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[picodrive.git] / pico / cd / gfx.c
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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 "../pico_int.h"
39#include "genplus_macros.h"
40
41typedef struct
42{
43 //uint32 cycles; /* current cycles count for graphics operation */
44 //uint32 cyclesPerLine; /* current graphics operation timings */
45 uint32 dotMask; /* stamp map size mask */
46 uint32 stampMask; /* stamp number mask */
47 uint16 *tracePtr; /* trace vector pointer */
48 uint16 *mapPtr; /* stamp map table base address */
49 uint8 stampShift; /* stamp pixel shift value (related to stamp size) */
50 uint8 mapShift; /* stamp map table shift value (related to stamp map size) */
51 uint16 bufferOffset; /* image buffer column offset */
52 uint32 bufferStart; /* image buffer start index */
53 uint32 y_step; /* pico: render line step */
54 uint8 lut_prio[4][0x10][0x10]; /* WORD-RAM data writes priority lookup table */
55 uint8 lut_pixel[0x200]; /* Graphics operation dot offset lookup table */
56 uint16 lut_cell2[0x80]; /* Graphics operation stamp offset lookup table */
57 uint16 lut_cell4[0x80]; /* Graphics operation stamp offset lookup table */
58} gfx_t;
59
60static gfx_t gfx;
61
62static void gfx_schedule(void);
63
64/***************************************************************/
65/* Rotation / Scaling operation (2M Mode) */
66/***************************************************************/
67
68void gfx_init(void)
69{
70 int i, j;
71 uint8 row, col, temp;
72
73 memset(&gfx, 0, sizeof(gfx));
74
75 /* Initialize priority modes lookup table */
76 for (i = 0; i < 0x10; i++)
77 {
78 for (j = 0; j < 0x10; j++)
79 {
80 /* normal */
81 gfx.lut_prio[0][i][j] = j;
82 /* underwrite */
83 gfx.lut_prio[1][i][j] = i ? i : j;
84 /* overwrite */
85 gfx.lut_prio[2][i][j] = j ? j : i;
86 /* invalid */
87 gfx.lut_prio[3][i][j] = i;
88 }
89 }
90
91 /* Initialize cell lookup table */
92 /* table entry = yyxxhrr (7 bits) */
93 /* with: yy = cell row (0-3) */
94 /* xx = cell column (0-3) */
95 /* hrr = HFLIP & ROTATION bits */
96 for (i=0; i<0x80; i++)
97 {
98 /* one stamp = 2x2 cells (16x16) or 4x4 cells (32x32) */
99 row = (i >> 5) & 3;
100 col = (i >> 3) & 3;
101
102 if (i & 4) { col = col ^ 3; } /* HFLIP (always first) */
103 if (i & 2) { col = col ^ 3; row = row ^ 3; } /* ROLL1 */
104 if (i & 1) { temp = col; col = row ^ 3; row = temp; } /* ROLL0 */
105
106 /* cell offset (0-3 or 0-15) */
107 gfx.lut_cell2[i] = ((row&1) + (col&1) * 2) << 6;
108 gfx.lut_cell4[i] = ((row&3) + (col&3) * 4) << 6;
109 }
110
111 /* Initialize pixel lookup table */
112 /* table entry = yyyxxxhrr (9 bits) */
113 /* with: yyy = pixel row (0-7) */
114 /* xxx = pixel column (0-7) */
115 /* hrr = HFLIP & ROTATION bits */
116 for (i=0; i<0x200; i++)
