I'm trying to make my triangle drawing code clipped, but I must be doing something wrong becouse the buffer overflows which corrupts some flags of the OS.
ld a, (temp) bit 7, a jr nz, TEndPlot cp 95 jp nc, Cliptemp is the var that contains the x position of the pixel that will be drawn. TEndPlot is a label that is behind the code to plot the pixel, so jumping to here doesn't draw the current pixel. Clip is a label that wen jumped too will stop drawing the current scanline, and prepares for the next one.
bit 7, a jp nz, Clip ld a, (_ty) cp 64 ret nc_ty is the y coordinate of the scanline that will be drawn. Clip stops the current scanline (so nothing will be drawn) and prepares the next one. ret obiously ends the drawing routine.
Everybody who programs z80 or an other low-level programming language has to do a lot of converting between decimal, binary and hexadecimal numbers. This can easily be done by using the windows calculator with normal integers, but when you use signed integers or fixed-point numbers, it gets harder, and takes more time to calculate them. Because I have to do that a lot, I decided to make a tool which can convert all kinds of binary, hexadecimal and decimal numbers to each other, including fixed-point and signed numbers, and I thought this might be useful to other people too, so I decided to distribute it.
It's easy to use it: You just select the base of the input and output, you check if the numbers are signed, select the form (integer or fixed-point) and click the convert key.
For now, the number of bits is ignored, so you may have to use only the last few characters ore add prefix zero's, but it can
Do you find bugs or do you have problems with this program? please post. If you find this program completely useless and you think I shouldn't have distributed it, please post too.
ld hl,(var1) ld de, (var2) ld a, h rla sbc a,a add hl, de ld b, a ld a, (var1+2) adc a, b ld (var1+2), aIt seems to work in some situations, but it also sometimes gives other results. What am I doing wrong?
btw: var1 is the 24bit var, var2 the 16bit one. I haven't fully written this routine, a part of it comes from a load 16bit to 24bit routine from calc84maniac.
I want to calculate the value of a point, based on the position of the point between 4 other points with each an other value. an image to illustrate what I'm trying to say: In this image, there are 4 points with a given value of a and a point between those 4 points which has got an unknown value of a. I now want to know how i can calculate value a of that point, based on the position of that point so that when x=x1 and y=y1, a=a1=1, and when x=x2 and y=y2, a=a2=2, and so on. And when point (x,y) is in the middle of (x1,y1) and (x2,y2), a should be the average of a1 and a2, so a=1.5.
Is there a formula which i can use to interpolate the a value of a point between the a values of the other points?
Back to Cretaceous is a java game which i'm working at with a few friends. The engines are almost done, so now we have to start working at the graphical part. There is still one problem: We can't agree on how the dinosaurs wil look like, so we decided to append a poll. There are three possibilities: - Scales: The dinosaurs will have a scaled skin, which will make them look like giant reptiles. This is how almost everybody thinks abouth dinosaurs. - Feathers: Te dinosaurs will have feathers, which will make them look more like birds. Recent investigation has proved that some small dinosaurs had feathers. Weather the big dinosaurs had feathers is still uncertain. - A mix of the two: small dinosours will have feathers (becouse that's proven) and the big ones will still look like giant reptiles (becouse that's how everybody thinks abouth dinosaurs).
I'm not saying which one I prefer becouse that could have influence on the results, which isn't fair, so please don't ask for it.
Does anybody knows how to draw repeated textures? It would help a lot at my 3D engine, which now can only render wireframe.
I only need to know how it's done, so I can write my own routine.
What I mean with textures: this is a wire frame rectangle rendered by my 3D Engine: I want to draw a sprite between those 4 points. Could someone explain the principle behind this please?
Hi, I am trying to port a simple 3D engine from GML to z80, but I can't get it to work I think my fixed-point math routines aren't doing what they are supposed to do. Can enybody please help with that?
This is what it should do: (speed so low becouse of the recording software. The engine itself renders very efficiently)
And what i got is just an emty screen, while the camera is 5 units away, facing the target, and everything between 1 and 256 units should be visible.
The math currently being unsigned might be one problem, but i couldn't find any 16bit signed fixed-point routines with google.
