--- /dev/null
+GCURVES
+curve {
+ type bspline
+ cpcount 76
+ cp 0.770551 -0.12 0 1
+ cp 0.770551 -0.12 0 1
+ cp 0.770551 -0.12 0 1
+ cp 0.464919 -0.423409 0 1
+ cp 0.157055 -0.7461 0 1
+ cp 0.000942409 -0.760054 0 1
+ cp -0.156914 -0.742611 0 1
+ cp -0.460417 -0.424282 0 1
+ cp -0.736884 -0.163513 0 1
+ cp -0.761304 -0.000423729 0 1
+ cp -0.734268 0.167898 0 1
+ cp -0.442102 0.441749 0 1
+ cp -0.17959 0.726937 0 1
+ cp 7.04117e-05 0.762695 0 1
+ cp 0.184963 0.724321 0 1
+ cp 0.403869 0.483612 0 1
+ cp 0.758539 0.124617 0 1
+ cp 0.758539 0.124617 0 1
+ cp 0.758539 0.124617 0 1
+ cp 0.586597 0.120587 0 1
+ cp 0.586597 0.120587 0 1
+ cp 0.586597 0.120587 0 1
+ cp 0.3118 0.392285 0 1
+ cp 0.102777 0.620188 0 1
+ cp 0.000962065 0.630302 0 1
+ cp -0.0947842 0.622211 0 1
+ cp -0.353704 0.344412 0 1
+ cp -0.616669 0.104372 0 1
+ cp -0.630828 -0.000814512 0 1
+ cp -0.611275 -0.11544 0 1
+ cp -0.361121 -0.341995 0 1
+ cp -0.0974812 -0.61912 0 1
+ cp 0.000287853 -0.634628 0 1
+ cp 0.0987312 -0.622491 0 1
+ cp 0.320566 -0.385148 0 1
+ cp 0.578731 -0.12 0 1
+ cp 0.578731 -0.12 0 1
+ cp 0.578731 -0.12 0 1
+ cp 0.410366 -0.12 0 1
+ cp 0.410366 -0.12 0 1
+ cp 0.410366 -0.12 0 1
+ cp 0.221153 -0.305467 0 1
+ cp 0.0576008 -0.481569 0 1
+ cp -0.00106066 -0.497751 0 1
+ cp -0.0603964 -0.477523 0 1
+ cp -0.270768 -0.252317 0 1
+ cp -0.479118 -0.0567789 0 1
+ cp -0.491929 0.000533998 0 1
+ cp -0.479792 0.0558241 0 1
+ cp -0.27414 0.245968 0 1
+ cp -0.0543279 0.476568 0 1
+ cp 0.000287883 0.493425 0 1
+ cp 0.0522066 0.47994 0 1
+ cp 0.195152 0.330252 0 1
+ cp 0.397571 0.12191 0 1
+ cp 0.397571 0.12191 0 1
+ cp 0.397571 0.12191 0 1
+ cp 0.228891 0.12 0 1
+ cp 0.228891 0.12 0 1
+ cp 0.228891 0.12 0 1
+ cp 0.133119 0.210906 0 1
+ cp 0.0366984 0.310024 0 1
+ cp 0.000287898 0.329578 0 1
+ cp -0.032077 0.314069 0 1
+ cp -0.177045 0.161684 0 1
+ cp -0.31055 0.0369445 0 1
+ cp -0.327407 -0.000140294 0 1
+ cp -0.308528 -0.0399222 0 1
+ cp -0.172999 -0.170056 0 1
+ cp -0.0334256 -0.312327 0 1
+ cp 0.000287853 -0.325812 0 1
+ cp 0.0353499 -0.315024 0 1
+ cp 0.108845 -0.236809 0 1
+ cp 0.227761 -0.12 0 1
+ cp 0.227761 -0.12 0 1
+ cp 0.227761 -0.12 0 1
+}
--- /dev/null
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <ctype.h>
+#include <cgmath/cgmath.h>
+#include "logo.h"
+
+struct cpnode {
+ cgm_vec2 p;
+ struct cpnode *next;
+};
+
+#define CPLERP(res, a, b, t) \
+ do { \
+ (res).x = (a).x + ((b).x - (a).x) * (t); \
+ (res).y = (a).y + ((b).y - (a).y) * (t); \
+ } while(0)
+
+static cgm_vec2 *cp;
+static int numcp;
+
+int init_logo(const char *fname)
+{
+ FILE *fp;
+ char buf[256];
+ struct cpnode *cpn, *cplist = 0, *cptail = 0;
+ int idx;
+
+ if(!(fp = fopen(fname, "rb"))) {
+ fprintf(stderr, "failed to load logo curve: %s\n", fname);
+ return -1;
+ }
+ fgets(buf, sizeof buf, fp);
+ if(memcmp(buf, "GCURVES", 7) != 0) {
+ fprintf(stderr, "invalid logo file: %s\n", fname);
+ fclose(fp);
+ return -1;
+ }
+
+ numcp = 0;
+ while(fgets(buf, sizeof buf, fp)) {
+ char *ptr;
+ cgm_vec2 v;
+
+ ptr = buf;
+ while(*ptr && isspace(*ptr)) ptr++;
+
+ if(sscanf(ptr, "cp %f %f", &v.x, &v.y) == 2) {
+ if(!(cpn = malloc(sizeof *cpn))) {