117 {
118 /* one cell = 8x8 pixels */
119 row = (i >> 6) & 7;
120 col = (i >> 3) & 7;
121
122 if (i & 4) { col = col ^ 7; } /* HFLIP (always first) */
123 if (i & 2) { col = col ^ 7; row = row ^ 7; } /* ROLL1 */
124 if (i & 1) { temp = col; col = row ^ 7; row = temp; } /* ROLL0 */
125
126 /* pixel offset (0-63) */
127 gfx.lut_pixel[i] = col + row * 8;
128 }
129}
130
131int gfx_context_save(uint8 *state)
132{
133 uint32 tmp32;
134 int bufferptr = 0;
135
136 //save_param(&gfx.cycles, sizeof(gfx.cycles));
137 //save_param(&gfx.cyclesPerLine, sizeof(gfx.cyclesPerLine));
138 save_param(&gfx.dotMask, sizeof(gfx.dotMask));
139 save_param(&gfx.stampShift, sizeof(gfx.stampShift));
140 save_param(&gfx.mapShift, sizeof(gfx.mapShift));
141 save_param(&gfx.bufferOffset, sizeof(gfx.bufferOffset));
142 save_param(&gfx.bufferStart, sizeof(gfx.bufferStart));
143
144 tmp32 = (uint8 *)(gfx.tracePtr) - Pico_mcd->word_ram2M;
145 save_param(&tmp32, 4);
146
147 tmp32 = (uint8 *)(gfx.mapPtr) - Pico_mcd->word_ram2M;
148 save_param(&tmp32, 4);
149
150 save_param(&gfx.y_step, sizeof(gfx.y_step));
151 save_param(&gfx.stampMask, sizeof(gfx.stampMask));
152
153 return bufferptr;
154}
155
156int gfx_context_load(const uint8 *state)
157{
158 uint32 tmp32;
159 int bufferptr = 0;
160
161 //load_param(&gfx.cycles, sizeof(gfx.cycles));
162 //load_param(&gfx.cyclesPerLine, sizeof(gfx.cyclesPerLine));
163 load_param(&gfx.dotMask, sizeof(gfx.dotMask));
164 load_param(&gfx.stampShift, sizeof(gfx.stampShift));
165 load_param(&gfx.mapShift, sizeof(gfx.mapShift));
166 load_param(&gfx.bufferOffset, sizeof(gfx.bufferOffset));
167 load_param(&gfx.bufferStart, sizeof(gfx.bufferStart));
168
169 load_param(&tmp32, 4);
170 gfx.tracePtr = (uint16 *)(Pico_mcd->word_ram2M + tmp32);
171
172 load_param(&tmp32, 4);
173 gfx.mapPtr = (uint16 *)(Pico_mcd->word_ram2M + tmp32);
174
175 load_param(&gfx.y_step, sizeof(gfx.y_step));
176 load_param(&gfx.stampMask, sizeof(gfx.stampMask));
177
178 return bufferptr;
179}
180
181static inline int gfx_pixel(uint32 xpos, uint32 ypos, uint16 *lut_cell)
182{
183 uint16 stamp_data;
184 uint32 stamp_index;
185 uint8 pixel_out = 0x00;
186
187 /* check if pixel is outside stamp map */
188 if (((xpos | ypos) & ~gfx.dotMask) == 0)
189 {
190 /* read stamp map table data */
191 stamp_data = gfx.mapPtr[(xpos >> gfx.stampShift) | ((ypos >> gfx.stampShift) << gfx.mapShift)];
192
193 /* stamp generator base index */
194 /* sss ssssssss ccyyyxxx (16x16) or sss sssssscc ccyyyxxx (32x32) */
195 /* with: s = stamp number (1 stamp = 16x16 or 32x32 pixels) */
196 /* c = cell offset (0-3 for 16x16, 0-15 for 32x32) */
197 /* yyy = line offset (0-7) */
198 /* xxx = pixel offset (0-7) */
199 stamp_index = (stamp_data & gfx.stampMask) << 8;
200
201 if (stamp_index)
202 {
