nuclear@0: #include <stdio.h>
nuclear@0: #include <stdlib.h>
nuclear@0: #include <GL/glut.h>
nuclear@0: 
nuclear@0: #define MAX_POS		512
nuclear@0: 
nuclear@0: typedef struct key {
nuclear@0: 	int pos;
nuclear@0: 	float val;
nuclear@0: 	struct key *next;
nuclear@0: } key_t;
nuclear@0: 
nuclear@0: struct track {
nuclear@0: 	key_t *keys;
nuclear@0: 	int count;
nuclear@0: };
nuclear@0: 
nuclear@0: void redraw(void);
nuclear@0: void draw_curves(void);
nuclear@0: void draw_grad(void);
nuclear@0: 
nuclear@0: void set_val(struct track *track, float pos, float val);
nuclear@0: void rm_val(struct track *track, float pos);
nuclear@0: float get_val(struct track *track, float pos);
nuclear@0: 
nuclear@0: void save(void);
nuclear@0: 
nuclear@0: void key_handler(unsigned char key, int x, int y);
nuclear@0: void skey_handler(int key, int x, int y);
nuclear@0: void mbutton_handler(int bn, int state, int x, int y);
nuclear@0: void drag_handler(int x, int y);
nuclear@0: void reshape_handler(int x, int y);
nuclear@0: 
nuclear@0: int view_xsz = 640;
nuclear@0: int view_ysz = 480;
nuclear@0: 
nuclear@0: struct track tred, tgreen, tblue;
nuclear@0: 
nuclear@0: int main(int argc, char **argv)
nuclear@0: {
nuclear@0: 	glutInit(&argc, argv);
nuclear@0: 	glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);
nuclear@0: 	glutInitWindowSize(view_xsz, view_ysz);
nuclear@0: 	glutCreateWindow("Mindlapse gradiant editor");
nuclear@0: 
nuclear@0: 	glutDisplayFunc(redraw);
nuclear@0: 	glutKeyboardFunc(key_handler);
nuclear@0: 	glutSpecialFunc(skey_handler);
nuclear@0: 	glutMouseFunc(mbutton_handler);
nuclear@0: 	glutMotionFunc(drag_handler);
nuclear@0: 	glutReshapeFunc(reshape_handler);
nuclear@0: 
nuclear@0: 	glClearColor(0, 0, 0, 0);
nuclear@0: 	glEnable(GL_POINT_SMOOTH);
nuclear@0: 
nuclear@0: 	glMatrixMode(GL_PROJECTION);
nuclear@0: 	glOrtho(0, 1, 0, 1, -1, 1);
nuclear@0: 	glMatrixMode(GL_MODELVIEW);
nuclear@0: 
nuclear@0: 	tred.keys = malloc(sizeof *tred.keys);
nuclear@0: 	tred.keys->next = 0;
nuclear@0: 
nuclear@0: 	tgreen.keys = malloc(sizeof *tgreen.keys);
nuclear@0: 	tgreen.keys->next = 0;
nuclear@0: 
nuclear@0: 	tblue.keys = malloc(sizeof *tblue.keys);
nuclear@0: 	tblue.keys->next = 0;
nuclear@0: 
nuclear@0: 	glutMainLoop();
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: void redraw(void)
nuclear@0: {
nuclear@0: 	glClear(GL_COLOR_BUFFER_BIT);
nuclear@0: 
nuclear@0: 	draw_curves();
nuclear@0: 
nuclear@0: 	draw_grad();
nuclear@0: 
nuclear@0: 	glutSwapBuffers();
nuclear@0: }
nuclear@0: 
nuclear@0: void draw_curves(void)
nuclear@0: {
nuclear@0: 	int i;
nuclear@0: 	key_t *ptr;
nuclear@0: 
nuclear@0: 	glLoadIdentity();
nuclear@0: 	glTranslatef(0, 0.25, 0);
nuclear@0: 	glScalef(1, 0.75, 1);
nuclear@0: 
nuclear@0: 	glBegin(GL_LINES);
nuclear@0: 	/* draw grid */
nuclear@0: 	glColor3f(0.5, 0.5, 0.5);
nuclear@0: 	glVertex2f(0, 0); glVertex2f(0, 1);
nuclear@0: 	glVertex2f(1, 0); glVertex2f(1, 1);
nuclear@0: 	glVertex2f(0, 0); glVertex2f(1, 0);
nuclear@0: 	glVertex2f(0, 1); glVertex2f(1, 1);
nuclear@0: 
nuclear@0: 	glVertex2f(0, 0.25); glVertex2f(1, 0.25);
nuclear@0: 	glVertex2f(0, 0.5); glVertex2f(1, 0.5);
nuclear@0: 	glVertex2f(0, 0.75); glVertex2f(1, 0.75);
