Figure 8-25 ASCII scroll image

In the system initialization state, the ASCII scroll is configured with 128 cells and 256 colors, and is set to use the normal scroll screen "NBG0". In addition, ASCII scroll data is stored in the following RAM areas.

Character data: 2000H from address 0x25e60000
Map data: 1000H from address 0x25e76000
Palette data: 20H from address 0x25f00000

Listing 8-7 sample_8_10_1: ASCII scroll

/*------------------------------------------------ ----------------------*/
/* Ascii Scroll */
/*------------------------------------------------ ----------------------*/
#include "sgl.h"
#include "ss_scroll.h"

#define NBG1_CEL_ADR VDP2_VRAM_B1
#define NBG1_MAP_ADR ( VDP2_VRAM_B1 + 0x18000 )
#define NBG1_COL_ADR VDP2_COLRAM
#define BACK_COL_ADR ( VDP2_VRAM_A1 + 0x1fffe )

void ss_main(void)
{
	FIXED ascii_posx = SIPOSX , ascii_posy = SIPOSY;

	slInitSystem(TV_320x224,NULL,1);
        slTVOff();
	slPrint("Sample program 8.10.1" , slLocate(9,2));

	slColRAMMode(CRM16_1024);
	slBack1ColSet((void *)BACK_COL_ADR , 0);

	slCharNbg1(COL_TYPE_256 , CHAR_SIZE_1x1);
	slPageNbg1((void *)NBG1_CEL_ADR , 0 , PNB_1WORD|CN_10BIT);
	slPlaneNbg1(PL_SIZE_1x1);
	slMapNbg1((void *)NBG1_MAP_ADR , (void *)NBG1_MAP_ADR , (void *)NBG1_MAP_ADR , (void *)NBG1_MAP_ADR);
	Map2VRAM(ascii_map ,(void *)NBG1_MAP_ADR , 32 , 4 , 0 , 0);

	slScrAutoDisp(NBG0ON | NBG1ON);
	slTVOn();

	while(1) {
		slScrPosNbg1(ascii_posx, ascii_posy);
		ascii_posx += POSX_UP;
		slSynch();
	} 
}

Flow 8-9 sample_8_10_1: ASCII scroll

＜ Figure 8-26 Transparent setting image model＞

The following sample program (Listing 8-8) actually uses the SGL library function "slScrTransparent" to implement transparent color processing for scrolling.

Listing 8-8 sample_8_10_2: Transparent code control

#include "sgl.h"
#include "ss_scroll.h"

#define NBG1_CEL_ADR VDP2_VRAM_B0
#define NBG1_MAP_ADR ( VDP2_VRAM_B0 + 0x10000 )
#define NBG1_COL_ADR ( VDP2_COLRAM + 0x00200 )
#define NBG2_CEL_ADR ( VDP2_VRAM_B1 + 0x02000 )
#define NBG2_MAP_ADR ( VDP2_VRAM_B1 + 0x12000 )
#define NBG2_COL_ADR ( VDP2_COLRAM + 0x00400 )
#define BACK_COL_ADR ( VDP2_VRAM_A1 + 0x1fffe )

void ss_main(void)
{
    Uint16 trns_flg = NBG1ON ;
    FIXED yama_posx = SIPOSX , yama_posy = SIPOSY ;
    FIXED am2_posx = SIPOSX , am2_posy = SIPOSY ;
    
    slInitSystem(TV_320x224,NULL,1);
    slTVOff();
    slPrint("Sample program 8.10.2" , slLocate(9,2)) ;

    slColRAMMode(CRM16_1024);
    slBack1ColSet((void *)BACK_COL_ADR , 0) ;

    slCharNbg1(COL_TYPE_256 , CHAR_SIZE_1x1);
    slPageNbg1((void *)NBG1_CEL_ADR , 0 , PNB_1WORD|CN_10BIT);
    slPlaneNbg1(PL_SIZE_1x1);
    slMapNbg1((void *)NBG1_MAP_ADR , (void *)NBG1_MAP_ADR , (void *)NBG1_MAP_ADR , (void *)NBG1_MAP_ADR);
    Cel2VRAM(am2_cel , (void *)NBG1_CEL_ADR , 16000) ;
    Map2VRAM(am2_map, (void *)NBG1_MAP_ADR, 32, 32, 1, 0);
    Pal2CRAM(am2_pal , (void *)NBG1_COL_ADR , 256) ;

    slCharNbg2(COL_TYPE_256 , CHAR_SIZE_1x1) ;
    slPageNbg2((void *)NBG2_CEL_ADR , 0 , PNB_1WORD|CN_12BIT);
    slPlaneNbg2(PL_SIZE_1x1);
    slMapNbg2((void *)NBG2_MAP_ADR , (void *)NBG2_MAP_ADR , (void *)NBG2_MAP_ADR , (void *)NBG2_MAP_ADR);
    Cel2VRAM(yama_cel , (void *)NBG2_CEL_ADR , 31808) ;
    Map2VRAM(yama_map, (void *)NBG2_MAP_ADR, 32, 16, 2, 256);
    Pal2CRAM(yama_pal , (void *)NBG2_COL_ADR , 256) ;

    slScrPosNbg2(yama_posx, yama_posy);
    slScrPosNbg1(am2_posx, am2_posy);
    slScrTransparent(trns_flg);

    slScrAutoDisp(NBG0ON | NBG1ON | NBG2ON);
    slTVOn();

    while(1)
    {
        if(yama_posx> = (SX + SIPOSX))
        {
            if(trns_flg == NBG1ON)
                trns_flg = 0;
            else
                trns_flg = NBG1ON ;
            yama_posx = SIPOSX;
            slScrTransparent(trns_flg);
        }

	slScrPosNbg2(yama_posx, yama_posy);
	yama_posx += POSX_UP;

	slScrPosNbg1(am2_posx, am2_posy);
	am2_posy += POSY_UP ;

	slSynch();
    } 
}

Flow 8-10 sample_8_10_2: Transparent code control

To perform color calculation processing, you need to take the following steps.

Assign the values shown below that correspond to the color calculation processing control to be used to the parameters.
For details on the parameters, refer to “HARDWARE MANUAL vol.2: VDP2 User's Manual Chapter 12 Color Calculation”.

Figure 8-27 Parameter substitution value (flag) for “slColorCalc”

● ColorCalc substitution value ●
Calculation method: [CC_RATE | CC_ADD] |
Calculation specification image: [CC_TOP | CC_2ND] |
Extended color operation: [CC_EXT] |
Registration surface: [NBG0ON | NBG1ON | NBG2ON | NBG3ON | RBG0ON | LNCLON | SPRON ] |

Add by ratio: Color calculation by specifying the calculation ratio of TOP image and 2ND image (CC_RATE)
Direct addition: Color calculation using simple addition values of TOP image and 2ND image (CC_ADD)

However, if the addition method is used for color calculation, the ratio specification has no meaning.

Flow 8-11 Flow of color calculation processing

To use a line color screen, you need to take the following steps:

If you want to use a single color line color screen, use the function “slLine1ColSet”.

Flow 8-12 Line color screen processing flow