Spoiler For assembly InitView routine:
InitView: ;call once every frame, before 3DTo2D ;IN: The engine's vars ;OUT: vars are initialised ;DESTROYS: a, bc, de, hl ld bc, (xto) ld de, (xfrom) call SubFP ld (xto), de ld bc, (yto) ld de, (yfrom) call SubFP ld (yto), de ld bc, (zto) ld de, (zfrom) call SubFP ld (zto), de ld bc, (xto) call MulFP push de ;1 ld bc, (yto) call MulFP ld h, d \ ld l, e pop bc ;0 add hl, bc push hl ;1 ld bc, (zto) call MulFP ld h, d \ ld l, e pop de ;0 add hl, de call sqrtFP ld d, h \ ld e, l ld hl, (xto) push de ;1 call DivFP pop de ;0 ld (xto), hl push de ;1 ld hl, (yto) call DivFP pop de ;0 ld (yto), hl ld hl, (zto) call DivFP ld (zto), hl ld bc, (xto) ld hl, (xup) call MulFP push de ;1 ld bc, (yto) ld hl, (yup) call MulFP ld h, d \ ld l, e pop bc ;0 push bc ;1 add hl, bc pop hl ;0 push hl ;1 ld bc, (zto) ld hl, (zup) call MulFP pop hl ;0 add hl, de ld bc, (xto) push hl ;1 call MulFP ld bc, (xup) call SubFP ld (xup), de ld bc, (yto) pop hl ;0 push hl ;1 call MulFP ld bc, (yup) call SubFP ld (yup), de ld bc, (zto) pop hl ;0 call MulFP ld bc, (zup) call SubFP ld (zup), de ld a, (angle) ld b, 40 add a, b call SinA push hl ;1 ld a, (angle) call SinA pop de ;0 call DivFP push hl ;1 ld hl, (xup) ld b, h \ ld c, l call MulFP push de ;2 ld hl, (yup) ld b, h \ ld c, l call MulFP pop hl ;1 add hl, de push hl ;2 ld hl, (zup) ld b, h \ ld c, l call MulFP pop hl ;1 add hl, de call SqrtFP pop bc ;0 call MulFP push de ;1 ld hl, (xup) call divFP ld (xup), hl pop de ;0 push de ;1 ld hl, (yup) call DivFP ld (yup), hl pop de ;0 ld hl, (zup) call DivFP ld (zup), hl ld hl, (yup) ld bc, (zto) call MulFP push de ;1 ld hl, (zup) ld bc, (yto) call MulFP pop hl ;0 call SubFP ld (xcross), de ld hl, (zup) ld bc, (xto) call MulFP push de ;1 ld hl, (xup) ld bc, (zto) call MulFP pop hl ;0 call SubFP ld (ycross), de ld hl, (xup) ld bc, (yto) call MulFP push de ;1 ld hl, (yup) ld bc, (xto) call MulFP pop hl ;0 call SubFP ld (zcross), de ret
Spoiler For assembly 3DTo2D routine:
3DTo2D: ;IN: xpoint, ypoint and zpoint vars ;OUT: screenx and screeny are set to the onscreen coordinates for the point ;Will not work if InitView wasn't called before this routine ;DESTROYS: a, bc, de, hl ld a, 0 ld (valid), a ld bc, (xpoint) ld de, (xfrom) call SubFP ld (xpoint), de ld bc, (ypoint) ld de, (yfrom) call SubFP ld (ypoint), de ld bc, (zpoint) ld de, (zfrom) call SubFP ld (zpoint), de ld hl, (xpoint) ld bc, (xto) call MulFP push de ;1 ld hl, (ypoint) ld bc, (yto) call MulFP pop hl ;0 add hl, de push hl ;1 ld hl, (zpoint) ld bc, (zto) call MulFP pop hl ;0 add hl, de push hl ;1 ld a, l ld c, a ld a, (min_range) ld b, a ld a, c cp b jp c, Invalid ld c, a ld a, (max_range) ld b, a ld a, c cp b jp nc, Invalid ld a, 1 ld (valid), a ld hl, (xpoint) ld bc, (xcross) call MulFP push de ;2 ld hl, (ypoint) ld bc, (ycross) call MulFP pop hl ;1 add hl, de push hl ;2 ld hl, (zpoint) ld