Web, Commodore, Windows version, Linux standalone, Windows Screensaver complete.
This commit is contained in:
The Dust Council
parent
47730936de
commit
9257f21598
19 changed files with 794 additions and 18 deletions
311
c64/vectorgons.c
Normal file
311
c64/vectorgons.c
Normal file
|
|
@ -0,0 +1,311 @@
|
|||
/* ===========================================================================
|
||||
* VECTORGONS -- Commodore 64 edition
|
||||
* ---------------------------------------------------------------------------
|
||||
* A tumbling-wireframe vector demo for the C64, a tiny cousin of the desktop /
|
||||
* web Vectorgons. The 1 MHz 6510 has no FPU, so everything here is integer
|
||||
* fixed-point: a 256-entry signed sine table (scale 128) drives the 3-D
|
||||
* rotation, points are perspective-projected with integer division, and edges
|
||||
* are drawn into the VIC-II hi-res bitmap with a Bresenham line routine.
|
||||
*
|
||||
* Per the brief the glass / metal / mirror objects are dropped (no shading on
|
||||
* a 1-bit bitmap) -- what remains is the heart of Vectorgons: rotating
|
||||
* polytopes, cycling through a small library of 3-D shapes plus a 4-D
|
||||
* tesseract shadow, in classic monochrome vector-graphics style.
|
||||
*
|
||||
* Display : 320x200 hi-res bitmap at $2000, colour cells in screen RAM $0400.
|
||||
* Build : cc65 (cl65 -t c64 -C c64-vg.cfg). See the Makefile in this dir.
|
||||
* Controls: press any key to quit back to BASIC.
|
||||
* ===========================================================================
|
||||
*/
|
||||
|
||||
#include <string.h>
|
||||
#include <peekpoke.h>
|
||||
|
||||
/* ---- VIC-II / memory layout ------------------------------------------- */
|
||||
#define BITMAP ((unsigned char *)0x2000) /* 8 KB hi-res bitmap */
|
||||
#define SCREEN ((unsigned char *)0x0400) /* colour cells (1000 bytes) */
|
||||
#define VIC_D011 0xD011
|
||||
#define VIC_D016 0xD016
|
||||
#define VIC_D018 0xD018
|
||||
#define VIC_D020 0xD020 /* border colour */
|
||||
#define VIC_D021 0xD021 /* background colour */
|
||||
#define KBD_NDX 0x00C6 /* keyboard buffer count */
|
||||
|
||||
/* ---- projection constants (model units) ------------------------------- */
|
||||
#define PROJ 224 /* focal length */
|
||||
#define DIST 140 /* camera distance */
|
||||
#define SCRW 320
|
||||
#define SCRH 200
|
||||
|
||||
#define MAXV 16 /* tesseract has the most vertices */
|
||||
|
||||
/* round(127 * sin(i * 2pi / 256)) -- fixed-point scale 128 (>>7) */
|
||||
static const signed char sintab[256] = {
|
||||
0, 3, 6, 9, 12, 16, 19, 22, 25, 28, 31, 34, 37, 40, 43, 46,
|
||||
49, 51, 54, 57, 60, 63, 65, 68, 71, 73, 76, 78, 81, 83, 85, 88,
|
||||
90, 92, 94, 96, 98, 100, 102, 104, 106, 107, 109, 111, 112, 113, 115, 116,
|
||||
117, 118, 120, 121, 122, 122, 123, 124, 125, 125, 126, 126, 126, 127, 127, 127,
|
||||
127, 127, 127, 127, 126, 126, 126, 125, 125, 124, 123, 122, 122, 121, 120, 118,
|
||||
117, 116, 115, 113, 112, 111, 109, 107, 106, 104, 102, 100, 98, 96, 94, 92,
|
||||
90, 88, 85, 83, 81, 78, 76, 73, 71, 68, 65, 63, 60, 57, 54, 51,
|
||||
49, 46, 43, 40, 37, 34, 31, 28, 25, 22, 19, 16, 12, 9, 6, 3,
|
||||
0, -3, -6, -9, -12, -16, -19, -22, -25, -28, -31, -34, -37, -40, -43, -46,
|
||||
-49, -51, -54, -57, -60, -63, -65, -68, -71, -73, -76, -78, -81, -83, -85, -88,
|
||||
-90, -92, -94, -96, -98, -100, -102, -104, -106, -107, -109, -111, -112, -113, -115, -116,
|
||||
-117, -118, -120, -121, -122, -122, -123, -124, -125, -125, -126, -126, -126, -127, -127, -127,
|
||||
-127, -127, -127, -127, -126, -126, -126, -125, -125, -124, -123, -122, -122, -121, -120, -118,
|
||||
-117, -116, -115, -113, -112, -111, -109, -107, -106, -104, -102, -100, -98, -96, -94, -92,
|
||||
-90, -88, -85, -83, -81, -78, -76, -73, -71, -68, -65, -63, -60, -57, -54, -51,
|
||||
-49, -46, -43, -40, -37, -34, -31, -28, -25, -22, -19, -16, -12, -9, -6, -3,
|
||||
};
|
||||
|
||||
/* ===========================================================================
|
||||
* Shape library. Vertices are signed-char model coords (~ +/-45); edges are
|
||||
* vertex-index pairs. Skip metal/glass/mirror -- pure wireframe polytopes.