+ continue;
+ }
+
+ cpn->p.x = v.x;
+ cpn->p.y = v.y;
+ cpn->next = 0;
+
+ if(cplist) {
+ cptail->next = cpn;
+ cptail = cpn;
+ } else {
+ cplist = cptail = cpn;
+ }
+ numcp++;
+ }
+ }
+ fclose(fp);
+
+ if(numcp < 4) {
+ fprintf(stderr, "invalid logo file, found %d control points\n", numcp);
+ return -1;
+ }
+
+ if(!(cp = malloc(numcp * sizeof *cp))) {
+ fprintf(stderr, "failed to allocate curve of %d control points\n", numcp);
+ while(cplist) {
+ cpn = cplist;
+ cplist = cplist->next;
+ free(cpn);
+ }
+ return -1;
+ }
+
+ idx = 0;
+ while(cplist) {
+ cpn = cplist;
+ cplist = cplist->next;
+ cp[idx++] = cpn->p;
+ free(cpn);
+ }
+
+ return 0;
+}
+
+static void eval_seg(float *res, int a, int b, float t)
+{
+ int prev, next;
+
+ if(numcp == 2) {
+ res[0] = cp[a].x + (cp[b].x - cp[a].x) * t;
+ res[1] = cp[a].y + (cp[b].y - cp[a].y) * t;
+ return;
+ }
+
+ prev = a <= 0 ? a : a - 1;
+ next = b >= numcp - 1 ? b : b + 1;
+
+ res[0] = cgm_bspline(cp[prev].x, cp[a].x, cp[b].x, cp[next].x, t);
+ res[1] = cgm_bspline(cp[prev].y, cp[a].y, cp[b].y, cp[next].y, t);
+}
+
+void eval_logo(float *res, float t)
+{
+ int idx0, idx1;
+ float t0, t1, dt;
+
+ if(!cp || numcp <= 0) {
+ res[0] = res[1] = 0;
+ return;
+ }
+ if(numcp == 1) {
+ res[0] = cp[0].x;
+ res[1] = cp[0].y;
+ return;
+ }
+
+ if(t < 0.0f) t = 0.0f;
+ if(t > 1.0f) t = 1.0f;
+
+ idx0 = (int)floor(t * (numcp - 1));
+ if(idx0 > numcp - 2) idx0 = numcp - 2;
+ idx1 = idx0 + 1;
+
+ dt = 1.0f / (float)(numcp - 1);
+ t0 = (float)idx0 * dt;
+ t1 = (float)idx1 * dt;
+ t = (t - t0) / (t1 - t0);
+
+ eval_seg(res, idx0, idx1, t);
+}
#ifndef LOGO_H_
#define LOGO_H_
-#define LOGO_W 90
-#define LOGO_H 85
-
-static const float logocp[][2] = {
- {85, 48},
- {68.5, 64.5},
- {68.5, 64.5},
- {52, 81},
-
- {52, 81},
- {43, 89},
- {43, 89},
- {34, 81},
-
- {34, 81},
- {18.5, 66},
- {18.5, 66},
- {3, 51},
-
- {3, 51},
- {-5, 41.5},
- {-5, 41.5},
- {4, 32},
-
- {4, 32},
- {19, 17},
- {19, 17},
- {33, 3},
-
- {33, 3},
- {42, -5},
- {42, -5},
- {52, 3},
-
- {52, 3},
- {68, 19},
- {68, 19},
- {85, 35},
-
- {85, 35},
- {75, 35},
- {85, 35},
- {75, 35},
-
- {75, 35},
- {62, 22},
- {62, 22},
- {49, 10},
-
- {49, 10},
- {42, 4},
- {42, 4},
- {36, 10},
-
- {36, 10},
- {23, 22},
- {23, 22},
- {11, 35},
-
- {11, 35},
- {5, 42},
- {5, 42},
- {11, 49},
-
- {11, 49},
- {23, 61},
- {23, 61},
- {36, 74},
-
- {36, 74},
- {42, 79},
- {42, 79},
- {49, 74},
-
- {49, 74},
- {62, 61},
- {62, 61},
- {75, 48},
-
- {75, 48},
- {65, 48},
- {75, 48},
- {65, 48},
-
- {65, 48},
- {55.5, 57.5},
- {55.5, 57.5},
- {46, 67},
-
- {46, 67},
- {42.5, 70},
- {42.5, 70},
- {39, 67},
-
- {39, 67},
- {28, 56},
- {28, 56},
- {17, 45},
-};
-
-#define LOGOCP_SIZE (sizeof logocp / sizeof *logocp)
+int init_logo(const char *fname);
+void eval_logo(float *res, float t);
#endif /* LOGO_H_ */
#include <stdio.h>
#include <stdlib.h>
+#include <math.h>
#include <assert.h>
#include <GL/glut.h>
#include "logo.h"
-#define BEZ_SEG 16
+#define MSAA
int init(void);
void display(void);
void reshape(int x, int y);
void keyb(unsigned char key, int x, int y);
-void draw_bezier(float *cp, int sub);
+int nverts = 256;
