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1.1 root 1: /*
1.1.1.7 root 2: Hatari - spec512.c
1.1 root 3:
1.1.1.7 root 4: This file is distributed under the GNU Public License, version 2 or at
5: your option any later version. Read the file gpl.txt for details.
1.1 root 6:
1.1.1.7 root 7: Handle storing of writes to ST palette using clock-cycle counts. We can use
8: this to accurately any form of Spectrum512 style images - even down to the
9: way the screen colours change on decompression routines in menus!
10:
11: As the 68000 has a 4-clock cycle increment we can only change palette every
12: 4 cycles. This means that on one scanline (512 cycles in 50Hz) we have just
13: 512/4=128 places where palette writes can take place. We keep track of this
14: in a table (storing on each scanline and color writes and the cycles on the
15: scanline where they happen). When we draw the screen we simply keep a
16: cycle-count on the line and check this with our table and update the 16-color
17: palette with each change. As the table is already ordered this makes things
18: very simple. Speed is a problem, though, as the palette can change once every
19: 4 pixels - that's a lot of processing.
1.1 root 20: */
1.1.1.10 root 21:
22:
23: /* 2008/01/12 [NP] In Spec512_StoreCyclePalette, don't use Cycles_GetCounterOnWriteAccess */
24: /* as it doesn't support movem for example. Use Cycles_GetCounter with */
25: /* an average correction of 8 cycles (this should be fixed). */
26: /* In Spec512_StartScanLine, better handling of SCREENBYTES_LEFT when */
27: /* border are present. Better alignement of pixel and color when left */
28: /* border is removed (Rotofull in Nostalgia Demo, When Colors Are Going */
29: /* Bang Bang by DF in Punish Your Machine). */
30: /* 2008/01/13 [NP] In Spec512_StoreCyclePalette, if a movem was used to access several */
31: /* color regs just before the end of a line, the value for nHorPos was not */
32: /* checked and could take values >= 512, which means some colors in the */
33: /* palette were overwritten next time colors were stored on the next line */
34: /* and the palette was not set correctly, especially in the bottom of the */
35: /* screen (Decade Demo Main Menu, Punish Your Machine Main Menu, ULM */
36: /* Hidden Screen in Oh Crickey...). */
37: /* 2008/01/13 [NP] One line should contain 512/4 + 1 colors slots, not 512/4. Else, if */
38: /* a program manages to change colors every 4 cycles, the '-1' terminator */
39: /* added by Spec512_StartFrame will in fact be written on cycle 0 in the */
40: /* next line (this is theorical, practically no program changes the color */
41: /* 128 times per line). */
42: /* Use nCyclesPerLine instead of 512 to check if nHorPos is too big and if */
43: /* the colors must be stored on the next line when freq is 50 or 60Hz */
44: /* (readme.prg by TEX (in 1987)) */
45: /* 2008/01/24 [NP] In Spec512_StartScanLine, use different values for LineStartCycle when */
46: /* running in 50 Hz or 60 Hz (TEX Spectrum Slideshow in 60 Hz). */
1.1.1.13 root 47: /* 2008/12/14 [NP] In Spec512_StoreCyclePalette, instead of approximating write position */
48: /* by Cycles_GetCounter+8, we use different cases for movem, .l acces and */
49: /* .w acces (similar to cycles.c). This gives correct results when using */
50: /* "move.w d0,(a0) or move.w (a0)+,(a1)+" for example, which were shifted */
51: /* 8 or 4 pixels too late. Calibration was made using a custom program to */
52: /* compare the results with a real STF in different cases (fix Froggies */
53: /* Over The Fence Main Menu). */