|
||||
* ===========================================================================
|
||||
*/
|
||||
static const signed char tetra_v[4][3] = {
|
||||
{ 45, 45, 45}, { 45,-45,-45}, {-45, 45,-45}, {-45,-45, 45}
|
||||
};
|
||||
static const unsigned char tetra_e[6][2] = {
|
||||
{0,1},{0,2},{0,3},{1,2},{1,3},{2,3}
|
||||
};
|
||||
|
||||
static const signed char cube_v[8][3] = {
|
||||
{-40,-40,-40},{ 40,-40,-40},{ 40, 40,-40},{-40, 40,-40},
|
||||
{-40,-40, 40},{ 40,-40, 40},{ 40, 40, 40},{-40, 40, 40}
|
||||
};
|
||||
static const unsigned char cube_e[12][2] = {
|
||||
{0,1},{1,2},{2,3},{3,0}, {4,5},{5,6},{6,7},{7,4}, {0,4},{1,5},{2,6},{3,7}
|
||||
};
|
||||
|
||||
static const signed char octa_v[6][3] = {
|
||||
{ 50,0,0},{-50,0,0},{0, 50,0},{0,-50,0},{0,0, 50},{0,0,-50}
|
||||
};
|
||||
static const unsigned char octa_e[12][2] = {
|
||||
{0,2},{0,3},{0,4},{0,5},{1,2},{1,3},{1,4},{1,5},{2,4},{2,5},{3,4},{3,5}
|
||||
};
|
||||
|
||||
static const signed char pyra_v[5][3] = {
|
||||
{-40,-30,-40},{ 40,-30,-40},{ 40,-30, 40},{-40,-30, 40},{ 0, 48, 0}
|
||||
};
|
||||
static const unsigned char pyra_e[8][2] = {
|
||||
{0,1},{1,2},{2,3},{3,0},{4,0},{4,1},{4,2},{4,3}
|
||||
};
|
||||
|
||||
/* Stellated "star": two interpenetrating tetrahedra (Stella octangula). */
|
||||
static const signed char star_v[8][3] = {
|
||||
{ 45, 45, 45},{ 45,-45,-45},{-45, 45,-45},{-45,-45, 45},
|
||||
{-45,-45,-45},{-45, 45, 45},{ 45,-45, 45},{ 45, 45,-45}
|
||||
};
|
||||
static const unsigned char star_e[12][2] = {
|
||||
{0,1},{0,2},{0,3},{1,2},{1,3},{2,3},
|
||||
{4,5},{4,6},{4,7},{5,6},{5,7},{6,7}
|
||||
};
|
||||
|
||||
/* Tesseract shadow: an inner cube nested in an outer cube, corners linked. */
|
||||
static const signed char tess_v[16][3] = {
|
||||
{-20,-20,-20},{ 20,-20,-20},{ 20, 20,-20},{-20, 20,-20},
|
||||
{-20,-20, 20},{ 20,-20, 20},{ 20, 20, 20},{-20, 20, 20},
|
||||
{-46,-46,-46},{ 46,-46,-46},{ 46, 46,-46},{-46, 46,-46},
|
||||
{-46,-46, 46},{ 46,-46, 46},{ 46, 46, 46},{-46, 46, 46}
|
||||
};
|
||||
static const unsigned char tess_e[32][2] = {
|
||||
{0,1},{1,2},{2,3},{3,0},{4,5},{5,6},{6,7},{7,4},{0,4},{1,5},{2,6},{3,7},
|
||||
{8,9},{9,10},{10,11},{11,8},{12,13},{13,14},{14,15},{15,12},
|
||||
{8,12},{9,13},{10,14},{11,15},
|
||||
{0,8},{1,9},{2,10},{3,11},{4,12},{5,13},{6,14},{7,15}
|
||||
};
|
||||
|
||||
typedef struct {
|
||||
const signed char (*v)[3];
|
||||
unsigned char nv;
|
||||
const unsigned char (*e)[2];
|
||||