nuclear@0: 
nuclear@0: 	glVertex2f(0.25, 0); glVertex2f(0.25, 1);
nuclear@0: 	glVertex2f(0.5, 0); glVertex2f(0.5, 1);
nuclear@0: 	glVertex2f(0.75, 0); glVertex2f(0.75, 1);
nuclear@0: 	glEnd();
nuclear@0: 
nuclear@0: 	glEnable(GL_BLEND);
nuclear@0: 	glBlendFunc(GL_ONE, GL_ONE);
nuclear@0: 
nuclear@0: 	glBegin(GL_LINES);
nuclear@0: 	for(i=0; i<3; i++) {
nuclear@0: 		glColor3f(i == 0, i == 1, i == 2);
nuclear@0: 		ptr = (i == 0 ? tred.keys->next : (i == 1 ? tgreen.keys->next : tblue.keys->next));
nuclear@0: 
nuclear@0: 		if(ptr && ptr->pos > 0) {
nuclear@0: 			glVertex2f(0, ptr->val);
nuclear@0: 			glVertex2f(ptr->pos / (float)MAX_POS, ptr->val);
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		while(ptr && ptr->next) {
nuclear@0: 			glVertex2f(ptr->pos / (float)MAX_POS, ptr->val);
nuclear@0: 			glVertex2f(ptr->next->pos / (float)MAX_POS, ptr->next->val);
nuclear@0: 			ptr = ptr->next;
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		if(ptr && ptr->pos != MAX_POS) {
nuclear@0: 			glVertex2f(ptr->pos / (float)MAX_POS, ptr->val);
nuclear@0: 			glVertex2f(1, ptr->val);
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 	glEnd();
nuclear@0: 
nuclear@0: 	glPointSize(5);
nuclear@0: 	glBegin(GL_POINTS);
nuclear@0: 	for(i=0; i<3; i++) {
nuclear@0: 		glColor3f(i == 0, i == 1, i == 2);
nuclear@0: 		ptr = (i == 0 ? tred.keys->next : (i == 1 ? tgreen.keys->next : tblue.keys->next));
nuclear@0: 
nuclear@0: 		while(ptr) {
nuclear@0: 			glVertex2f(ptr->pos / (float)MAX_POS, ptr->val);
nuclear@0: 			ptr = ptr->next;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 	glEnd();
nuclear@0: 
nuclear@0: 	glDisable(GL_BLEND);
nuclear@0: }
nuclear@0: 
nuclear@0: #define GRAD_SAMPLES	MAX_POS
nuclear@0: void draw_grad(void)
nuclear@0: {
nuclear@0: 	int i;
nuclear@0: 
nuclear@0: 	glLoadIdentity();
nuclear@0: 	glScalef(1, 0.25, 1);
nuclear@0: 
nuclear@0: 	glBegin(GL_QUADS);
nuclear@0: 	for(i=0; i<GRAD_SAMPLES-1; i++) {
nuclear@0: 		float t = (float)i / (float)GRAD_SAMPLES;
nuclear@0: 		glColor3f(get_val(&tred, t), get_val(&tgreen, t), get_val(&tblue, t));
nuclear@0: 		glVertex2f(t, 0);
nuclear@0: 		glVertex2f(t, 1);
nuclear@0: 
nuclear@0: 		t = (float)(i + 1) / (float)GRAD_SAMPLES;
nuclear@0: 		glColor3f(get_val(&tred, t), get_val(&tgreen, t), get_val(&tblue, t));
nuclear@0: 		glVertex2f(t, 1);
nuclear@0: 		glVertex2f(t, 0);
nuclear@0: 	}
nuclear@0: 	glEnd();
nuclear@0: }
nuclear@0: 
nuclear@0: void set_val(struct track *tr, float pos, float val)
nuclear@0: {
nuclear@0: 	key_t *nkey;
nuclear@0: 	key_t *ptr = tr->keys;
nuclear@0: 	int ipos = (int)(pos * MAX_POS);
nuclear@0: 
nuclear@0: 	if(!ptr->next || ptr->next->pos > ipos) {
nuclear@0: 		nkey = malloc(sizeof *nkey);
nuclear@0: 		nkey->pos = ipos;
nuclear@0: 		nkey->val = val;
nuclear@0: 		nkey->next = ptr->next;
nuclear@0: 		ptr->next = nkey;
nuclear@0: 		return;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	while(ptr->next && ptr->next->pos < ipos) {
nuclear@0: 		ptr = ptr->next;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	if(ptr->pos == ipos) {
nuclear@0: 		ptr->val = val;
nuclear@0: 	} else {
nuclear@0: 		nkey = malloc(sizeof *nkey);
nuclear@0: 		nkey->pos = ipos;
nuclear@0: 		nkey->val = val;