1.1.1.14 root 54: /* 2008/12/21 [NP] Use BusMode to adjust Cycles_GetCounterOnReadAccess and */
55: /* Cycles_GetCounterOnWriteAccess depending on who is owning the */
56: /* bus (cpu, blitter). */
57: /* 2009/07/28 [NP] Use different timings for movem.l and movem.w */
1.1.1.10 root 58:
59:
1.1.1.14 root 60: const char Spec512_fileid[] = "Hatari spec512.c : " __DATE__ " " __TIME__;
1.1 root 61:
1.1.1.4 root 62: #include <SDL_byteorder.h>
63:
1.1 root 64: #include "main.h"
1.1.1.9 root 65: #include "cycles.h"
1.1.1.15 root 66: #include "cycInt.h"
1.1.1.10 root 67: #include "m68000.h"
1.1.1.13 root 68: #include "ioMem.h"
1.1 root 69: #include "screen.h"
70: #include "spec512.h"
71: #include "video.h"
1.1.1.10 root 72: #include "configuration.h"
1.1.1.12 root 73:
1.1 root 74:
1.1.1.9 root 75: /* As 68000 clock multiple of 4 this mean we can only write to the palette this many time per scanline */
1.1.1.10 root 76: #define MAX_CYCLEPALETTES_PERLINE ((512/4) + 1) /* +1 for the '-1' added as a line's terminator */
1.1.1.9 root 77:
78: /* Store writes to palette by cycles per scan line, colour and index in ST */
79: typedef struct
80: {
1.1.1.10 root 81: int LineCycles; /* Number of cycles into line (MUST be div by 4) */
82: Uint16 Colour; /* ST Colour value */
83: Uint16 Index; /* Index into ST palette (0...15) */
84: }
85: CYCLEPALETTE;
1.1.1.2 root 86:
1.1.1.8 root 87: /* 314k; 1024-bytes per line */
1.1.1.9 root 88: static CYCLEPALETTE CyclePalettes[(MAX_SCANLINES_PER_FRAME+1)*MAX_CYCLEPALETTES_PERLINE];
89: static CYCLEPALETTE *pCyclePalette;
90: static int nCyclePalettes[(MAX_SCANLINES_PER_FRAME+1)]; /* Number of entries in above table for each scanline */
1.1.1.10 root 91: static int nPalettesAccesses; /* Number of times accessed palette registers */
1.1.1.8 root 92: static Uint16 CycleColour;
93: static int CycleColourIndex;
94: static int nScanLine, ScanLineCycleCount;
1.1.1.12 root 95: static bool bIsSpec512Display;
1.1 root 96:
1.1.1.4 root 97: #if SDL_BYTEORDER == SDL_BIG_ENDIAN
1.1.1.10 root 98: static const int STRGBPalEndianTable[16] =
99: {
100: 0,2,1,3,8,10,9,11,4,6,5,7,12,14,13,15
101: };
1.1.1.4 root 102: #endif
103:
1.1.1.2 root 104:
105: /*-----------------------------------------------------------------------*/
1.1.1.10 root 106: /**
1.1.1.16! root 107: * Return true if this frame is a Spectrum 512 style image (can be low/med
! 108: * res mix).
1.1.1.10 root 109: */
1.1.1.12 root 110: bool Spec512_IsImage(void)
1.1 root 111: {
1.1.1.16! root 112: /* Spec512 mode was triggered in low or med res ? */
! 113: if (bIsSpec512Display)
1.1.1.14 root 114: return true;
1.1 root 115:
1.1.1.14 root 116: return false;
1.1 root 117: }
118:
1.1.1.2 root 119:
120: /*-----------------------------------------------------------------------*/
1.1.1.10 root 121: /**
1.1.1.14 root 122: * We store every palette access in a table to perform Spectrum 512 color
123: * effects. This is cleared on each VBL.
1.1.1.10 root 124: */
1.1 root 125: void Spec512_StartVBL(void)
126: {
1.1.1.10 root 127: /* Clear number of cycle palettes on each frame */
128: memset(nCyclePalettes, 0x0, sizeof(nCyclePalettes));
129:
1.1.1.14 root 130: /* Clear number of times accessed on entry in palette (used to check if
131: * it is true Spectrum 512 image) */
1.1.1.10 root 132: nPalettesAccesses = 0;
133:
134: /* Set as not Spectrum 512 displayed image */
1.1.1.14 root 135: bIsSpec512Display = false;
1.1 root 136: }
137:
1.1.1.2 root 138:
139: /*-----------------------------------------------------------------------*/
1.1.1.10 root 140: /**
141: * Store color into table 'CyclePalettes[]' for screen conversion according
142: * to cycles into frame.
