Hou tae import an eemage
We'r gaun'ae grab this eemage an pit it in the wirkin directory fur the project. Click on it tae dounload the TGA file we'll need.
Whan it's in the projeck files, go intae Makefile an whaur it says TEXTURES, eik jaguar.cry at the end, an the section sud leuk like this.
TEXTURES = c1.cry c2.cry c3.cry u1.cry u2.cry u3.cry l1.cry l2.cry l3.cry \
radar1a.cry radar1b.cry radar1d.cry radar1e.cry turret1b.cry \
winrt.cry winfrnt.cry hood.cry rtfront.cry rtside.cry roof.cry \
gunside.cry guntop.cry wing.cry wingside.cry gunback.cry engfrnt.cry \
engtop.cry engside.cry bottomfr.cry bottom.cry finside.cry fin.cry \
engbot.cry back3.cry jaguar.cry
Farther doun, in FIXDATA, eik -ii jaguar.cry _jagbits at the stairt, as it's ordered fae the biggest tae smawest eemage, an wir eemage is bigger nor ony texturs the demo uises. The code sud leuk like this.
FIXDATA = -ii jaguar.cry _jagbits \
-ii rtside.cry _rtside -ii c1.cry _c1 -ii c2.cry _c2 \
-ii c3.cry _c3 -ii u1.cry _u1 -ii u2.cry _u2 -ii u3.cry _u3 \
-ii l1.cry _l1 -ii l2.cry _l2 -ii l3.cry _l3 \
-ii radar1b.cry _radar1b -ii radar1d.cry _radar1d \
-ii roof.cry _roof -ii wing.cry _wing -ii turret1b.cry _turret1b \
-ii engside.cry _engside -ii rtfront.cry _rtfront \
-ii winfrnt.cry _winfrnt -ii hood.cry _hood -ii back3.cry _back3 \
-ii winrt.cry _winrt -ii engtop.cry _engtop \
-ii wingside.cry _wingside -ii bottom.cry _bottom \
-ii fin.cry _fin -ii guntop.cry _guntop -ii engfrnt.cry _engfrnt \
-ii radar1a.cry _radar1a -ii radar1e.cry _radar1e \
-ii bottomfr.cry _bottomfr -ii gunside.cry _gunside \
-ii finside.cry _finside -ii gunback.cry _gunback \
-ii engbot.cry _engbot \
-ii $(FONTDIR)/clr6x12.jft _usefnt
The seicont bit, _jagbits, is whit the program is gaun'ae refer tae it as. Ye kin name it whitiver ye want.
An that's that! The compiler will convert the TGA tae CRY fur the program. Ye'll juist need tae pynt tae it uisin the name gien tae it.
Hou tae display it in the gemm
Fur this section, we'r muvin ontae demo.c. Tae stairt, we'r needin tae set a coople values. The maist important is the eemage itsel. Whaur aw the variables ur declared at the tap, pit in these lines
#define BMP_WIDTH 128
#define BMP_HEIGHT 16
extern short jagbits[];
Than scroll doun tae the object list arrays. Cawed buf1_olist[] an buf2_olist[]. We hiv 2 as the 3D is dooble-buffered.
Chynge the array sizes an pit in the follaein code atwessh the 2 elements awready thare.
/* Bitmap for sprite */
{{OL_SCALEBITMAP, /* type */
20+(320-BMP_WIDTH)/2, 20+(240-BMP_HEIGHT), /* x, y */
0L, /* link */
(char *)jagbits, /* data */
BMP_HEIGHT, BMP_WIDTH*3/4, BMP_WIDTH/4, /* height, dwidth, iwidth */
4, 1, 0, OL_TRANS, 0, /* depth, pitch, index, flags, firstpix */
OL_SCALE_NONE,OL_SCALE_TRIPLE,0}}, /* scaling stuff */
A lot tae wawkthrou here, lat me break it doun.
OL_SCALEBITMAP - This vailyie represents whit object is bein listit. This kin be a regular OL_BITMAP, OL_SKIP or an array o ither vailyes we willnae titch on here.- The seicont vailyie is the positionin o the sprite. Here we'r pittin it at the centre o the screen. This kin be chynged later.
- The link isnae important tae us here. Lea it as it is.
(char *)jagbits - This is the pynter we declared earlier on the code. This is tellin it whit tae render.- The fift line refers tae the heicht an width o the eemage. These hiv tae match the oreeginal eemage, itherwise it's aither cropped or ither colours in the pallet bleed aroond the eemage.
- The saxt line ur flags tae set fur the eemage. The important yin here is
OL_TRANS, thit makes colour 0 transparent. Color 0 referrin tae bleck.
- The last line is fur scalin. Ye kin chyse atweesh
OL_SCALE_NONE, OL_SCALE_HALF, OL_SCALE_DOUBLE, or OL_SCALE_TRIPLE.
Fur mair information aboot the Object List, this tutorial in Inglis on AtariAge pits it pretty weel!
The resultin code sud leuk like this.
/* object list for first screen */
union olist buf1_olist[3] =
{
{{OL_BITMAP, /* type */
20+(320-OBJWIDTH)/2, 20+(240-OBJHEIGHT), /* x, y */
0L, /* link */
DATA1, /* data */
OBJHEIGHT, OBJWIDTH*3/4, OBJWIDTH/4, /* height, dwidth, iwidth */
4, 3, 0, 0, 0, /* depth, pitch, index, flags, firstpix */
0,0,0}}, /* scaling stuff */
/* Bitmap for sprite */
{{OL_SCALEBITMAP, /* type */
20+(320-BMP_WIDTH)/2, 20+(240-BMP_HEIGHT), /* x, y */
0L, /* link */
(char *)jagbits, /* data */
BMP_HEIGHT, BMP_WIDTH*3/4, BMP_WIDTH/4, /* height, dwidth, iwidth */
4, 1, 0, OL_TRANS, 0, /* depth, pitch, index, flags, firstpix */
OL_SCALE_NONE,OL_SCALE_TRIPLE,0}}, /* scaling stuff */
{{OL_STOP}}
};
/* object list for second screen */
union olist buf2_olist[3] =
{
{{OL_BITMAP, /* type */
20+(320-OBJWIDTH)/2, 20+(240-OBJHEIGHT), /* x, y */
0L, /* link */
DATA2, /* data */
OBJHEIGHT, OBJWIDTH*3/4, OBJWIDTH/4, /* height, dwidth, iwidth */
4, 3, 0, 0, 0, /* depth, pitch, index, flags, firstpix */
0,0,0}}, /* scaling stuff */
/* Bitmap for sprite */
{{OL_SCALEBITMAP, /* type */
20+(320-BMP_WIDTH)/2, 20+(240-BMP_HEIGHT), /* x, y */
0L, /* link */
(char *)jagbits, /* data */
BMP_HEIGHT, BMP_WIDTH*3/4, BMP_WIDTH/4, /* height, dwidth, iwidth */
4, 1, 0, OL_TRANS, 0, /* depth, pitch, index, flags, firstpix */
OL_SCALE_NONE,OL_SCALE_TRIPLE,0}}, /* scaling stuff */
{{OL_STOP}}
};
Ye'll hiv tae eik the sprite ontae baith arrays. Itherwise it will anely render wance ivery 2 frame.
