* 浮動小数点でキューブ回転したい #2
-(by [[K]], 2019.11.26)
** (0)
-[[p20191125a]]に対して、少し色を変更してみました。フルカラーを使っています。
** (1)
-blaライブラリを使って描画しています。
#include <stdio.h>
#include <windows.h>
#include <math.h>
#define STATIC static
#include "bla.c"
void drawObj();
void drawPoly(int j, int c);
double vx[8], vy[8], vz[8], centerz4[6];
int scx[8], scy[8];
int squar[24] = { 0,4,6,2, 1,3,7,5, 0,2,3,1, 0,1,5,4, 4,5,7,6, 6,7,3,2 };
bla_Window *win;
int bla_main(int argc, const char **argv)
{
win = bla_openWin(256, 160, "kcube2019b", 1);
static double vertx[8] = { 50.0, 50.0, 50.0, 50.0, -50.0, -50.0, -50.0, -50.0 };
static double verty[8] = { 50.0, 50.0, -50.0, -50.0, 50.0, 50.0, -50.0, -50.0 };
static double vertz[8] = { 50.0, -50.0, 50.0, -50.0, 50.0, -50.0, 50.0, -50.0 };
int thx = 0, thy = 0, thz = 0, i, l;
const double toRad = 3.14159265358979323 / 0x8000;
for (;;) {
thx = (thx + 182) & 0xffff;
thy = (thy + 273) & 0xffff;
thz = (thz + 364) & 0xffff;
double xp = cos(thx * toRad), xa = sin(thx * toRad);
double yp = cos(thy * toRad), ya = sin(thy * toRad);
double zp = cos(thz * toRad), za = sin(thz * toRad);
for (i = 0; i < 8; i++) {
double xt, yt, zt;
zt = vertz[i] * xp + verty[i] * xa;
yt = verty[i] * xp - vertz[i] * xa;
xt = vertx[i] * yp + zt * ya;
vz[i] = zt * yp - vertx[i] * ya;
vx[i] = xt * zp - yt * za;
vy[i] = yt * zp + xt * za;
}
l = 0; for (i = 0; i < 6; i++) {
centerz4[i] = vz[squar[l + 0]] + vz[squar[l + 1]] + vz[squar[l + 2]] + vz[squar[l + 3]] + 1024.0;
l += 4;
}
bla_fillRect(win, 160, 160, 40, 0, bla_rgb(0, 0, 0));
drawObj();
bla_flushAll(win);
bla_waitEx(50);
}
}
void drawObj()
{
int i;
for (i = 0; i < 8; i++) {
double t = 300.0 / (vz[i] + 400.0);
scx[i] = (vx[i] * t) + 128;
scy[i] = (vy[i] * t) + 80;
}
for (;;) {
double max = 0.0;
int j = -1, k;
for (k = 0; k < 6; k++) {
if (max < centerz4[k]) {
max = centerz4[k];
j = k;
}
}
if (j < 0) break;
i = j * 4;
centerz4[j] = 0.0;
double e0x = vx[squar[i + 1]] - vx[squar[i + 0]];
double e0y = vy[squar[i + 1]] - vy[squar[i + 0]];
double e0z = vz[squar[i + 1]] - vz[squar[i + 0]];
double e1x = vx[squar[i + 2]] - vx[squar[i + 1]];
double e1y = vy[squar[i + 2]] - vy[squar[i + 1]];
double e1z = vz[squar[i + 2]] - vz[squar[i + 1]];
double t = 1.0 / sqrt(e0x * e0x + e0y * e0y + e0z * e0z);
e0x *= t; e0y *= t; e0z *= t;
t = 1.0 / sqrt(e1x * e1x + e1y * e1y + e1z * e1z);
e1x *= t; e1y *= t; e1z *= t;
if (e0x * e1y <= e0y * e1x)
if (e0x * e1y <= e0y * e1x) {
double e0z = vz[squar[i + 1]] - vz[squar[i + 0]];
double e1z = vz[squar[i + 2]] - vz[squar[i + 1]];
double t = 1.0 / sqrt(e0x * e0x + e0y * e0y + e0z * e0z);
e0x *= t; e0y *= t; e0z *= t;
t = 1.0 / sqrt(e1x * e1x + e1y * e1y + e1z * e1z);
e1x *= t; e1y *= t; e1z *= t;
drawPoly(j, (int) ((e0y * e1x - e0x * e1y) * 319.9));
}
}
}
void drawPoly(int j, int c)
{
int i = j * 4, i1 = i + 3;
int p0x = scx[squar[i1]], p0y = scy[squar[i1]], p1x, p1y;
int y, ymin = 0x7fffffff, ymax = 0, x, dx, y0, y1;
int *buf, buf0[160], buf1[160];
for (i = i; i <= i1; i++) {
p1x = scx[squar[i]];
p1y = scy[squar[i]];
if (ymin > p1y) ymin = p1y;
if (ymax < p1y) ymax = p1y;
if (p0y != p1y) {
if (p0y < p1y) {
buf = buf0; y0 = p0y; y1 = p1y; dx = p1x - p0x; x = p0x;
} else {
buf = buf1; y0 = p1y; y1 = p0y; dx = p0x - p1x; x = p1x;
}
x <<= 16;
dx = (dx << 16) / (y1 - y0);
if (dx >= 0)
x += 0x8000;
else
x -= 0x8000;
for (y = y0; y <= y1; y++) {
buf[y] = x >> 16;
x += dx;
}
}
p0x = p1x;
p0y = p1y;
}
if (c < 256)
c = bla_rgb(c, c, c >> 1);
else
c = bla_rgb(255, 255, c - 128);
for (y = ymin; y <= ymax; y++) {
p0x = buf0[y];
p1x = buf1[y];
if (p0x <= p1x)
bla_fillRect(win, p1x - p0x + 1, 1, p0x, y, c);
else
bla_fillRect(win, p0x - p1x + 1, 1, p1x, y, c);
}
}
* こめんと欄
#comment
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