143: */
1.1.1.8 root 144: void Spec512_StoreCyclePalette(Uint16 col, Uint32 addr)
1.1 root 145: {
1.1.1.10 root 146: CYCLEPALETTE *pTmpCyclePalette;
147: int FrameCycles, ScanLine, nHorPos;
1.1 root 148:
1.1.1.10 root 149: if (!ConfigureParams.Screen.nSpec512Threshold)
150: return;
1.1.1.4 root 151:
1.1.1.10 root 152: CycleColour = col;
153: CycleColourIndex = (addr-0xff8240)>>1;
1.1 root 154:
1.1.1.10 root 155: /* Find number of cycles into frame */
156: /* FIXME [NP] We should use Cycles_GetCounterOnWriteAccess, but it wouldn't */
157: /* work when using multiple accesses instructions like move.l or movem */
158: /* To correct this, assume a delay of 8 cycles (should give a good approximation */
159: /* of a move.w or movem.l for example) */
160: // FrameCycles = Cycles_GetCounterOnWriteAccess(CYCLES_COUNTER_VIDEO);
1.1.1.13 root 161: if ( BusMode == BUS_MODE_BLITTER )
162: {
163: FrameCycles = Cycles_GetCounterOnWriteAccess(CYCLES_COUNTER_VIDEO);
164: }
165: else /* BUS_MODE_CPU */
166: {
167: #ifdef OLD_CYC_PAL
168: FrameCycles = Cycles_GetCounter(CYCLES_COUNTER_VIDEO) + 8;
169: #else
170: if ( OpcodeFamily == i_MVMLE )
171: {
1.1.1.14 root 172: // FrameCycles = Cycles_GetCounter(CYCLES_COUNTER_VIDEO) + 8;
173: FrameCycles = Cycles_GetCounter(CYCLES_COUNTER_VIDEO)
174: + (CurrentInstrCycles & ~3);
175: if (nIoMemAccessSize == SIZE_LONG) /* long access */
176: FrameCycles -= 0;
177: else /* word access */
178: FrameCycles -= 4;
179: }
180: else
181: {
182: FrameCycles = Cycles_GetCounter(CYCLES_COUNTER_VIDEO)
183: + (CurrentInstrCycles & ~3);
184: if (nIoMemAccessSize == SIZE_LONG) /* long access */
185: FrameCycles -= 8;
186: else /* word/byte access */
187: FrameCycles -= 4;
1.1.1.13 root 188: }
189: #endif
190: }
1.1.1.10 root 191:
192:
193: /* Find scan line we are currently on and get index into cycle-palette table */
1.1.1.14 root 194: Video_ConvertPosition ( FrameCycles , &ScanLine , &nHorPos );
1.1.1.11 root 195:
196: if (ScanLine > MAX_SCANLINES_PER_FRAME)
197: return;
198:
1.1.1.10 root 199: pTmpCyclePalette = &CyclePalettes[ (ScanLine*MAX_CYCLEPALETTES_PERLINE) + nCyclePalettes[ScanLine] ];
200:
201:
202: /* Do we have a previous entry at the same cycles? If so, 68000 have used a 'move.l' instruction so stagger writes */
203: if (nCyclePalettes[ScanLine] > 0)
204: {
205: /* In case the ST uses a move.l or a movem.l to update colors, we need
206: * to add at least 4 cycles between each color: */
207: if ((pTmpCyclePalette-1)->LineCycles >= nHorPos)
208: nHorPos = (pTmpCyclePalette-1)->LineCycles + 4;
209:
210: if ( nHorPos >= nCyclesPerLine ) /* end of line reached, continue on the next line */
211: {
212: ScanLine++;
213: pTmpCyclePalette = &CyclePalettes[ (ScanLine*MAX_CYCLEPALETTES_PERLINE) + nCyclePalettes[ScanLine] ];
214: nHorPos = nCyclePalettes[ScanLine] * 4; /* 4 cycles per access */
215: }
216: }
217:
218: /* Store palette access */
219: pTmpCyclePalette->LineCycles = nHorPos; /* Cycles into scanline */
220: pTmpCyclePalette->Colour = CycleColour; /* Store ST/STe color RGB */
221: pTmpCyclePalette->Index = CycleColourIndex; /* And index (0...15) */
222:
1.1.1.14 root 223: if ( 0 && LOG_TRACE_LEVEL(TRACE_VIDEO_COLOR))