bc, (zcross) call MulFP pop hl ;1 add hl, de pop de ;0 push de ;1 call DivFP ld (screenx), hl ld hl, (xpoint) ld bc, (xup) call MulFP push de ;2 LD HL, (ypoint) ld bc, (yup) call MulFP pop hl ;1 add hl, de push hl ;2 ld hl, (zpoint) ld bc, (zup) call MulFP pop hl ;1 add hl, bc pop de ;0 call DivFP ld (screeny), hl ld hl, $0100 ld de, (screenx) add hl, de ld bc, $5F00 call MulFP ld (screenx), de ld hl, $0100 ld de, (screeny) add hl, de ld bc, $4100 call MulFP ld (screeny), de ret Invalid: pop bc ret
Spoiler For assembly math routines:
Mul8b: ;Multiplies 2 8bit numbers ;IN: h and e ;OUT: h * e in hl ;DESTROYS: hl, b, d ld d, 0 ld l, d ld b, 8 _Mul_8b_loop: add hl, hl jr nc, _Mul_8b_skip add hl, de _Mul_8b_skip: djnz _Mul_8b_loop ret
SqrtA: LD (Asqr),A SRL A JR DataOver Asqr: .DB 0 Bsqr: .DB 0 Csqr: .DB 0 DataOver: LD (Bsqr),A LD B,A LD (Csqr),A iterate: LD A,(Bsqr) ld b, a LD a,(Asqr) LD D,A LD E,B divideDbyEreturnA: RL D RLA SUB E JR nc,$+3 ADD A,E LD E,A LD A,D CPL push af ;1 LD a,(Bsqr) ld b, a pop af ;0 ADD A,B SRL A LD (Bsqr),A LD a,(Bsqr) ld b, a LD A,(Csqr) DEC A CP B JR z,done push af ;1 LD (Csqr),a ld b, a pop af ;0 JR iterate done: LD A,(Bsqr) RET
Div16By8: ;divides a 16-bit number by an 8-bit number ;IN: hl and d ;OUT: hl = hl/d, remainder = a ;DESTROYS: a, b, c, d, hl xor a ld b, 16 _D16b8Loop: add hl, hl rla jr c, _D16b8Overflow cp d jr c, _D16b8Skip _D16b8Overflow: sub b inc l _D16b8Skip: djnz _D16b8Loop ret
SubFP: ;substracts 2 16-bit fixed-point numbers ;IN: bc, de ;OUT: bc - de in de ;DESTROYS: a, de ld a, b sub d ld d, a ld a, c sub e ld a, e ret
MulFP: ;Multiplies 2 16bit fixed-point numbers ;IN: hl, bc ;OUT: hl * bc in de ;DESTROYS: hl, bc, de ld e, b push hl ;1 push bc ;2 call Mul8b pop bc ;1 pop hl ;0 push de ;1 ld h, l ld e, c call Mul8b pop hl ;0 ld e, d ld d, l ret
;adding fixed-point numbers: ;load one of the numbers in hl, and the other in an other 16-bit register. ;then, do: add hl, <register>
DivFP: ;IN: hl, de ;OUT: hl = hl / de ld a, h ld h, l ld l, 0 call Div24by16 ret
Div24by16: push hl ;INPUTS: ahl = dividend de = divisor ;1 pop ix ;OUTPUTS: ahl = quotient de = divisor ;0 ld hl,0 ld b,24 _Div24by16loop: add ix,ix rla adc hl,hl jr c,_Div24by16setbit or a sbc hl,de add hl,de jr c,_Div24by16skip _Div24by16setbit: or a sbc hl,de inc ix _Div24by16skip: djnz _Div24by16loop push ix ;1 pop hl ;0 ret
SinA: ;calculates the sine of a as a fixed point number ;IN: a ;OUT: hl = sin(a) LD H, 0 LD L, A LD DE, sine_table ADD HL, DE LD A, (HL) INC HL LD H, (HL) LD L, A RET sine_table: .DW $0000, $0004, $0009, $000D, $0012, $0016, $001B, $001F, $0024 .DW $0028, $002C, $0031, $0035, $003A, $003E, $0042, $0047, $004B .DW $004F, $0053, $0058, $005C, $0060, $0064, $0068, $006C, $0070 .DW $0074, $0078, $007C, $0080, $0084, $0088, $008B, $008F, $0093 .DW $0096, $009A, $009E, $00A1, $00A5, $00A8, $00AB, $00AF, $00B2 .DW $00B5, $00B8, $00BB, $00BE, $00C1, $00C4, $00C7, $00CA, $00CC .DW $00CF, $00D2, $00D4, $00D7, $00D9, $00DB, $00DE, $00E0, $00E2 .DW $00E4, $00E6, $00E8, $00EA, $00EC, $00ED, $00EF, $00F1, $00F2 .DW $00F3, $00F5, $00F6, $00F7, $00F8, $00F9, $00FA, $00FB, $00FC .DW $00FD, $00FE, $00FE, $00FF, $00FF, $00FF, $0100, $0100, $0100
