*
* TODO:
*
- * - Add code to add boxes
- * - Add circle object
+ * - Add code to add boxes
+ * - Add circle object
+ * - Try out this idea: make constraint solver take mean of all
+ * corrections at the end instead of meaning as it goes.
*/
#include <gtk/gtk.h>
#include <cairo-xlib.h>
#include <gdk/gdkx.h>
#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
#include <math.h>
-const double ground_friction = 0.1, ground_level = 400;
-const double box_left = 200, box_top = 200, box_bottom = 210;
-const double elasticity = 0.7;
-const double edge_fuzz = 1;
+const double ground_level = 500;
+const double elasticity = 0.8;
typedef struct _xy_pair Point;
typedef struct _xy_pair Vector;
typedef struct _Object Object;
typedef struct _Stick Stick;
+typedef struct _String String;
+typedef struct _Spring Spring;
+typedef struct _OffsetSpring OffsetSpring;
+typedef struct _Polygon Polygon;
typedef struct _Offset Offset;
typedef struct _Model Model;
int length;
};
+struct _String {
+ Object *a, *b;
+ int length;
+};
+
struct _Offset {
+ int num_objects;
+ Object **objects;
+ int dx, dy;
+};
+
+struct _Spring {
+ Object *a, *b;
+ int length;
+};
+
+struct _OffsetSpring {
Object *a, *b;
int dx, dy;
};
+struct _Polygon {
+ int num_points;
+ Point *points;
+ Vector *normals;
+ int edge;
+};
+
struct _Model {
int num_objects;
Object *objects;
int num_sticks;
Stick *sticks;
+ int num_strings;
+ String *strings;
int num_offsets;
Offset *offsets;
+ int num_springs;
+ Spring *springs;
+ int num_offset_springs;
+ OffsetSpring *offset_springs;
+ int num_polygons;
+ Polygon *polygons;
double k;
double friction;
double theta;
};
+static void
+polygon_init (Polygon *p, int num_points, ...)
+{
+ double dx, dy, length;
+ int i, j;
+ va_list ap;
+
+ /* Polygons are defined counter-clock-wise in a coordinate system
+ * with the y-axis pointing down. */
+
+ va_start (ap, num_points);
+ p->num_points = num_points;
+ p->points = g_new (Point, num_points);
+
+ for (i = 0; i < num_points; i++) {
+ p->points[i].x = va_arg (ap, double);
+ p->points[i].y = va_arg (ap, double);
+ }
+ va_end (ap);
+
+ p->normals = g_new (Vector, p->num_points);
+ /* Compute outward pointing normals. p->normals[i] is the normal
+ * for the edged between p->points[i] and p->points[i + 1]. */
+ for (i = 0; i < p->num_points; i++) {
+ j = (i + 1) % p->num_points;
+ dx = p->points[j].x - p->points[i].x;
+ dy = p->points[j].y - p->points[i].y;
+ length = sqrt (dx * dx + dy * dy);
+ p->normals[i].x = -dy / length;
+ p->normals[i].y = dx / length;
+ }
+}
+
+static void
+polygon_init_diamond (Polygon *polygon, double x, double y)
+{
+ return polygon_init (polygon, 5,
+ x, y,
+ x + 10, y + 40,
+ x + 90, y + 40,
+ x + 100, y,
+ x + 50, y - 20);
+}
+
+static void
+polygon_init_rectangle (Polygon *polygon, double x0, double y0,
+ double x1, double y1)
+{
+ return polygon_init (polygon, 4, x0, y0, x0, y1, x1, y1, x1, y0);
+}
+
+static void
+model_init_polygons (Model *model)
+{
+ const int num_polygons = 5;
+
+ model->polygons = g_new (Polygon, num_polygons);
+ polygon_init_diamond (&model->polygons[0], 250, 300);
+ polygon_init_diamond (&model->polygons[1], 400, 150);
+ polygon_init_rectangle (&model->polygons[2], -100, 200, 200, 250);
+ polygon_init_rectangle (&model->polygons[3], -200, ground_level,
+ 1200, ground_level + 400);
+
+ polygon_init_rectangle (&model->polygons[4], 300, 320, 400, 350);