1.1.1.10 root 224: {
1.1.1.14 root 225: int FrameCycles, HblCounterVideo, LineCycles;
226:
227: Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
228: LOG_TRACE_PRINT("spec store col line %d cyc=%d col=%x idx=%d video_cyc=%d %d@%d pc=%x instr_cyc=%d\n",
229: ScanLine, nHorPos, CycleColour, CycleColourIndex, FrameCycles,
230: LineCycles, HblCounterVideo, M68000_GetPC(), CurrentInstrCycles);
1.1.1.10 root 231: }
232:
233: /* Increment count (this can never overflow as you cannot write to the palette more than 'MAX_CYCLEPALETTES_PERLINE-1' times per scanline) */
234: nCyclePalettes[ScanLine]++;
235:
236: /* Check if program wrote to palette registers multiple times on a frame. */
237: /* If so it must be using a spec512 image or some kind of color cycling. */
238: nPalettesAccesses++;
239: if (nPalettesAccesses >= ConfigureParams.Screen.nSpec512Threshold)
240: {
1.1.1.14 root 241: bIsSpec512Display = true;
1.1.1.10 root 242: }
1.1 root 243: }
244:
1.1.1.2 root 245:
246: /*-----------------------------------------------------------------------*/
1.1.1.10 root 247: /**
248: * Begin palette calculation for Spectrum 512 style images,
249: */
1.1 root 250: void Spec512_StartFrame(void)
251: {
1.1.1.10 root 252: int i;
1.1 root 253:
1.1.1.10 root 254: /* Set so screen gets full-update when returns from Spectrum 512 display */
255: Screen_SetFullUpdate();
1.1 root 256:
1.1.1.10 root 257: /* Set terminators on each line, so when scan during conversion we know when to stop */
258: for (i = 0; i < (nScanlinesPerFrame+1); i++)
259: {
260: pCyclePalette = &CyclePalettes[ (i*MAX_CYCLEPALETTES_PERLINE) + nCyclePalettes[i] ];
261: pCyclePalette->LineCycles = -1; /* Term */
262: }
263:
1.1.1.12 root 264: /* Copy first line palette, kept in 'HBLPalettes' and store to 'STRGBPalette' */
265: for (i = 0; i < 16; i++)
266: {
1.1.1.4 root 267: #if SDL_BYTEORDER == SDL_BIG_ENDIAN
1.1.1.12 root 268: STRGBPalette[STRGBPalEndianTable[i]] = ST2RGB[pHBLPalettes[i]];
1.1.1.4 root 269: #else
1.1.1.12 root 270: STRGBPalette[i] = ST2RGB[pHBLPalettes[i]];
1.1.1.4 root 271: #endif
1.1.1.12 root 272: }
1.1 root 273:
1.1.1.10 root 274: /* Ready for first call to 'Spec512_ScanLine' */
275: nScanLine = 0;
276: if (OverscanMode & OVERSCANMODE_TOP)
277: nScanLine += OVERSCAN_TOP;
278:
279: /* Skip to first line(where start to draw screen from) */
280: for (i = 0; i < (STScreenStartHorizLine+(nStartHBL-OVERSCAN_TOP)); i++)
281: Spec512_ScanWholeLine();
1.1 root 282: }
283:
1.1.1.2 root 284:
285: /*-----------------------------------------------------------------------*/
1.1.1.10 root 286: /**
287: * Scan whole line and build up palette - need to do this so when get to screen line we have
288: * the correct 16 colours set
289: */
1.1 root 290: void Spec512_ScanWholeLine(void)
291: {
1.1.1.10 root 292: /* Store pointer to line of palette cycle writes */
293: pCyclePalette = &CyclePalettes[nScanLine*MAX_CYCLEPALETTES_PERLINE];
294: /* Ready for next scan line */
295: nScanLine++;
296:
297: /* Update palette entries until we reach start of displayed screen */
298: ScanLineCycleCount = 0;
299: Spec512_EndScanLine(); /* Read whole line of palettes and update 'STRGBPalette' */
1.1 root 300: }
301:
1.1.1.2 root 302:
303: /*-----------------------------------------------------------------------*/
1.1.1.10 root 304: /**
305: * Build up palette for this scan line and store in 'ScanLinePalettes'
306: */
1.1 root 307: void Spec512_StartScanLine(void)
308: {
1.1.1.10 root 309: int i;
310: int LineStartCycle;
1.1 root 311:
1.1.1.10 root 312: /* Store pointer to line of palette cycle writes */
313: pCyclePalette = &CyclePalettes[nScanLine*MAX_CYCLEPALETTES_PERLINE];
314: /* Ready for next scan line */
315: nScanLine++;
316:
317: if ( nScanlinesPerFrame == SCANLINES_PER_FRAME_50HZ )
318: LineStartCycle = LINE_START_CYCLE_50; /* The screen was 50 Hz */
319: else
320: LineStartCycle = LINE_START_CYCLE_60; /* The screen was 60 Hz */
321:
322: /* Update palette entries until we reach start of displayed screen */
323: ScanLineCycleCount = 0;
324: // for(i=0; i<((SCREEN_START_CYCLE-16)/4); i++) /* This '16' is as we've already added in the 'move' instruction timing */
1.1.1.13 root 325: #ifdef OLD_CYC_PAL
1.1.1.10 root 326: for (i=0; i<((LineStartCycle-SCREENBYTES_LEFT*2)/4 + 6); i++) /* [NP] '6' is required to align pixels and colors */
1.1.1.13 root 327: #else
328: for (i=0; i<((LineStartCycle-SCREENBYTES_LEFT*2)/4 + 7); i++) /* [NP] '7' is required to align pixels and colors */
329: #endif
1.1.1.10 root 330: Spec512_UpdatePaletteSpan(); /* Update palette for this 4-cycle period */
331:
332: /* And skip for left border is not using overscan display to user */
333: for (i=0; i<(STScreenLeftSkipBytes/2); i++) /* Eg, 16 bytes = 32 pixels or 8 palette periods */
334: Spec512_UpdatePaletteSpan();
1.1 root 335: }
336:
1.1.1.2 root 337:
338: /*-----------------------------------------------------------------------*/
1.1.1.10 root 339: /**
340: * Run to end of scan line looking up palettes so 'STRGBPalette' is up-to-date
341: */
1.1 root 342: void Spec512_EndScanLine(void)
343: {
1.1.1.10 root 344: /* Continue to reads palette until complete so have correct version for next line */
345: while (ScanLineCycleCount < nCyclesPerLine)
346: Spec512_UpdatePaletteSpan();
1.1 root 347: }
348:
1.1.1.2 root 349:
350: /*-----------------------------------------------------------------------*/
1.1.1.10 root 351: /**
352: * Update palette for 4-pixels span, storing to 'STRGBPalette'
353: */
1.1 root 354: void Spec512_UpdatePaletteSpan(void)
355: {
1.1.1.10 root 356: if (pCyclePalette->LineCycles == ScanLineCycleCount)
357: {
358: /* Need to update palette with new entry */
1.1.1.4 root 359: #if SDL_BYTEORDER == SDL_BIG_ENDIAN
1.1.1.10 root 360: STRGBPalette[STRGBPalEndianTable[pCyclePalette->Index]] = ST2RGB[pCyclePalette->Colour];
1.1.1.4 root 361: #else
1.1.1.10 root 362: STRGBPalette[pCyclePalette->Index] = ST2RGB[pCyclePalette->Colour];
1.1.1.16! root 363: //fprintf ( stderr , "upd spec cyc %d %x %x\n" , ScanLineCycleCount , pCyclePalette->Index , pCyclePalette->Colour );
1.1.1.4 root 364: #endif
1.1.1.10 root 365: pCyclePalette += 1;
366: }
367: ScanLineCycleCount += 4; /* Next 4 cycles */
1.1 root 368: }
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