PLOT and DRAW with APi

[Zlatko Vid]

Hello Charles & ALL

I am trying to make classic PLOT and DRAW functions using api calls

MoveToEx hdc, x,y ,lppt

and

LineTo hdc,x1,y1

and i made search all over net but nothing concrete
i just found this small example in C ...so
how this can be translated to Oxygenbasic...
any hint?

Code Select Expand

static POINT ptPrevious = { 0,0 };
static bool flag = false;
Vertex temp;
...
case WM_LBUTTONDOWN:
        HDC hdc = GetDC(hWnd);
        POINTS clickPoint = MAKEPOINTS(lParam);
        if (flag == false) {
            ptPrevious.x = clickPoint.x;
            ptPrevious.y = clickPoint.y;
            flag = true;
        }
        //store the point in connectLines
        temp.SetX(clickPoint.x);
        temp.SetY(clickPoint.y);
        connectLines.push_back(temp);

        MoveToEx(hdc, ptPrevious.x, ptPrevious.y, NULL);
        LineTo(hdc, LOWORD(lParam), HIWORD(lParam));

        //record previous point
        ptPrevious.x = clickPoint.x;
        ptPrevious.y = clickPoint.y;

        ReleaseDC(hWnd, hdc);
        break;

[Charles Pegge]

Hi Aurel,

uses corewin includes all the GDI functions. Then it's much the same as your C snippet.  But it is better to store all the plots into an array, so you can do screen refreshes, and save/reload the plot.

[Zlatko Vid]

Hi Charles

I agree that would be nice to store data in array

[Theo Gottwald]

if you like speed, make these commands in ASM.
You so know know ASM?
Ask ChatGPT he can give you the ASM Code for all these commands.
I have tried, it works. Ok, it may need small corrections here and there  but generally its fine.

Code Select Expand


section .data

; Define the width and height of the image
width   db 100
height  db 100

; Define the starting x and y position of the line
x_start db 50
y_start db 50

; Define the angle and length of the line
angle   dd 3.14159265358979 / 4
length  dd 50

section .bss

; Reserve space for the image buffer
image_buffer resb width * height * 3

section .text

; The main function
global _start

_start:
    ; Load the angle and length into the x87 FPU
    fld angle
    fsin
    fstp [sin_result]
    fld angle
    fcos
    fstp [cos_result]

    ; Calculate the end position of the line
    mov eax, [length]
    fild eax
    fmul dword [sin_result]
    fistp [y_end]
    mov eax, [length]
    fild eax
    fmul dword [cos_result]
    fistp [x_end]

    ; Add the starting position to the end position to get the final end position
    add [x_end], [x_start]
    add [y_end], [y_start]

    ; Calculate the delta x and y
    mov eax, [x_end]
    sub eax, [x_start]
    mov [delta_x], eax
    mov eax, [y_end]
    sub eax, [y_start]
    mov [delta_y], eax

    ; Calculate the address of the starting pixel
    mov ebx, image_buffer
    add ebx, y_start * width * 3
    add ebx, x_start * 3

    ; Draw the line
    mov eax, [delta_x]
    mov edx, [delta_y]
    cmp eax, 0
    jge .x_positive
    neg eax
    .x_positive:
    cmp edx, 0
    jge



[Zlatko Vid]

if you like speed, make these commands in ASM

Oh ..you don't know ?
o2 basic and o2 asm run at same speed ..i TESTED

[Theo Gottwald]

But in O2 you still need to handcode it yourself :-)