+
+ model->num_polygons = num_polygons;
+}
+
static void
model_init_snake (Model *model)
{
const int num_sticks = num_objects * 2 - 3;
int i;
+ memset (model, 0, sizeof *model);
model->objects = g_new (Object, num_objects);
model->num_objects = num_objects;
model->sticks = g_new (Stick, num_sticks);
model->num_sticks = num_sticks;
- model->num_offsets = 0;
+ model_init_polygons (model);
for (i = 0; i < num_objects; i++) {
model->objects[i].position.x = random() % 200 + 20;
model->objects[i].position.y = random() % 200 + 20;
model->objects[i].previous_position.x = random() % 200 + 20;
model->objects[i].previous_position.y = random() % 200 + 20;
+ model->objects[i].mass = 1;
if (i + 1 < num_objects) {
model->sticks[i * 2].a = &model->objects[i];
{
const int num_objects = 20;
const int num_sticks = num_objects - 1;
- const int stick_length = 5;
+ const int stick_length = 10;
int i;
+ memset (model, 0, sizeof *model);
model->objects = g_new (Object, num_objects);
model->num_objects = num_objects;
model->sticks = g_new (Stick, num_sticks);
model->num_sticks = num_sticks;
- model->offsets = NULL;
- model->num_offsets = 0;
+ model_init_polygons (model);
for (i = 0; i < num_objects; i++) {
model->objects[i].position.x = 200;
model->objects[i].position.y = 40 + i * stick_length;
model->objects[i].previous_position.x = 200;
model->objects[i].previous_position.y = 40 + i * stick_length;
+ model->objects[i].mass = 1;
if (i + 1 < num_objects) {
model->sticks[i].a = &model->objects[i];
double x, y;
int i, j, index, stick_index;
+ memset (model, 0, sizeof *model);
model->objects = g_new (Object, num_objects);
model->num_objects = num_objects;
model->sticks = g_new (Stick, num_sticks);
model->num_sticks = num_sticks;
- model->offsets = g_new (Offset, num_ropes - 1);
- model->num_offsets = num_ropes - 1;
+ model->offsets = g_new (Offset, 1);
+ model->num_offsets = 1;
+ model_init_polygons (model);
+
+ model->offsets[0].num_objects = num_ropes;
+ model->offsets[0].objects = g_new (Object *, num_ropes);
+ model->offsets[0].dx = rope_offset;
+ model->offsets[0].dy = 0;
for (i = 0; i < num_ropes; i++) {
for (j = 0; j < num_rope_objects; j++) {
model->objects[index].position.y = y;
model->objects[index].previous_position.x = x;
model->objects[index].previous_position.y = y;
+ model->objects[i].mass = 1;
if (j + 1 < num_rope_objects) {
stick_index = i * (num_rope_objects - 1) + j;
}
}
- if (i + 1 < num_ropes) {
- model->offsets[i].a = &model->objects[i * num_rope_objects];
- model->offsets[i].b = &model->objects[(i + 1) * num_rope_objects];
- model->offsets[i].dx = rope_offset;
- model->offsets[i].dy = 0;
+ model->offsets[0].objects[i] = &model->objects[i * num_rope_objects];
+ }
+
+ model->anchor_object = NULL;
+}
+
+static void
+model_init_grid (Model *model)
+{
+ const int num_ropes = 4;
+ const int num_rope_objects = 4;
+ const int num_objects = num_ropes * num_rope_objects;
+ const int num_strings = num_ropes * (num_rope_objects - 1) +
+ (num_ropes - 1) * num_rope_objects;
+ const int string_length = 20;
+ const int rope_offset = 20;
+ double x, y;
+ int i, j, index, string_index;
+
+ memset (model, 0, sizeof *model);
+ model->objects = g_new (Object, num_objects);
+ model->num_objects = num_objects;
+ model->strings = g_new (String, num_strings);
+ model->num_strings = num_strings;
+ model->offsets = g_new (Offset, 1);
