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Removed the 'history' dead code and consolidated the pixel antialiasing

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code.
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Bruce Hill 2019-03-19 20:17:00 -07:00
parent 44696fff16
commit 866496d88d
1 changed files with 17 additions and 37 deletions
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54
2pend.c
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@ -7,8 +7,6 @@
#include <unistd.h> #include <unistd.h>
#include <math.h> #include <math.h>
#define HISTORY_LEN 8
typedef struct { typedef struct {
double a, p; double a, p;
} pendulum_t; } pendulum_t;
@ -43,7 +41,18 @@ static state_t step(state_t state, state_t derivative, double dt)
return next; return next;
} }
static void draw(state_t state, int color) static inline void draw_pix(double x, double y, int W, int H, double *prev)
{
double b = sqrt(2*((x-floor(x+.5))*(x-floor(x+.5)) + (y-floor(y+.5))*(y-floor(y+.5))));
int ix = (int)x, iy = (int)y;
if (b > prev[iy*W+ix] && b > .1) {
prev[iy*W+ix] = b;
int color = color_ramp[(int)(sizeof(color_ramp)/sizeof(int) * b)];
tb_change_cell(ix, iy, ' ', 0, color);
}
}
static void draw(state_t state)
{ {
// TODO: properly walk along cells // TODO: properly walk along cells
int W = tb_width(), H = tb_height(); int W = tb_width(), H = tb_height();
@ -52,31 +61,17 @@ static void draw(state_t state, int color)
double x = W/2, y = H/2; double x = W/2, y = H/2;
double step = 0.25; double step = 0.25;
for (double p = 0; p <= len*L1; p += step) { for (double p = 0; p <= len*L1; p += step) {
double b = (sqrt(2*((x-floor(x+.5))*(x-floor(x+.5)) + (y-floor(y+.5))*(y-floor(y+.5))))); draw_pix(x, y, W, H, brightness);
if (b > brightness[(int)y*W+(int)x]) brightness[(int)y*W+(int)x] = b; draw_pix(x+1.0, y, W, H, brightness);
b = (sqrt(2*((x+1.-floor(x+1.5))*(x+1.-floor(x+1.5)) + (y-floor(y+.5))*(y-floor(y+.5)))));
if (b > brightness[(int)y*W+(int)x+1]) brightness[(int)y*W+(int)x+1] = b;
//tb_change_cell((int)x, (int)y, ' ', 0, color);
x += step*cos(state.p1.a + M_PI/2)*2; x += step*cos(state.p1.a + M_PI/2)*2;
y += step*sin(state.p1.a + M_PI/2); y += step*sin(state.p1.a + M_PI/2);
} }
for (double p = 0; p <= len*L2; p += step) { for (double p = 0; p <= len*L2; p += step) {
double b = (sqrt(2*((x-floor(x+.5))*(x-floor(x+.5)) + (y-floor(y+.5))*(y-floor(y+.5))))); draw_pix(x, y, W, H, brightness);
if (b > brightness[(int)y*W+(int)x]) brightness[(int)y*W+(int)x] = b; draw_pix(x+1.0, y, W, H, brightness);
b = (sqrt(2*((x+1.-floor(x+1.5))*(x+1.-floor(x+1.5)) + (y-floor(y+.5))*(y-floor(y+.5)))));
if (b > brightness[(int)y*W+(int)x+1]) brightness[(int)y*W+(int)x+1] = b;
//tb_change_cell((int)x, (int)y, ' ', 0, color);
x += step*cos(state.p2.a + M_PI/2)*2; x += step*cos(state.p2.a + M_PI/2)*2;
y += step*sin(state.p2.a + M_PI/2); y += step*sin(state.p2.a + M_PI/2);
} }
for (int y=0; y<H; y++) for (int x=0; x<W; x++) {
double b = brightness[y*W+x];
if (b > 0) {
color = color_ramp[(int)(sizeof(color_ramp)/sizeof(int) * b)];
tb_change_cell((int)x, (int)y, ' ', 0, color);
}
}
free(brightness); free(brightness);
} }
@ -90,16 +85,12 @@ int main(int argc, char **argv) {
tb_select_output_mode(TB_OUTPUT_256); tb_select_output_mode(TB_OUTPUT_256);
state_t state; state_t state;
state_t history[HISTORY_LEN];
randomize: randomize:
state.p1.a = M_PI/2 + M_PI*(double)rand()/RAND_MAX; state.p1.a = M_PI/2 + M_PI*(double)rand()/RAND_MAX;
state.p2.a = M_PI/2 + M_PI*(double)rand()/RAND_MAX; state.p2.a = M_PI/2 + M_PI*(double)rand()/RAND_MAX;
state.p1.p = 0; state.p1.p = 0;
state.p2.p = 0; state.p2.p = 0;
for (int i=0; i<HISTORY_LEN; i++) {
history[i] = state;
}
while (1) { while (1) {
tb_clear(); tb_clear();
@ -116,18 +107,7 @@ int main(int argc, char **argv) {
state.p1.p += dt/6.*(k1.p1.p + 2.*k2.p1.p + 2.*k3.p1.p + k4.p1.p); state.p1.p += dt/6.*(k1.p1.p + 2.*k2.p1.p + 2.*k3.p1.p + k4.p1.p);
state.p2.p += dt/6.*(k1.p2.p + 2.*k2.p2.p + 2.*k3.p2.p + k4.p2.p); state.p2.p += dt/6.*(k1.p2.p + 2.*k2.p2.p + 2.*k3.p2.p + k4.p2.p);
} }
for (int i=0; i<HISTORY_LEN-1; i++) { draw(state);
history[i] = history[i+1];
}
history[HISTORY_LEN-1] = state;
/*
for (int i=0; i<HISTORY_LEN; i++) {
//draw(history[i], color_ramp[((i+1)*(sizeof(color_ramp)/sizeof(int)))/(HISTORY_LEN+1)]);
draw(history[i], color_ramp[((i+1)*(sizeof(color_ramp)/sizeof(int)/2))/(HISTORY_LEN+1)]);
}
*/
draw(state, 231);
//draw(state, 7);
tb_present(); tb_present();
usleep(60000); usleep(60000);
struct tb_event ev; struct tb_event ev;