203 /* extract HFLIP & ROTATION bits */
204 stamp_data = (stamp_data >> 13) & 7;
205
206 /* cell offset (0-3 or 0-15) */
207 /* table entry = yyxxhrr (7 bits) */
208 /* with: yy = cell row (0-3) = (ypos >> (11 + 3)) & 3 */
209 /* xx = cell column (0-3) = (xpos >> (11 + 3)) & 3 */
210 /* hrr = HFLIP & ROTATION bits */
211 stamp_index |= lut_cell[stamp_data | ((ypos >> 9) & 0x60) | ((xpos >> 11) & 0x18)];
212
213 /* pixel offset (0-63) */
214 /* table entry = yyyxxxhrr (9 bits) */
215 /* with: yyy = pixel row (0-7) = (ypos >> 11) & 7 */
216 /* xxx = pixel column (0-7) = (xpos >> 11) & 7 */
217 /* hrr = HFLIP & ROTATION bits */
218 stamp_index |= gfx.lut_pixel[stamp_data | ((ypos >> 5) & 0x1c0) | ((xpos >> 8) & 0x38)];
219
220 /* read pixel pair (2 pixels/byte) */
221 pixel_out = READ_BYTE(Pico_mcd->word_ram2M, stamp_index >> 1);
222
223 /* extract left or right pixel */
224 pixel_out >>= 4 * !(stamp_index & 1);
225 pixel_out &= 0x0f;
226 }
227 }
228
229 return pixel_out;
230}
231
232#define RENDER_LOOP(N, UPDP, COND1, COND2) do { \
233 if (bufferIndex & 1) { \
234 bufferIndex ^= 1; \
235 goto right##N; /* no initial left pixel */ \
236 } \
237 /* process all dots */ \
238 while (width--) \
239 { \
240 /* left pixel */ \
241 xpos &= mask; \
242 ypos &= mask; \
243 \
244 if (COND1) { \
245 pixel_out = gfx_pixel(xpos, ypos, lut_cell); \
246 UPDP; \
247 } \
248 \
249 if (COND2) { \
250 /* read out paired pixel data */ \
251 pixel_in = READ_BYTE(Pico_mcd->word_ram2M, bufferIndex >> 1); \
252 \
253 /* priority mode write */ \
254 pixel_in = (lut_prio[(pixel_in & 0xf0) >> 4][pixel_out] << 4) | \
255 (pixel_in & 0x0f); \
256 \
257 /* write data to image buffer */ \
258 WRITE_BYTE(Pico_mcd->word_ram2M, bufferIndex >> 1, pixel_in); \
259 } \
260 \
261 /* increment pixel position */ \
262 xpos += xoffset; \
263 ypos += yoffset; \
264 \
265right##N: \
266 if (width-- == 0) break; \
267 \
268 /* right pixel */ \
269 xpos &= mask; \
270 ypos &= mask; \
271 \
272 if (COND1) { \
273 pixel_out = gfx_pixel(xpos, ypos, lut_cell); \
274 UPDP; \
275 } \
276 \
277 if (COND2) { \
278 /* read out paired pixel data */ \
279 pixel_in = READ_BYTE(Pico_mcd->word_ram2M, bufferIndex >> 1); \
280 \
281 /* priority mode write */ \
282 pixel_in = (lut_prio[pixel_in & 0x0f][pixel_out]) | \
283 (pixel_in & 0xf0); \
284 \
285 /* write data to image buffer */ \
286 WRITE_BYTE(Pico_mcd->word_ram2M, bufferIndex >> 1, pixel_in); \
287 } \
288 \
289 /* increment pixel position */ \
290 xpos += xoffset; \
291 ypos += yoffset; \
292 \
293 /* next pixel */ \
294 bufferIndex += 2; \
295 /* check current pixel position */ \
296 if ((bufferIndex & 7) == 0) \
297 { \
298 /* next cell: increment buffer offset by one column (minus 8 pixels) */ \
299 bufferIndex += gfx.bufferOffset-1; \
300 } \
301 } \
302} while (0)
303
