Club Amiga de Montreal - CAM/CAM_CD_1.iso/files/038.lha/sc.c

C/C++ Source or Header | 1987-05-16 | 4.7 KB | 198 lines

#include:intuition/miscellaneous.g
#include:intuition/screen.g
#include:intuition/window.g
#include:intuition/intuitext.g
#include:intuition/requester.g
#include:graphics/gfx.g
#include:graphics/view.g
#include:graphics/rastport.g
#include:libraries/dos.g

/*
 * sc.d - fractalish terrain generator.
 *
 *    Date:      March 5, 1987 (original version sometime in 1985)
 *    Author:      Chris Gray
 *    Language: Draco
 *    System:      Amiga
 */

/*
 * The nature of the terrain can be changed by playing with the numbers
 * in 'Range'. If you change SIZE, you must also change the number of
 * values given for 'Range'. The created terrain with SIZE = 8 is 256 pixels
 * by 256 pixels, which doesn't fit on a non-interlaced screen, so only the
 * top 200 pixels are displayed. The terrain is a torus, i.e. wraps around
 * both vertically and horizontally.
 */

/*
 * Feel free to use this algorithm in any games you write, so long as you
 * give me credit for it. (I THINK I invented it, since I've never heard of
 * anything similar, and other programs I've seen use much slower methods.)
 */

uint
    SIZE = 8,
    COUNT = 1 << SIZE,

    SCREEN_WIDTH = 320,
    SCREEN_HEIGHT = 200,
    SCREEN_DEPTH = 5,
    COLOURS = 1 << SCREEN_DEPTH,
    WINDOW_WIDTH = if COUNT < SCREEN_WIDTH then COUNT else SCREEN_WIDTH fi,
    WINDOW_HEIGHT = if COUNT < SCREEN_HEIGHT then COUNT else SCREEN_HEIGHT fi;

[SIZE] uint Range = (32, 32, 32, 22, 14, 8, 4, 2);

[COLOURS] uint ColourMap = (
    0x00f, 0x050, 0x070, 0x0a0, 0x0c0, 0x0e0, 0x4f4, 0x8f8,
    0xdf0, 0xff0, 0xfd0, 0xfb0, 0xf90, 0xf70, 0xe50, 0xe33,
    0xe11, 0xf01, 0xf03, 0xf05, 0xf07, 0xf09, 0xf0b, 0xf0d,
    0xf1f, 0xf3f, 0xf5f, 0xf7f, 0xf9f, 0xfbf, 0xfdf, 0xfff
);

*Screen_t Screen;
*Window_t Window;

uint Seed;

[COUNT, COUNT] int Cell;

/*
 * random - return a random number 0 - passed range.
 */

proc random(uint rang)uint:

    if rang = 0 then
    0
    else
    Seed := Seed * 17137 + 4287;
    Seed := (Seed >> 8) >< (Seed << 8);
    Seed % rang
    fi
corp;

/*
 * set - set a given spot in Cell.
 */

proc set(uint l, c, size; int height)void:
    uint rang;

    rang := Range[size];
    height := height + random(rang) - (rang + 1) / 2;
    Cell[l, c] := height;
corp;

/*
 * grow - grow the basic scenery heights.
 */

proc grow()void:
    uint l, c, i, step, nextStep, l1, l2, c1, c2;

    Cell[0, 0] := 0;
    step := COUNT;
    for i from 0 upto SIZE - 1 do
    nextStep := step / 2;
    for l from 0 by step upto COUNT - 1 do
        l1 := l + nextStep;
        l2 := l + step;
        if l2 = COUNT then
        l2 := 0;
        fi;
        for c from 0 by step upto COUNT - 1 do
        c1 := c + nextStep;
        c2 := c + step;
        if c2 = COUNT then
            c2 := 0;
        fi;
        set(l, c1, i, (Cell[l, c] + Cell[l, c2] + 1) / 2);
        set(l1, c, i, (Cell[l, c] + Cell[l2, c] + 1) / 2);
        set(l1, c1, i, (Cell[l, c] + Cell[l, c2] +
                Cell[l2, c] + Cell[l2, c2] + 2) / 4);
        od;
    od;
    step := nextStep;
    od;
corp;

/*
 * display - display the resulting scenery.
 */

proc display()void:
    uint l, c;
    int height;

    for l from 0 upto WINDOW_HEIGHT - 1 do
    for c from 0 upto WINDOW_WIDTH - 1 do
        height := Cell[l, c];
        SetAPen(Window*.w_RPort,
            if height < 0 then
            0
            elif height >= COLOURS then
            COLOURS - 1
            else
            height
            fi);
        pretend(WritePixel(Window*.w_RPort, c, l), void);
    od;
    od;
corp;

/*
 * main program.
 */

proc main()void:
    NewWindow_t newWindow;
    DateStamp_t ds;
    IntuiText_t bodyText, positiveText, negativeText;

    bodyText := IntuiText_t(COLOURS - 1, 0, 0, 51, 5, nil, nil, nil);
    bodyText.it_IText := "Done";
    positiveText := IntuiText_t(COLOURS - 1, 0, 0, 7, 3, nil, nil, nil);
    positiveText.it_IText := "Next";
    negativeText := IntuiText_t(COLOURS - 1, 0, 0, 7, 3, nil, nil, nil);
    negativeText.it_IText := "Quit";
    if OpenIntuitionLibrary(0) ~= nil then
    if OpenGraphicsLibrary(0) ~= nil then
        if OpenDosLibrary(0) ~= nil then
        Screen := OpenScreen(&NewScreen_t(
            0, 0, SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_DEPTH, 0, 1,
            0x0, CUSTOMSCREEN, nil, nil, nil, nil));
        if Screen ~= nil then
            LoadRGB4(&Screen*.sc_ViewPort, &ColourMap[0], COLOURS);
            newWindow := NewWindow_t(
            0, 0, WINDOW_WIDTH, WINDOW_HEIGHT,
            FREEPEN, FREEPEN,
            0x0, BORDERLESS | ACTIVATE | NOCAREREFRESH,
            nil, nil, nil, nil, nil, 0, 0, 0, 0,
            CUSTOMSCREEN);
            newWindow.nw_Screen := Screen;
            Window := OpenWindow(&newWindow);
            if Window ~= nil then
            DateStamp(&ds);
            Seed := (ds.ds_Minute >< ds.ds_Tick) | 1;
            while
                grow();
                display();
                AutoRequest(Window, &bodyText, &positiveText,
                    &negativeText, 0x0, 0x0, 150, 50)
            do
            od;
            CloseWindow(Window);
            fi;
            CloseScreen(Screen);
        fi;
        CloseDosLibrary();
        fi;
        CloseGraphicsLibrary();
    fi;
    CloseIntuitionLibrary();
    fi;
corp;