+ model->num_offsets = 1;
+ model_init_polygons (model);
+
+ model->offsets[0].num_objects = num_ropes;
+ model->offsets[0].objects = g_new (Object *, num_ropes);
+ model->offsets[0].dx = rope_offset;
+ model->offsets[0].dy = 0;
+
+ for (i = 0; i < num_ropes; i++) {
+ for (j = 0; j < num_rope_objects; j++) {
+ x = 200 + i * rope_offset;
+ y = 40 + j * string_length;
+ index = i * num_rope_objects + j;
+ model->objects[index].position.x = x;
+ model->objects[index].position.y = y;
+ model->objects[index].previous_position.x = x;
+ model->objects[index].previous_position.y = y;
+ model->objects[index].mass = 1;
+
+ if (i + 1 < num_ropes) {
+ string_index = i * num_rope_objects + j;
+ model->strings[string_index].a = &model->objects[index];
+ model->strings[string_index].b = &model->objects[index + num_rope_objects];
+ model->strings[string_index].length = string_length;
+ }
+
+ if (j + 1 < num_rope_objects) {
+ string_index =
+ (num_ropes - 1) * num_rope_objects + i * (num_rope_objects - 1) + j;
+ model->strings[string_index].a = &model->objects[index];
+ model->strings[string_index].b = &model->objects[index + 1];
+ model->strings[string_index].length = string_length;
+ }
}
+
+ model->offsets[0].objects[i] = &model->objects[i * num_rope_objects];
}
model->anchor_object = NULL;
}
+static void
+model_init_molecule (Model *model)
+{
+ const int num_objects = 8;
+ const int num_springs = num_objects * 2;
+ const int spring_length = 50;
+ int i;
+
+ memset (model, 0, sizeof *model);
+ model->objects = g_new (Object, num_objects);
+ model->num_objects = num_objects;
+ model->springs = g_new (Spring, num_springs);
+ model->num_springs = num_springs;
+ model->k = 0.2;
+
+ for (i = 0; i < num_objects; i++) {
+ model->objects[i].position.x = 200 + i * 20;
+ model->objects[i].position.y = 200;
+ model->objects[i].previous_position.x = 200 + i * 20;
+ model->objects[i].previous_position.y = 200;
+ model->objects[i].mass = 0;
+ }
+
+ for (i = 0; i < num_objects; i++) {
+ model->springs[i * 2].a = &model->objects[i];
+ model->springs[i * 2].b = &model->objects[(i + 1) % num_objects];
+ model->springs[i * 2].length = spring_length;
+ model->springs[i * 2 + 1].a = &model->objects[i];
+ model->springs[i * 2 + 1].b = &model->objects[(i + 2) % num_objects];
+ model->springs[i * 2 + 1].length = spring_length;
+ }
+}
+
+
+static void
+model_init_wobbly (Model *model)
+{
+ const int width = 6, height = 6;
+ const int num_objects = width * height;
+ const int num_offset_springs = (width - 1) * height + width * (height - 1);
+ const int distance = 30;
+ double x, y;
+ int i, j, object_index, spring_index;
+
+ memset (model, 0, sizeof *model);
+ model->objects = g_new (Object, num_objects);
+ model->num_objects = num_objects;
+ model->offset_springs = g_new (OffsetSpring, num_offset_springs);
+ model->num_offset_springs = num_offset_springs;
+ model->k = 0.6;
+
+ model_init_polygons (model);
+
+ object_index = 0;
+ spring_index = 0;
+ for (i = 0; i < width; i++) {
+ for (j = 0; j < height; j++) {
+ x = 200 + i * distance;
+ y = 40 + j * distance;
+ model->objects[object_index].position.x = x;
+ model->objects[object_index].position.y = y;
+ model->objects[object_index].previous_position.x = x;
+ model->objects[object_index].previous_position.y = y;
+ model->objects[object_index].mass = 0.3;
+
+ if (i + 1 < width) {
+ model->offset_springs[spring_index].a = &model->objects[object_index];