int main(int argc, char **argv)
{
+ unsigned int flags = GLUT_RGB | GLUT_DOUBLE;
+#ifdef MSAA
+ flags |= GLUT_MULTISAMPLE;
+#endif
+
glutInit(&argc, argv);
glutInitWindowSize(800, 600);
- glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
+ glutInitDisplayMode(flags);
glutCreateWindow("census");
glutDisplayFunc(display);
int init(void)
{
- glEnable(GL_LINE_SMOOTH);
+ if(init_logo("data/census.curves") == -1) {
+ return -1;
+ }
+
+#ifdef MSAA
+ glEnable(GL_MULTISAMPLE);
+#endif
+
return 0;
}
+static void draw_disc(float x, float y, float rad, int sub)
+{
+ int i;
+ glBegin(GL_TRIANGLE_FAN);
+ glVertex2f(x, y);
+ for(i=0; i<sub; i++) {
+ float t = (float)i / (float)(sub - 1);
+ float theta = t * M_PI * 2.0;
+ glVertex2f(cos(theta) * rad + x, sin(theta) * rad + y);
+ }
+ glEnd();
+}
+
+static void draw_line(float x0, float y0, float x1, float y1, float rad)
+{
+ float dx, dy, rx, ry, len;
+
+ dx = x1 - x0;
+ dy = y1 - y0;
+ len = sqrt(dx * dx + dy * dy);
+
+ rx = rad * dy / len;
+ ry = -rad * dx / len;
+
+ draw_disc(x0, y0, rad, 8);
+ draw_disc(x1, y1, rad, 8);
+
+ glBegin(GL_QUADS);
+ glVertex2f(x0 + rx, y0 + ry);
+ glVertex2f(x1 + rx, y1 + ry);
+ glVertex2f(x1 - rx, y1 - ry);
+ glVertex2f(x0 - rx, y0 - ry);
+ glEnd();
+}
+
void display(void)
{
- int i, nseg;
+ int i;
+ float a[2], b[2], dt = 1.0f / (float)(nverts - 1);
glClear(GL_COLOR_BUFFER_BIT);
- glEnable(GL_BLEND);
- glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
- glLineWidth(2.0);
+ glLineWidth(5.0);
glColor3f(1, 1, 1);
- nseg = LOGOCP_SIZE / 4;
- for(i=0; i<nseg; i++) {
- draw_bezier((float*)(logocp + i * 4), BEZ_SEG);
+ for(i=0; i<nverts-1; i++) {
+ float t0 = (float)i * dt;
+ float t1 = (float)(i + 1) * dt;
+ eval_logo(a, t0);
+ eval_logo(b, t1);
+ draw_line(a[0], a[1], b[0], b[1], 0.02);
}
- glDisable(GL_BLEND);
+ eval_logo(a, 0);
+ eval_logo(b, 1);
+ draw_disc(a[0], a[1], 0.05, 18);
+ draw_disc(b[0], b[1], 0.05, 18);
+
+ glColor3f(0.8, 0, 0);
+ draw_disc(0, 0, 0.14, 24);
glutSwapBuffers();
assert(glGetError() == GL_NO_ERROR);
switch(key) {
case 27:
exit(0);
- }
-}
-
-#define LERP(a, b, t) ((a) + ((b) - (a)) * (t))
-
-void draw_bezier(float *cp, int sub)
-{
- int i;
- float cx[4], cy[4], mx[3], my[3], mmx[2], mmy[2], x, y;
-
- if(sub < 1) sub = 1;
-
- for(i=0; i<4; i++) {
- cx[i] = cp[i * 2] / LOGO_W - 0.5f;
- cy[i] = 0.5f - cp[i * 2 + 1] / LOGO_H;
- }
-
- glBegin(GL_LINE_STRIP);
- for(i=0; i<BEZ_SEG; i++) {
- float t = (float)i / (float)(BEZ_SEG - 1);
-
- mx[0] = LERP(cx[0], cx[1], t);
- my[0] = LERP(cy[0], cy[1], t);
-
- mx[1] = LERP(cx[1], cx[2], t);
- my[1] = LERP(cy[1], cy[2], t);
-
- mx[2] = LERP(cx[2], cx[3], t);
- my[2] = LERP(cy[2], cy[3], t);
- mmx[0] = LERP(mx[0], mx[1], t);
- mmy[0] = LERP(my[0], my[1], t);
-
- mmx[1] = LERP(mx[1], mx[2], t);
- mmy[1] = LERP(my[1], my[2], t);
-
- x = LERP(mmx[0], mmx[1], t);
- y = LERP(mmy[0], mmy[1], t);
-
- glVertex2f(x, y);
+ case '-':
+ nverts -= 8;
+ printf("nverts: %d\n", nverts);
+ glutPostRedisplay();
+ break;
+
+ case '=':
+ nverts += 8;
+ printf("nverts: %d\n", nverts);
+ glutPostRedisplay();
+ break;
}
- glEnd();
}
projects / censuslogo / commitdiff