unsigned char ne;
|
||||
} Shape;
|
||||
|
||||
static const Shape shapes[] = {
|
||||
{ cube_v, 8, cube_e, 12 },
|
||||
{ octa_v, 6, octa_e, 12 },
|
||||
{ tetra_v, 4, tetra_e, 6 },
|
||||
{ star_v, 8, star_e, 12 },
|
||||
{ pyra_v, 5, pyra_e, 8 },
|
||||
{ tess_v, 16, tess_e, 32 }
|
||||
};
|
||||
#define NSHAPES (sizeof(shapes) / sizeof(shapes[0]))
|
||||
|
||||
/* Foreground colours cycled per shape (upper nibble; background black). */
|
||||
static const unsigned char palette[] = { 3, 14, 1, 7, 13, 5, 4 };
|
||||
#define NCOL (sizeof(palette) / sizeof(palette[0]))
|
||||
|
||||
/* ---- precomputed bitmap address tables (built at startup) ------------- */
|
||||
static unsigned int ytab[SCRH]; /* (y>>3)*320 + (y&7) */
|
||||
static unsigned int xtab[SCRW]; /* (x>>3)*8 */
|
||||
static unsigned char mtab[SCRW]; /* 0x80 >> (x&7) */
|
||||
|
||||
/* ---- per-frame projected coordinates ---------------------------------- */
|
||||
static int sx[MAXV], sy[MAXV]; /* current frame */
|
||||
static int psx[MAXV], psy[MAXV]; /* previous frame */
|
||||
|
||||
static void build_tables(void)
|
||||
{
|
||||
unsigned int y, x;
|
||||
for (y = 0; y < SCRH; ++y)
|
||||
ytab[y] = (unsigned int)((y >> 3) * 320 + (y & 7));
|
||||
for (x = 0; x < SCRW; ++x) {
|
||||
xtab[x] = (unsigned int)((x >> 3) * 8);
|
||||
mtab[x] = (unsigned char)(0x80 >> (x & 7));
|
||||
}
|
||||
}
|
||||
|
||||
/* Set bitmap mode, bitmap @ $2000, colour cells @ $0400, black border. */
|
||||
static void gfx_on(unsigned char colour)
|
||||
{
|
||||
memset(BITMAP, 0, 8000); /* clear bitmap */
|
||||
memset(SCREEN, colour, 1000); /* fg/bg per cell */
|
||||
POKE(VIC_D020, 0); /* black border */
|
||||
POKE(VIC_D021, 0); /* black background */
|
||||
POKE(VIC_D018, 0x18); /* screen $0400, bmp $2000 */
|
||||
POKE(VIC_D016, PEEK(VIC_D016) & 0xEF);/* hi-res (MCM off) */
|
||||
POKE(VIC_D011, PEEK(VIC_D011) | 0x20);/* bitmap mode (BMM on) */
|
||||
}
|
||||
|
||||
/* Restore the normal text screen on the way out. */
|
||||
static void gfx_off(void)
|
||||
{
|
||||
POKE(VIC_D011, PEEK(VIC_D011) & 0xDF);/* BMM off */
|
||||
POKE(VIC_D018, 0x15); /* default char/screen */
|
||||
POKE(VIC_D020, 14); /* default border */
|
||||
POKE(VIC_D021, 6); /* default background */
|
||||
memset(SCREEN, 0x20, 1000); /* blank text screen */
|
||||
memset((unsigned char *)0xD800, 14, 1000); /* light-blue text */
|
||||
}
|
||||
|
||||
/* Plot one pixel. set != 0 turns the pixel on, otherwise clears it.