SqrtFP: ;IN: hl ;OUT: hl = sqrt(hl) ld a, h call SqrtA ld h, a ld a, l call SqrtA ld l, a ret
Has enybody got some routines for this on their hard drive (you will get credits for it) or can enybody gelp me with writing my own?
BTW: I added the exe for if enybody wants to try the engine itself (sorry for the ones withouth windows, but GM can only compile exe's)
EDIT: I forgot to say the controls: use z, q, s and d to walk and turn
I just noticed the download links to different OSes of the ti-84 plus I am using Os 2.22, but I found 2.43 and 2.55. So i want to know: has enybody ever tried these OSes, and what are the new features? And how's the compatibility for asm programs?
I've got an other problem: my routine clears the ram, and I don't know why... from 'learn ti83plus asm in 28 Days', i know that ram clears usually appear when you used the stack incorrect, but I've counted all the pushes and pops of the routine, and there were as much pushes as pops. Further is the mem for all the vars stored in the program itself, so it can't be becouse i'm editing mem that shouldn't be edited.
It's just calculating with registers and vars, but i don't know how that can clear the ram.
3DTo2D: ld a, 0 ld (valid), a ld bc, (xpoint) ld de, (xfrom) call SubFP ld (xpoint), de ld bc, (ypoint) ld de, (yfrom) call SubFP ld (ypoint), de ld bc, (zpoint) ld de, (zfrom) call SubFP ld (zpoint), de ld hl, (xpoint) ld bc, (xto) call MulFP push de;1 ld hl, (ypoint) ld bc, (yto) call MulFP pop hl;0 add hl, de push hl;1 ld hl, (zpoint) ld bc, (zto) call MulFP pop hl;0 add hl, de push hl;1 ld a, l ld c, a ld a, (min_range) ld b, a ld a, c cp b jp c, Invalid ld c, a ld a, (max_range) ld b, a ld a, c cp b jp nc, Invalid ld a, 1 ld (valid), a ld hl, (xpoint) ld bc, (xcross) call MulFP push de;2 ld hl, (ypoint) ld bc, (ycross) call MulFP pop hl;1 add hl, de push hl;2 ld hl, (zpoint) ld bc, (zcross) call MulFP pop hl;1 add hl, de pop de;0 push de;1 call DivFP ld (screenx), hl ld hl, (xpoint) ld bc, (xup) call MulFP push de;2 LD HL, (ypoint) ld bc, (yup) call MulFP pop hl;1 add hl, de push hl;2 ld hl, (zpoint) ld bc, (zup) call MulFP pop hl;1 add hl, bc pop de;0 call DivFP ld (screeny), hl ld hl, $0100 ld de, (screenx) add hl, de ld bc, $5F00 call MulFP ld (screenx), de ld hl, $0100 ld de, (screeny) add hl, de ld bc, $4100 call MulFP ld (screeny), de Invalid: ret btw: the commented numbers show the amount of items put on the stack by this routine.
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(speed so low becouse of the recording software. The engine itself renders very efficiently)