304static void gfx_render(uint32 bufferIndex, uint32 width)
305{
306 uint8 pixel_in, pixel_out;
307 uint32 priority;
308 uint8 (*lut_prio)[0x10];
309 uint16 *lut_cell;
310 uint32 mask;
311
312 /* pixel map start position for current line (13.3 format converted to 13.11) */
313 uint32 xpos = *gfx.tracePtr++ << 8;
314 uint32 ypos = *gfx.tracePtr++ << 8;
315
316 /* pixel map offset values for current line (5.11 format) */
317 uint32 xoffset = (int16) *gfx.tracePtr++;
318 uint32 yoffset = (int16) *gfx.tracePtr++;
319
320 priority = (Pico_mcd->s68k_regs[2] << 8) | Pico_mcd->s68k_regs[3];
321 priority = (priority >> 3) & 0x03;
322 lut_prio = gfx.lut_prio[priority];
323
324 lut_cell = (Pico_mcd->s68k_regs[0x58+1] & 0x02) ? gfx.lut_cell4 : gfx.lut_cell2;
325
326 /* check if stamp map is repeated */
327 mask = 0xffffff; /* 24-bit range */
328 if (Pico_mcd->s68k_regs[0x58+1] & 0x01)
329 {
330 /* stamp map range */
331 mask = gfx.dotMask;
332 }
333
334 pixel_out = 0;
335 if (xoffset+(1U<<10) <= 1U<<11 && yoffset+(1U<<10) <= 1U<<11) {
336 /* upscaling >= 2x, test for duplicate pixels to avoid recalculation */
337 uint32 oldx, oldy;
338 oldx = oldy = ~xpos;
339 RENDER_LOOP(1, oldx = xpos;oldy = ypos, (oldx^xpos ^ oldy^ypos) >> 11, (!priority) | pixel_out);
340 } else {
341 RENDER_LOOP(3, , 1, (!priority) | pixel_out);
342 }
343}
344
345void gfx_start(uint32 base)
346{
347 /* make sure 2M mode is enabled */
348 if (!(Pico_mcd->s68k_regs[3] & 0x04))
349 {
350 uint32 mask = 0;
351 uint32 reg;
352
353 /* trace vector pointer */
354 gfx.tracePtr = (uint16 *)(Pico_mcd->word_ram2M + ((base << 2) & 0x3fff8));
355
356 /* stamps & stamp map size */
357 switch ((Pico_mcd->s68k_regs[0x58+1] >> 1) & 0x03)
358 {
359 case 0:
360 gfx.dotMask = 0x07ffff; /* 256x256 dots/map */
361 gfx.stampMask = 0x7ff; /* 16x16 dots/stamp */
362 gfx.stampShift = 11 + 4; /* 16x16 dots/stamp */
363 gfx.mapShift = 4; /* 16x16 stamps/map */
364 mask = 0x3fe00; /* 512 bytes/table */
365 break;
366
367 case 1:
368 gfx.dotMask = 0x07ffff; /* 256x256 dots/map */
369 gfx.stampMask = 0x7fc; /* 16x16 dots/stamp */
370 gfx.stampShift = 11 + 5; /* 32x32 dots/stamp */
371 gfx.mapShift = 3; /* 8x8 stamps/map */
372 mask = 0x3ff80; /* 128 bytes/table */
373 break;
374
375 case 2:
376 gfx.dotMask = 0x7fffff; /* 4096*4096 dots/map */
377 gfx.stampMask = 0x7ff; /* 16x16 dots/stamp */
378 gfx.stampShift = 11 + 4; /* 16x16 dots/stamp */
379 gfx.mapShift = 8; /* 256x256 stamps/map */
380 mask = 0x20000; /* 131072 bytes/table */
381 break;
382
383 case 3:
384 gfx.dotMask = 0x7fffff; /* 4096*4096 dots/map */
385 gfx.stampMask = 0x7fc; /* 16x16 dots/stamp */
386 gfx.stampShift = 11 + 5; /* 32x32 dots/stamp */
387 gfx.mapShift = 7; /* 128x128 stamps/map */
388 mask = 0x38000; /* 32768 bytes/table */
389 break;
390 }
391
