source: buchla-68k/orig/RAM/SCADV.C@ c79db87

Last change on this file since c79db87 was 3ae31e9, checked in by Thomas Lopatic <thomas@…>, 8 years ago

Imported original source code.
  • Property mode set to 100755
File size: 6.2 KB
Line 
1/*
2 =============================================================================
3 scadv.c -- MIDAS-VII -- move score 1 frame forward or backward
4 Version 48 -- 1989-12-19 -- D.N. Lynx Crowe
5 =============================================================================
6*/
7
8#undef DEBUGGER /* define to enable debug trace */
9
10#undef TRACEIT /* define to enable step by step trace */
11
12#include "debug.h"
13
14#include "stddefs.h"
15#include "hwdefs.h"
16#include "graphdef.h"
17#include "score.h"
18#include "vsdd.h"
19
20#include "midas.h"
21#include "scdsp.h"
22
23#ifdef TRACEIT
24short tracesw;
25#endif
26
27/* variables defined elsewhere */
28
29extern unsigned *consl;
30extern unsigned *cursl;
31extern unsigned *nxtsl;
32extern unsigned *prvsl;
33extern unsigned *saddr;
34
35extern unsigned scrl;
36extern unsigned vi_sadr;
37extern unsigned vi_scrl;
38
39extern short ctrsw;
40extern short ndisp;
41extern short sbase;
42extern short sd;
43extern short soffset;
44
45extern struct gdsel *gdstbc[];
46extern struct gdsel *gdstbn[];
47extern struct gdsel *gdstbp[];
48
49/*
50
51*/
52
53/* initialized stuff */
54
55short nbmoff = 3;
56short wrdoff = 3;
57
58short nbmasks[4] = { /* nybble masks */
59
60 0x000F,
61 0x00F0,
62 0x0F00,
63 0xF000
64};
65
66/*
67
68*/
69
70/*
71 =============================================================================
72 sc_adv() -- advance the score display 1 frame
73
74 Note that the score display actually only moves every other frame,
75 due to VSDD limitations, but it moves 2 pixels.
76 =============================================================================
77*/
78
79sc_adv()
80{
81 register short masksl, maskpx, i;
82 register unsigned sword;
83 register long tl;
84 register unsigned *optr, *pptr, *fsl;
85 unsigned *qptr;
86 unsigned pscrl;
87
88 DB_ENTR("sc_adv");
89
90#ifdef TRACEIT
91 if (tracesw) {
92
93 printf("scadv ----------------------\n");
94 SEctrl();
95 }
96
97 if (tracesw & 0x0001) {
98
99 SCslice();
100 }
101#endif
102
103 if (v_regs[5] & 0x0180) /* make sure we're in bank 0 */
104 vbank(0);
105
106 tl = 128L; /* setup VSDD line increment */
107
108 DB_CMNT("sc_adv - center ucslice");
109
110 ucslice(); /* update the center slice */
111
112/*
113
114*/
115 /* see if it's time to update VRAM from edges */
116
117 if ((ndisp EQ 2) AND (soffset EQ ((sd EQ D_BAK) ? 0 : 3))) {
118
119 if (sd EQ D_BAK) { /* set source and target pointers */
120
121 fsl = prvsl;
122 optr = saddr + wrdoff;
123
124 } else {
125
126 fsl = nxtsl;
127 optr = saddr + tl;
128 }
129
130 if (sbase > 28544) { /* possible double update ? */
131
132 /* set target pointer #2 */
133
134 pptr = saddr - ((sd EQ D_BAK) ? 28542L : 28545L);
135
136 if (sbase < 28672) { /* double update - right and left */
137
138 DB_CMNT("sc_adv - double update");
139
140 for (i = 224; i--; ) {
141
142 sword = *fsl++; /* copy a slice word to the VSDD */
143 *optr = sword;
144 *pptr = sword;
145 optr += tl; /* advance the VSDD pointers */
146 pptr += tl;
147 }
148
149 } else { /* single update - left */
150
151 DB_CMNT("sc_adv - left update");
152
153 for (i = 224; i--; ) {
154
155 *pptr = *fsl++; /* copy a slice word to the VSDD */
156 pptr += tl; /* advance the VSDD pointers */