nuclear@0: 		nkey->next = ptr->next;
nuclear@0: 		ptr->next = nkey;
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: void rm_val(struct track *tr, float pos)
nuclear@0: {
nuclear@0: 	key_t *ptr = tr->keys;
nuclear@0: 	int ipos = (int)(pos * MAX_POS);
nuclear@0: 
nuclear@0: 	while(ptr->next && ptr->next->pos <= ipos) {
nuclear@0: 		if(ptr->next->pos == ipos) {
nuclear@0: 			key_t *tmp = ptr->next;
nuclear@0: 			ptr->next = ptr->next->next;
nuclear@0: 			free(tmp);
nuclear@0: 			return;
nuclear@0: 		}
nuclear@0: 		ptr = ptr->next;
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: float get_val(struct track *tr, float pos)
nuclear@0: {
nuclear@0: 	float t;
nuclear@0: 	key_t *ptr = tr->keys->next;
nuclear@0: 	int ipos = (int)(pos * MAX_POS);
nuclear@0: 
nuclear@0: 	if(!ptr) {
nuclear@0: 		return 0.0;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	while(ptr && ptr->pos <= ipos) {
nuclear@0: 		if(ptr->pos == ipos || !ptr->next) {
nuclear@0: 			return ptr->val;
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		if(ptr->next->pos > ipos) {
nuclear@0: 			t = (float)(ipos - ptr->pos) / (float)(ptr->next->pos - ptr->pos);
nuclear@0: 			return ptr->val + (ptr->next->val - ptr->val) * t;
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		ptr = ptr->next;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	return tr->keys->next->val;
nuclear@0: }
nuclear@0: 
nuclear@0: void clear_track(struct track *tr)
nuclear@0: {
nuclear@0: 	key_t *ptr = tr->keys->next;
nuclear@0: 	while(ptr) {
nuclear@0: 		key_t *tmp = ptr;
nuclear@0: 		ptr = ptr->next;
nuclear@0: 		free(tmp);
nuclear@0: 	}
nuclear@0: 	tr->keys->next = 0;
nuclear@0: }
nuclear@0: 
nuclear@0: 
nuclear@0: #define IMG_X	256
nuclear@0: #define FNAME	"grad.ppm"
nuclear@0: void save(void)
nuclear@0: {
nuclear@0: 	int i;
nuclear@0: 	FILE *fp;
nuclear@0: 
nuclear@0: 	if(!(fp = fopen(FNAME, "wb"))) {
nuclear@0: 		perror("failed to write " FNAME);
nuclear@0: 		return;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	fprintf(fp, "P6\n%d %d\n255\n", IMG_X, 1);
nuclear@0: 
nuclear@0: 	for(i=0; i<IMG_X; i++) {
nuclear@0: 		float t = (float)i / (float)IMG_X;
nuclear@0: 		int r = get_val(&tred, t) * 255.0;
nuclear@0: 		int g = get_val(&tgreen, t) * 255.0;
nuclear@0: 		int b = get_val(&tblue, t) * 255.0;
nuclear@0: 
nuclear@0: 		fputc(r, fp);
nuclear@0: 		fputc(g, fp);
nuclear@0: 		fputc(b, fp);
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	fclose(fp);
nuclear@0: }
nuclear@0: 
nuclear@0: 
nuclear@0: void key_handler(unsigned char key, int x, int y)
nuclear@0: {
nuclear@0: 	skey_handler(key, x, y);
nuclear@0: }
nuclear@0: 
nuclear@0: void skey_handler(int key, int x, int y)
nuclear@0: {
nuclear@0: 	switch(key) {
nuclear@0: 	case 27:
nuclear@0: 		exit(0);
nuclear@0: 
nuclear@0: 	case 's':
nuclear@0: 	case 'S':
nuclear@0: 		save();
nuclear@0: 		break;
nuclear@0: 
nuclear@0: 	case 'c':
nuclear@0: 		clear_track(&tred);
nuclear@0: 		clear_track(&tgreen);
nuclear@0: 		clear_track(&tblue);
nuclear@0: 		glutPostRedisplay();
nuclear@0: 		break;
nuclear@0: 
nuclear@0: 	default:
nuclear@0: 		break;
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: static int px, py;