+ model->offset_springs[spring_index].b = &model->objects[object_index + height];
+ model->offset_springs[spring_index].dx = distance;
+ model->offset_springs[spring_index].dy = 0;
+ spring_index++;
+ }
+
+ if (j + 1 < height) {
+ model->offset_springs[spring_index].a = &model->objects[object_index];
+ model->offset_springs[spring_index].b = &model->objects[object_index + 1];
+ model->offset_springs[spring_index].dx = 0;
+ model->offset_springs[spring_index].dy = distance;
+ spring_index++;
+ }
+
+ object_index++;
+ }
+ }
+}
+
+
static void
model_fini (Model *model)
{
g_free (model->objects);
- model->objects = NULL;
- model->num_objects = 0;
g_free (model->sticks);
- model->sticks = NULL;
- model->sticks = 0;
+ g_free (model->strings);
g_free (model->offsets);
- model->offsets = NULL;
- model->num_offsets = 0;
+ memset (model, 0, sizeof *model);
}
static void
model_accumulate_forces (Model *model)
{
int i;
+ double x, y, dx, dy, distance, displacement;
+ Point middle;
+ Vector u;
for (i = 0; i < model->num_objects; i++) {
model->objects[i].force.x = 0;
- model->objects[i].force.y = 0;
+ model->objects[i].force.y = 3 * model->objects[i].mass;
+ }
+
+ for (i = 0; i < model->num_springs; i++) {
+ x = model->springs[i].a->position.x;
+ y = model->springs[i].a->position.y;
+ dx = model->springs[i].b->position.x - x;
+ dy = model->springs[i].b->position.y - y;
+ distance = sqrt (dx * dx + dy * dy);
+ u.x = dx / distance;
+ u.y = dy / distance;
+ displacement = distance - model->springs[i].length;
+ model->springs[i].a->force.x += u.x * model->k * displacement;
+ model->springs[i].a->force.y += u.y * model->k * displacement;
+ model->springs[i].b->force.x -= u.x * model->k * displacement;
+ model->springs[i].b->force.y -= u.y * model->k * displacement;
+ }
+
+ for (i = 0; i < model->num_offset_springs; i++) {
+ middle.x =
+ (model->offset_springs[i].a->position.x +
+ model->offset_springs[i].b->position.x) / 2;
+ middle.y =
+ (model->offset_springs[i].a->position.y +
+ model->offset_springs[i].b->position.y) / 2;
+
+ x = middle.x - model->offset_springs[i].dx / 2;
+ y = middle.y - model->offset_springs[i].dy / 2;
+
+ dx = x - model->offset_springs[i].a->position.x;
+ dy = y - model->offset_springs[i].a->position.y;
+
+ model->offset_springs[i].a->force.x += dx * model->k;
+ model->offset_springs[i].a->force.y += dy * model->k;
+ model->offset_springs[i].b->force.x -= dx * model->k;
+ model->offset_springs[i].b->force.y -= dy * model->k;
}
}
y = o->position.y;
o->position.x =
- x + (x - o->previous_position.x) + o->force.x * step * step;
+ x + 0.9 * (x - o->previous_position.x) + o->force.x * step * step;
o->position.y =
- y + (y - o->previous_position.y) + o->force.y * step * step;
+ y + 0.9 * (y - o->previous_position.y) + o->force.y * step * step;
o->previous_position.x = x;
o->previous_position.y = y;
}
}
+/* The square root in the distance computation for the string and
+ * stick constraints can be aproximated using Newton:
+ *
+ * distance =
+ * (model->sticks[i].length +
+ * (dx * dx + dy * dy) / model->sticks[i].length) / 2;
+ *
+ * This works really well, since the constraints aren't typically
+ * violated much. Thus, the distance is really close to the stick
+ * length, which then makes a good initial guess. However, the
+ * approximation seems to be slower that just calling sqrt()...
