) & mask)); |
348 | |
349 | /* image buffer column offset (64 pixels/cell, minus 7 pixels to restart at cell beginning) */ |
350 | gfx.bufferOffset = (((scd.regs[0x5c>>1].byte.l & 0x1f) + 1) << 6) - 7; |
351 | |
352 | /* image buffer start index in dot units (2 pixels/byte) */ |
353 | gfx.bufferStart = (scd.regs[0x5e>>1].w << 3) & 0x7ffc0; |
354 | |
355 | /* add image buffer horizontal dot offset */ |
356 | gfx.bufferStart += (scd.regs[0x60>>1].byte.l & 0x3f); |
357 | |
358 | /* reset GFX chip cycle counter */ |
359 | gfx.cycles = cycles; |
360 | |
361 | /* update GFX chip timings (see AC3:Thunderhawk / Thunderstrike) */ |
362 | gfx.cyclesPerLine = 4 * 5 * scd.regs[0x62>>1].w; |
363 | |
364 | /* start graphics operation */ |
365 | scd.regs[0x58>>1].byte.h = 0x80; |
366 | } |
367 | } |
368 | |
369 | void gfx_update(int cycles) |
370 | { |
371 | /* synchronize GFX chip with SUB-CPU */ |
372 | cycles -= gfx.cycles; |
373 | |
374 | /* make sure SUB-CPU is ahead */ |
375 | if (cycles > 0) |
376 | { |
377 | /* number of lines to process */ |
378 | unsigned int lines = (cycles + gfx.cyclesPerLine - 1) / gfx.cyclesPerLine; |
379 | |
380 | /* check against remaining lines */ |
381 | if (lines < scd.regs[0x64>>1].byte.l) |
382 | { |
383 | /* update Vdot remaining size */ |
384 | scd.regs[0x64>>1].byte.l -= lines; |
385 | |
386 | /* increment cycle counter */ |
387 | gfx.cycles += lines * gfx.cyclesPerLine; |
388 | } |
389 | else |
390 | { |
391 | /* process remaining lines */ |
392 | lines = scd.regs[0x64>>1].byte.l; |
393 | |
394 | /* clear Vdot remaining size */ |
395 | scd.regs[0x64>>1].byte.l = 0; |
396 | |
397 | /* end of graphics operation */ |
398 | scd.regs[0x58>>1].byte.h = 0; |
399 | |
400 | /* level 1 interrupt enabled ? */ |
401 | if (scd.regs[0x32>>1].byte.l & 0x02) |
402 | { |
403 | /* trigger level 1 interrupt */ |
404 | scd.pending |= (1 << 1); |
405 | |
406 | /* update IRQ level */ |
407 | s68k_update_irq((scd.pending & scd.regs[0x32>>1].byte.l) >> 1); |
408 | } |
409 | } |
410 | |
411 | /* render lines */ |
412 | while (lines--) |
413 | { |
414 | /* process dots to image buffer */ |
415 | gfx_render(gfx.bufferStart, scd.regs[0x62>>1].w); |
416 | |
417 | /* increment image buffer start index for next line (8 pixels/line) */ |
418 | gfx.bufferStart += 8; |
419 | } |
420 | } |
421 | } |