nuclear@0: static float ppos, pval;
nuclear@0: static struct track *tr;
nuclear@0: 
nuclear@0: void mbutton_handler(int bn, int state, int x, int y)
nuclear@0: {
nuclear@0: 	float pos, val;
nuclear@0: 
nuclear@0: 	pos = (float)x / (float)view_xsz;
nuclear@0: 	val = 1.0 - (float)y / (float)(view_ysz - view_ysz / 4.0);
nuclear@0: 
nuclear@0: 	if(bn == GLUT_LEFT_BUTTON) {
nuclear@0: 		tr = &tred;
nuclear@0: 	} else if(bn == GLUT_MIDDLE_BUTTON) {
nuclear@0: 		tr = &tgreen;
nuclear@0: 	} else if(bn == GLUT_RIGHT_BUTTON) {
nuclear@0: 		tr = &tblue;
nuclear@0: 	} else {
nuclear@0: 		return;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	if(glutGetModifiers() & GLUT_ACTIVE_CTRL) {
nuclear@0: 		tr = 0;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	if(state == 0) {
nuclear@0: 		px = x;
nuclear@0: 		py = y;
nuclear@0: 		ppos = pos;
nuclear@0: 		pval = val;
nuclear@0: 	} else {
nuclear@0: 		if(px == -1 || abs(x - px) > 2 || abs(y - py) > 2) {
nuclear@0: 			return;
nuclear@0: 		}
nuclear@0: 		if(val < 0.0 || val > 1.0) return;
nuclear@0: 
nuclear@0: 
nuclear@0: 		if(glutGetModifiers() & GLUT_ACTIVE_SHIFT) {
nuclear@0: 			if(tr) {
nuclear@0: 				rm_val(tr, pos);
nuclear@0: 			} else {
nuclear@0: 				rm_val(&tred, pos);
nuclear@0: 				rm_val(&tgreen, pos);
nuclear@0: 				rm_val(&tblue, pos);
nuclear@0: 			}
nuclear@0: 		} else {
nuclear@0: 			if(tr) {
nuclear@0: 				set_val(tr, pos, val);
nuclear@0: 			} else {
nuclear@0: 				set_val(&tred, pos, val);
nuclear@0: 				set_val(&tgreen, pos, val);
nuclear@0: 				set_val(&tblue, pos, val);
nuclear@0: 			}
nuclear@0: 		}
nuclear@0: 
nuclear@0: 		px = -1;
nuclear@0: 		py = -1;
nuclear@0: 		glutPostRedisplay();
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: void drag_handler(int x, int y)
nuclear@0: {
nuclear@0: 	float pos = (float)x / (float)view_xsz;
nuclear@0: 	float val = 1.0 - (float)y / (float)(view_ysz - view_ysz / 4.0);
nuclear@0: 
nuclear@0: 	if(pos < 0.0) pos = 0.0;
nuclear@0: 	if(pos > 1.0) pos = 1.0;
nuclear@0: 	if(val < 0.0) val = 0.0;
nuclear@0: 	if(val > 1.0) val = 1.0;
nuclear@0: 
nuclear@0: 	if(tr) {
nuclear@0: 		rm_val(tr, ppos);
nuclear@0: 		rm_val(tr, ppos - 1.0 / (float)view_xsz);
nuclear@0: 		rm_val(tr, ppos + 1.0 / (float)view_xsz);
nuclear@0: 		set_val(tr, pos, val);
nuclear@0: 	} else {
nuclear@0: 		rm_val(&tred, ppos);
nuclear@0: 		rm_val(&tgreen, ppos);
nuclear@0: 		rm_val(&tblue, ppos);
nuclear@0: 		rm_val(&tred, ppos - 1.0 / (float)view_xsz);
nuclear@0: 		rm_val(&tgreen, ppos - 1.0 / (float)view_xsz);
nuclear@0: 		rm_val(&tblue, ppos - 1.0 / (float)view_xsz);
nuclear@0: 		rm_val(&tred, ppos + 1.0 / (float)view_xsz);
nuclear@0: 		rm_val(&tgreen, ppos + 1.0 / (float)view_xsz);
nuclear@0: 		rm_val(&tblue, ppos + 1.0 / (float)view_xsz);
nuclear@0: 		set_val(&tred, pos, val);
nuclear@0: 		set_val(&tgreen, pos, val);
nuclear@0: 		set_val(&tblue, pos, val);
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	ppos = pos;
nuclear@0: 	pval = val;
nuclear@0: 
nuclear@0: 	glutPostRedisplay();
nuclear@0: }
nuclear@0: 
nuclear@0: void reshape_handler(int x, int y)
nuclear@0: {
nuclear@0: 	view_xsz = x;
nuclear@0: 	view_ysz = y;
nuclear@0: 
nuclear@0: 	glViewport(0, 0, x, y);
nuclear@0: }