+ */
+
+static inline double
+estimate_distance (double dx, double dy, double r)
+{
+#ifdef APPROXIMATE_SQUARE_ROOTS
+ return (r + (dx * dx + dy * dy) / r) / 2;
+#else
+ return sqrt (dx * dx + dy * dy);
+#endif
+}
+
+static int
+polygon_contains_point (Polygon *polygon, Point *point)
+{
+ int i;
+ double dx, dy;
+
+ for (i = 0; i < polygon->num_points; i++) {
+ dx = point->x - polygon->points[i].x;
+ dy = point->y - polygon->points[i].y;
+
+ if (polygon->normals[i].x * dx + polygon->normals[i].y * dy >= 0)
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+static void
+polygon_reflect_object (Polygon *polygon, Object *object)
+{
+ int i, edge;
+ double d, distance;
+ Vector *n;
+
+ distance = -1000;
+ for (i = 0; i < polygon->num_points; i++) {
+ d = polygon->normals[i].x * (object->position.x - polygon->points[i].x) +
+ polygon->normals[i].y * (object->position.y - polygon->points[i].y);
+
+ if (d > distance) {
+ distance = d;
+ edge = i;
+ polygon->edge = i;
+ n = &polygon->normals[i];
+ }
+ }
+
+ object->position.x -= (1 + elasticity) * distance * n->x;
+ object->position.y -= (1 + elasticity) * distance * n->y;
+
+ distance =
+ n->x * (object->previous_position.x - polygon->points[edge].x) +
+ n->y * (object->previous_position.y - polygon->points[edge].y);
+
+ object->previous_position.x -= (1 + elasticity) * distance * n->x;
+ object->previous_position.y -= (1 + elasticity) * distance * n->y;
+}
+
+static void
+model_constrain_polygon (Model *model, Polygon *polygon)
+{
+ int i;
+
+ for (i = 0; i < model->num_objects; i++) {
+ if (polygon_contains_point (polygon, &model->objects[i].position))
+ polygon_reflect_object (polygon, &model->objects[i]);
+ }
+}
+
+static void
+model_constrain_offset (Model *model, Offset *offset)
+{
+ double x, y;
+ int i;
+
+ x = 0;
+ y = 0;
+ for (i = 0; i < offset->num_objects; i++) {
+ x += offset->objects[i]->position.x;
+ y += offset->objects[i]->position.y;
+ }
+
+ x = x / offset->num_objects - offset->dx * (offset->num_objects - 1) / 2;
+ y = y / offset->num_objects - offset->dy * (offset->num_objects - 1) / 2;
+
+ for (i = 0; i < offset->num_objects; i++) {
+ offset->objects[i]->position.x = x + offset->dx * i;
+ offset->objects[i]->position.y = y + offset->dy * i;
+ }
+}
+
static void
-model_constrain (Model *model, double step)
+model_constrain (Model *model)
{
double dx, dy, x, y, distance, fraction;
int i;
model->anchor_object->previous_position.y = model->anchor_position.y;
}
- /* FIXME: this should be "is point inside box" test instead. Figure
- * out from previous_position which edge the point has passed
- * through and reflect in that. */
- for (i = 0; i < model->num_objects; i++) {
- x = model->objects[i].position.x;
- y = model->objects[i].position.y;
- if (box_top - edge_fuzz <= y &&
- model->objects[i].previous_position.y <= box_top + edge_fuzz &&
- x < box_left) {
- model->objects[i].position.y = box_top - (y - box_top) * elasticity;
- model->objects[i].previous_position.y =
- box_top - (model->objects[i].previous_position.y - box_top) * elasticity;
- }
+ /* String constraints. */
+ for (i = 0; i < model->num_strings; i++) {
+ x = model->strings[i].a->position.x;
+ y = model->strings[i].a->position.y;
+ dx = model->strings[i].b->position.x - x;
+ dy = model->strings[i].b->position.y - y;
+ distance = estimate_distance (dx, dy, model->strings[i].length);
+ if (distance < model->strings[i].length)
+ continue;
+ fraction = (distance - model->strings[i].length) / distance / 2;
+ model->strings[i].a->position.x = x + dx * fraction;
+ model->strings[i].a->position.y = y + dy * fraction;
+ model->strings[i].b->position.x = x + dx * (1 - fraction);
+ model->strings[i].b->position.y = y + dy * (1 - fraction);
}
- /* Ground collision detection constraints. This puts a ground level
- * in to make sure the points don't fall off the screen. */
- for (i = 0; i < model->num_objects; i++) {
- x = model->objects[i].position.x;
- y = model->objects[i].position.y;
-