157 }
158 }
159/*
160
161*/
162 } else { /* single update - right */
163
164 DB_CMNT("sc_adv - right update");
165
166 for (i = 224; i--; ) {
167
168 *optr = *fsl++; /* copy a slice word to the VSDD */
169 optr += tl; /* advance the VSDD pointers */
170 }
171 }
172
173 optr = nxtsl; /* refresh update slices from constant slice */
174 pptr = cursl;
175 qptr = prvsl;
176 fsl = consl;
177
178 for (i = 224; i--; ) {
179
180 sword = *fsl++;
181 *optr++ = sword;
182 *pptr++ = sword;
183 *qptr++ = sword;
184 }
185
186 DB_CMNT("sc_adv - slices refreshed");
187 }
188
189/*
190
191*/
192 if (sd EQ D_FWD) {
193
194 if (++soffset > 3) { /* advance scroll counter */
195
196 soffset = 0; /* roll over scroll counter */
197 ++saddr; /* advance VRAM address */
198
199 if (++sbase > 28672) { /* advance scroll offset */
200
201 saddr = v_score; /* roll over VRAM address */
202 sbase = 0; /* roll over scroll offset */
203 }
204 }
205
206 } else {
207
208 if (--soffset < 0) { /* decrement scroll counter */
209
210 soffset = 3; /* roll over scroll counter */
211 --saddr; /* advance VRAM address */
212
213 if (--sbase < 0) { /* advance scroll offset */
214
215 saddr = v_score + 28672L; /* roll over VRAM address */
216 sbase = 28672; /* roll over scroll offset */
217 }
218 }
219 }
220/*
221
222*/
223 pscrl = scrl; /* save old scrl value */
224
225 DB_CMNT("sc_adv - edge uslice");
226
227 maskpx = nbmasks[soffset]; /* setup source pixel mask */
228 masksl = ~maskpx; /* setup target pixel mask */
229
230 uslice(prvsl, maskpx, masksl, gdstbp); /* update left edge */
231
232 uslice(nxtsl, maskpx, masksl, gdstbn); /* update right edge */
233
234 scrl = 0x8000 | ((soffset >> 1) ^ 0x0001);
235
236 /* only update VSDD registers if score is up and scrl changed */
237
238 if ((ndisp EQ 2) AND (scrl NE pscrl)) {
239
240 sword = (unsigned)((char *)saddr >> 1);
241
242 setipl(VID_DI); /* disable video interrupts */
243
244 vi_scrl = scrl;
245 vi_sadr = sword;
246
247 setipl(VID_EI); /* enable video interrupts */
248 }
249
250 ctrsw = FALSE;
251
252#ifdef TRACEIT
253 if (tracesw & 0x0002) {
254
255 SCslice();
256 }
257#endif
258
259 DB_EXIT("sc_adv");
260}
261
262/*
263
264*/
265
266/*
267 =============================================================================
268 scupd() -- update the center slice without scrolling
269 =============================================================================
270*/
271
272scupd()
273{
274 register short masksl, maskpx, i;
275 register unsigned sword;
276 register long tl;
277 register unsigned *optr, *qptr, *fsl;
278 short soff;
279
280 DB_ENTR("scupd");
281
282 if (v_regs[5] & 0x0180) /* make sure we're in bank 0 */
283 vbank(0);
284
285 soff = (nbmoff + soffset) & 3; /* calculate offset to use */
286 maskpx = nbmasks[(2 + soff) & 3]; /* setup source pixel mask */
287 masksl = ~maskpx; /* setup target pixel mask */
288 tl = 128L; /* setup VSDD line increment */
289
290 /* update VRAM, if it's time */
291
292 if (cslice(cursl, maskpx, masksl, gdstbc) AND (ndisp EQ 2)) {
293
294 DB_CMNT("scupd - center write ...");
295
296 fsl = cursl;
297 optr = saddr + ((soff > 1) ? 64L : 63L);
298 qptr = consl;
299
300 for (i = 224; i--; ) {
301
302 if (sword = maskpx & *fsl)
303 *optr = (*optr & masksl) | sword;
304
305 *fsl++ = *qptr++; /* clean up the slice */
306 optr += tl;
307 }
308
309 DB_CMNT("scupd - center written");
310 }
311
312 ctrsw = FALSE;
313}
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