|
||||
* Off-screen points are silently clipped. */
|
||||
static void plot(int x, int y, unsigned char set)
|
||||
{
|
||||
unsigned char *p;
|
||||
if (x < 0 || x >= SCRW || y < 0 || y >= SCRH)
|
||||
return;
|
||||
p = BITMAP + ytab[y] + xtab[x];
|
||||
if (set)
|
||||
*p |= mtab[x];
|
||||
else
|
||||
*p &= (unsigned char)~mtab[x];
|
||||
}
|
||||
|
||||
/* Integer Bresenham line from (x0,y0) to (x1,y1). */
|
||||
static void line(int x0, int y0, int x1, int y1, unsigned char set)
|
||||
{
|
||||
int dx = (x1 > x0) ? (x1 - x0) : (x0 - x1);
|
||||
int dy = -((y1 > y0) ? (y1 - y0) : (y0 - y1));
|
||||
int sx0 = (x0 < x1) ? 1 : -1;
|
||||
int sy0 = (y0 < y1) ? 1 : -1;
|
||||
int err = dx + dy;
|
||||
int e2;
|
||||
for (;;) {
|
||||
plot(x0, y0, set);
|
||||
if (x0 == x1 && y0 == y1)
|
||||
break;
|
||||
e2 = err << 1;
|
||||
if (e2 >= dy) { err += dy; x0 += sx0; }
|
||||
if (e2 <= dx) { err += dx; y0 += sy0; }
|
||||
}
|
||||
}
|
||||
|
||||
/* Rotate the current shape's vertices by (ax,ay,az) and perspective-project
|
||||
* into sx[]/sy[]. All maths integer; sin/cos read from sintab (>>7). */
|
||||
static void project(const Shape *sh,
|
||||
unsigned char ax, unsigned char ay, unsigned char az)
|
||||
{
|
||||
int sinx = sintab[ax];
|
||||
int cosx = sintab[(unsigned char)(ax + 64)];
|
||||
int siny = sintab[ay];
|
||||
int cosy = sintab[(unsigned char)(ay + 64)];
|
||||
int sinz = sintab[az];
|
||||
int cosz = sintab[(unsigned char)(az + 64)];
|
||||
unsigned char i;
|
||||
|
||||
for (i = 0; i < sh->nv; ++i) {
|
||||
int x = sh->v[i][0];
|
||||
int y = sh->v[i][1];
|
||||
int z = sh->v[i][2];
|
||||
int t;
|
||||
int denom;
|
||||
|
||||
/* rotate about X */
|
||||
t = (y * cosx - z * sinx) >> 7;
|
||||
z = (y * sinx + z * cosx) >> 7;
|
||||
y = t;
|
||||
/* rotate about Y */
|
||||
t = (x * cosy + z * siny) >> 7;
|
||||
z = (z * cosy - x * siny) >> 7;
|
||||
x = t;
|
||||
/* rotate about Z */
|
||||
t = (x * cosz - y * sinz) >> 7;
|
||||
y = (x * sinz + y * cosz) >> 7;
|
||||
x = t;
|
||||
|
||||
denom = z + DIST; /* always positive given coord ranges */
|
||||
sx[i] = 160 + (x * PROJ) / denom;
|
||||
sy[i] = 100 - (y * PROJ) / denom;
|
||||
}
|
||||
}
|
||||
|
||||
void main(void)
|
||||
{
|
||||
unsigned char shape = 0;
|
||||
unsigned char colidx = 0;
|
||||
unsigned char ax = 0, ay = 0, az = 0;
|
||||
unsigned int frame = 0;
|
||||
unsigned char first = 1;
|
||||
const Shape *sh;
|
||||
unsigned char i;
|
||||
|
||||
build_tables();
|
||||
POKE(KBD_NDX, 0); /* flush keyboard buffer */
|
||||
gfx_on(palette[0] << 4);
|
||||
|
||||
sh = &shapes[0];
|
||||
|
||||
for (;;) {
|
||||
/* --- advance rotation (three different rates => tumble) --- */
|
||||
ax += 2;
|
||||
ay += 3;
|
||||
az += 1;
|
||||
|
||||
project(sh, ax, ay, az);
|
||||
|
||||
/* --- erase previous frame's edges, then draw the new ones --- */
|
||||
if (!first) {
|
||||
for (i = 0; i < sh->ne; ++i) {
|
||||
unsigned char a = sh->e[i][0], b = sh->e[i][1];
|
||||
line(psx[a], psy[a], psx[b], psy[b], 0);
|
||||
}
|
||||
}
|
||||
for (i = 0; i < sh->ne; ++i) {
|
||||
unsigned char a = sh->e[i][0], b = sh->e[i][1];
|
||||
line(sx[a], sy[a], sx[b], sy[b], 1);
|
||||
}
|
||||
for (i = 0; i < sh->nv; ++i) { psx[i] = sx[i]; psy[i] = sy[i]; }
|
||||
first = 0;
|
||||
|
||||
/* --- cycle to the next shape every ~200 frames --- */
|
||||
if (++frame >= 200) {
|
||||
frame = 0;
|
||||
shape = (unsigned char)((shape + 1) % NSHAPES);
|
||||
colidx = (unsigned char)((colidx + 1) % NCOL);
|
||||
sh = &shapes[shape];
|
||||
first = 1;
|
||||
memset(BITMAP, 0, 8000); /* fresh canvas */
|
||||
memset(SCREEN, palette[colidx] << 4, 1000);
|
||||
}
|
||||
|
||||
/* --- quit on any keypress --- */
|
||||
if (PEEK(KBD_NDX) != 0)
|
||||
break;
|
||||
}
|
||||
|
||||
gfx_off();
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue