Annotation of hatari/src/convert/med640x32_spec.c, revision 1.1.1.3

1.1       root        1: /*
                      2:   Hatari - med640x32_spec.c
                      3: 
1.1.1.3 ! root        4:   This file is distributed under the GNU General Public License, version 2
        !             5:   or at your option any later version. Read the file gpl.txt for details.
1.1       root        6: 
                      7:   Screen Conversion, Medium Res Spec512 to 640x32Bit
                      8: */
                      9: 
                     10: static void ConvertMediumRes_640x32Bit_Spec(void)
                     11: {
                     12:        Uint32 *edi, *ebp;
                     13:        Uint32 *esi;
                     14:        Uint32 eax;
                     15:        int y;
                     16: 
                     17:        Spec512_StartFrame();            /* Start frame, track palettes */
                     18: 
                     19:        for (y = STScreenStartHorizLine; y < STScreenEndHorizLine; y++)
                     20:        {
                     21:                eax = STScreenLineOffset[y] + STScreenLeftSkipBytes;  /* Offset for this line + Amount to skip on left hand side */
                     22:                edi = (Uint32 *)((Uint8 *)pSTScreen + eax);        /* ST format screen 4-plane 16 colors */
                     23:                ebp = (Uint32 *)((Uint8 *)pSTScreenCopy + eax);    /* Previous ST format screen */
                     24:                esi = (Uint32 *)pPCScreenDest;                     /* PC format screen */
                     25: 
                     26:                if (HBLPaletteMasks[y] & 0x00030000)               /* Test resolution */
                     27:                        Line_ConvertMediumRes_640x32Bit_Spec(edi, ebp, esi, eax);       /* med res line */
                     28:                else
                     29:                        Line_ConvertLowRes_640x32Bit_Spec(edi, ebp, esi, eax);          /* low res line (double on X) */
                     30: 
                     31:                /* Offset to next line (double on Y) */
                     32:                pPCScreenDest = (((Uint8 *)pPCScreenDest) + PCScreenBytesPerLine * 2);
                     33:        }
                     34: 
                     35:         bScreenContentsChanged = true;
                     36: }
                     37: 
                     38: 
                     39: static void Line_ConvertMediumRes_640x32Bit_Spec(Uint32 *edi, Uint32 *ebp, Uint32 *esi, Uint32 eax)
                     40: {
1.1.1.2   root       41:        Uint32 ebx, ecx;
1.1       root       42:        int x, Screen4BytesPerLine;
                     43:        Uint32 pixelspace[5]; /* Workspace to store pixels to so can print in right order for Spec512 */
                     44: 
                     45:        /* on x86, unaligned access macro touches also
                     46:         * next byte, zero it for code checkers
                     47:         */
                     48:        pixelspace[4] = 0;
                     49: 
                     50:        Spec512_StartScanLine();        /* Build up palettes for every 4 pixels, store in 'ScanLinePalettes' */
                     51: 
                     52:        x = STScreenWidthBytes >> 2;   /* Amount to draw across in 16-pixels (4 bytes) */
                     53:        Screen4BytesPerLine = PCScreenBytesPerLine/4;
                     54: 
                     55:        do  /* x-loop */
                     56:        {
                     57:                /* Do 16 pixels at one time */
                     58:                ebx = *edi;
                     59: 
                     60: 
                     61: #if SDL_BYTEORDER == SDL_BIG_ENDIAN
                     62:                /* Plot in 'right-order' on big endian systems */
                     63:                MED_BUILD_PIXELS_0 ;              /* Generate 'ecx' as pixels [12,13,14,15] */
                     64:                pixelspace[3] = ecx;
                     65:                MED_BUILD_PIXELS_1 ;              /* Generate 'ecx' as pixels [4,5,6,7] */
                     66:                pixelspace[1] = ecx;
                     67:                MED_BUILD_PIXELS_2 ;              /* Generate 'ecx' as pixels [8,9,10,11] */
                     68:                pixelspace[2] = ecx;
                     69:                MED_BUILD_PIXELS_3 ;              /* Generate 'ecx' as pixels [0,1,2,3] */
                     70:                pixelspace[0] = ecx;
                     71: #else
                     72:                /* Plot in 'wrong-order', as ebx is 68000 endian */
                     73:                MED_BUILD_PIXELS_0 ;              /* Generate 'ecx' as pixels [4,5,6,7] */
                     74:                pixelspace[1] = ecx;
                     75:                MED_BUILD_PIXELS_1 ;              /* Generate 'ecx' as pixels [12,13,14,15] */
                     76:                pixelspace[3] = ecx;
                     77:                MED_BUILD_PIXELS_2 ;              /* Generate 'ecx' as pixels [0,1,2,3] */
                     78:                pixelspace[0] = ecx;
                     79:                MED_BUILD_PIXELS_3 ;              /* Generate 'ecx' as pixels [8,9,10,11] */
                     80:                pixelspace[2] = ecx;
                     81: #endif
                     82:                /* And plot, the Spec512 is offset by 1 pixel and works on 'chunks' of 4 pixels */
                     83:                /* So, we plot 1_4_4_4_3 to give 16 pixels, changing palette between */
                     84:                /* (last one is used for first of next 16-pixels) */
                     85:                /* NOTE : In med res, we display 16 pixels in 8 cycles, so palette should be */
                     86:                /* updated every 8 pixels, not every 4 pixels (as in low res) */
                     87:                ecx = pixelspace[0];
                     88:                if (!bScrDoubleY)       { PLOT_SPEC512_LEFT_MED_640_32BIT(0); }
                     89:                else                    { PLOT_SPEC512_LEFT_MED_640_32BIT_DOUBLE_Y(0); }
                     90: //             Spec512_UpdatePaletteSpan();
                     91: 
                     92:                ecx = GET_SPEC512_OFFSET_PIXELS(pixelspace, 1);
                     93:                if (!bScrDoubleY)       { PLOT_SPEC512_MID_MED_640_32BIT(1); }
                     94:                else                    { PLOT_SPEC512_MID_MED_640_32BIT_DOUBLE_Y(1); }
                     95:                Spec512_UpdatePaletteSpan();
                     96: 
                     97:                ecx = GET_SPEC512_OFFSET_PIXELS(pixelspace, 5);
                     98:                if (!bScrDoubleY)       { PLOT_SPEC512_MID_MED_640_32BIT(5); }
                     99:                else                    { PLOT_SPEC512_MID_MED_640_32BIT_DOUBLE_Y(5); }
                    100: //             Spec512_UpdatePaletteSpan();
                    101: 
                    102:                ecx = GET_SPEC512_OFFSET_PIXELS(pixelspace, 9);
                    103:                if (!bScrDoubleY)       { PLOT_SPEC512_MID_MED_640_32BIT(9); }
                    104:                else                    { PLOT_SPEC512_MID_MED_640_32BIT_DOUBLE_Y(9); }
                    105:                Spec512_UpdatePaletteSpan();
                    106: 
                    107:                ecx = GET_SPEC512_OFFSET_FINAL_PIXELS(pixelspace);
                    108:                if (!bScrDoubleY)       { PLOT_SPEC512_END_MED_640_32BIT(13); }
                    109:                else                    { PLOT_SPEC512_END_MED_640_32BIT_DOUBLE_Y(13); }
                    110: 
                    111:                esi += 16;                      /* Next PC pixels */
                    112:                edi += 1;                       /* Next ST pixels */
                    113:                ebp += 1;                       /* Next ST copy pixels */
                    114:        }
                    115:        while (--x);                        /* Loop on X */
                    116: 
                    117:        Spec512_EndScanLine();
                    118: }

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