392 /* stamp map table base address */
393 reg = (Pico_mcd->s68k_regs[0x5a] << 8) | Pico_mcd->s68k_regs[0x5b];
394 gfx.mapPtr = (uint16 *)(Pico_mcd->word_ram2M + ((reg << 2) & mask));
395
396 /* image buffer column offset (64 pixels/cell, minus 7 pixels to restart at cell beginning) */
397 gfx.bufferOffset = (((Pico_mcd->s68k_regs[0x5c+1] & 0x1f) + 1) << 6) - 7;
398
399 /* image buffer start index in dot units (2 pixels/byte) */
400 reg = (Pico_mcd->s68k_regs[0x5e] << 8) | Pico_mcd->s68k_regs[0x5f];
401 gfx.bufferStart = (reg << 3) & 0x7ffc0;
402
403 /* add image buffer horizontal dot offset */
404 gfx.bufferStart += (Pico_mcd->s68k_regs[0x60+1] & 0x3f);
405
406 /* reset GFX chip cycle counter */
407 //gfx.cycles = cycles;
408
409 /* update GFX chip timings (see AC3:Thunderhawk / Thunderstrike) */
410 //gfx.cyclesPerLine = 4 * 5 * scd.regs[0x62>>1].w;
411
412 /* start graphics operation */
413 Pico_mcd->s68k_regs[0x58] = 0x80;
414 Pico_mcd->m.state_flags &= ~PCD_ST_S68K_POLL;
415 Pico_mcd->m.s68k_poll_cnt = 0;
416
417 gfx_schedule();
418 }
419}
420
421/* PicoDrive specific */
422#define UPDATE_CYCLES 20000
423
424static void gfx_schedule(void)
425{
426 int w, h, cycles;
427 int y_step;
428
429 w = (Pico_mcd->s68k_regs[0x62] << 8) | Pico_mcd->s68k_regs[0x63];
430 h = (Pico_mcd->s68k_regs[0x64] << 8) | Pico_mcd->s68k_regs[0x65];
431
432 cycles = 5 * w * h;
433 y_step = h;
434 if (cycles > UPDATE_CYCLES)
435 y_step = (UPDATE_CYCLES + 5 * w - 1) / (5 * w);
436
437 gfx.y_step = y_step;
438 pcd_event_schedule_s68k(PCD_EVENT_GFX, 5 * w * y_step);
439}
440
441void gfx_update(unsigned int cycles)
442{
443 int lines, lines_reg;
444 int w;
445
446 if (!(Pico_mcd->s68k_regs[0x58] & 0x80))
447 return;
448
449 w = (Pico_mcd->s68k_regs[0x62] << 8) | Pico_mcd->s68k_regs[0x63];
450 lines = (Pico_mcd->s68k_regs[0x64] << 8) | Pico_mcd->s68k_regs[0x65];
451 lines_reg = lines - gfx.y_step;
452
453 if (lines_reg <= 0) {
454 Pico_mcd->s68k_regs[0x58] = 0;
455 Pico_mcd->s68k_regs[0x64] =
456 Pico_mcd->s68k_regs[0x65] = 0;
457
458 Pico_mcd->m.state_flags &= ~PCD_ST_S68K_POLL;
459 Pico_mcd->m.s68k_poll_cnt = 0;
460 if (Pico_mcd->s68k_regs[0x33] & PCDS_IEN1) {
461 elprintf(EL_INTS|EL_CD, "s68k: gfx_cd irq 1");
462 pcd_irq_s68k(1, 1);
463 }
464 }
465 else {
466 Pico_mcd->s68k_regs[0x64] = lines_reg >> 8;
467 Pico_mcd->s68k_regs[0x65] = lines_reg;
468
469 if (lines > gfx.y_step)
470 lines = gfx.y_step;
471
472 pcd_event_schedule(cycles, PCD_EVENT_GFX, 5 * w * lines);
473 }
474
475 if (PicoIn.opt & POPT_EN_MCD_GFX)
476 {
477 /* render lines */
478 while (lines--)
479 {
480 /* process dots to image buffer */
481 gfx_render(gfx.bufferStart, w);
482
483 /* increment image buffer start index for next line (8 pixels/line) */
484 gfx.bufferStart += 8;
485 }
486 }
487}
488
489// vim:shiftwidth=2:ts=2:expandtab