- if (model->objects[i].position.y > ground_level) {
- model->objects[i].position.y =
- ground_level - (model->objects[i].position.y - ground_level) * elasticity;
- model->objects[i].previous_position.y =
- ground_level - (model->objects[i].previous_position.y - ground_level) * elasticity;
-
- /* Friction on impact */
- model->objects[i].position.x =
- model->objects[i].position.x * (1 - ground_friction) +
- model->objects[i].previous_position.x * ground_friction;
- }
- }
-
- /* Offset constraints. */
- for (i = 0; i < model->num_offsets; i++) {
- x = (model->offsets[i].a->position.x + model->offsets[i].b->position.x) / 2;
- y = (model->offsets[i].a->position.y + model->offsets[i].b->position.y) / 2;
- model->offsets[i].a->position.x = x - model->offsets[i].dx / 2;
- model->offsets[i].a->position.y = y - model->offsets[i].dy / 2;
- model->offsets[i].b->position.x = x + model->offsets[i].dx / 2;
- model->offsets[i].b->position.y = y + model->offsets[i].dy / 2;
- }
-
-#if 1
/* Stick constraints. */
for (i = 0; i < model->num_sticks; i++) {
x = model->sticks[i].a->position.x;
y = model->sticks[i].a->position.y;
dx = model->sticks[i].b->position.x - x;
dy = model->sticks[i].b->position.y - y;
- distance = sqrt (dx * dx + dy * dy);
+ distance = estimate_distance (dx, dy, model->sticks[i].length);
fraction = (distance - model->sticks[i].length) / distance / 2;
model->sticks[i].a->position.x = x + dx * fraction;
model->sticks[i].a->position.y = y + dy * fraction;
model->sticks[i].b->position.x = x + dx * (1 - fraction);
model->sticks[i].b->position.y = y + dy * (1 - fraction);
}
-#else
- /* Stick constraints, without square roots. */
- squared = stick_length * stick_length;
- for (i = 0; i < model->num_objects - 1; i++) {
- j = i + 1;
- x = model->objects[i].position.x;
- y = model->objects[i].position.y;
- dx = model->objects[j].position.x - x;
- dy = model->objects[j].position.y - y;
- fraction = squared / (dx * dx + dy * dy + squared) - 0.5;
- model->objects[i].position.x = x + dx * fraction;
- model->objects[i].position.y = y + dy * fraction;
- model->objects[j].position.x = x + dx * (1 - fraction);
- model->objects[j].position.y = y + dy * (1 - fraction);
- }
-#endif
+
+ /* Offset constraints. */
+ for (i = 0; i < model->num_offsets; i++)
+ model_constrain_offset (model, &model->offsets[i]);
+
+ /* Polygon constraints. */
+ for (i = 0; i < model->num_polygons; i++)
+ model_constrain_polygon (model, &model->polygons[i]);
}
static void
model_accumulate_forces (model);
model_integrate (model, delta_t);
- for (i = 0; i < 20; i++)
- model_constrain (model, delta_t);
+ for (i = 0; i < 50; i++)
+ model_constrain (model);
model->theta += delta_t;
}
}
static void
-draw_offsets (cairo_t *cr,
+draw_strings (cairo_t *cr,
Model *model,
Color *color)
{
int i;
+ cairo_set_source_rgba (cr, color->red, color->green, color->blue, 1);
+ cairo_new_path (cr);
+ cairo_set_line_width (cr, 1);
+ cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
+ cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
+
+ for (i = 0; i < model->num_strings; i++) {
+ cairo_move_to (cr,
+ model->strings[i].a->position.x,
+ model->strings[i].a->position.y);
+ cairo_line_to (cr,
+ model->strings[i].b->position.x,
+ model->strings[i].b->position.y);
+ }
+
+ cairo_stroke (cr);
+}
+
+static void
+draw_offsets (cairo_t *cr,
+ Model *model,
+ Color *color)
+{
+ int i, j;
+
cairo_set_source_rgba (cr, color->red, color->green, color->blue, 0.5);
cairo_new_path (cr);
cairo_set_line_width (cr, 4);
cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
for (i = 0; i < model->num_offsets; i++) {
+ for (j = 0; j < model->offsets[i].num_objects; j++) {
+ cairo_line_to (cr,
+ model->offsets[i].objects[j]->position.x,
+ model->offsets[i].objects[j]->position.y);
+ }
+ cairo_stroke (cr);
+ }
+
+}
+
+static void
+draw_springs (cairo_t *cr,
+ Model *model,
+ Color *color)
+{
+ int i;
+
+ cairo_set_source_rgba (cr, color->red, color->green, color->blue, 0.4);
+ cairo_new_path (cr);
+ cairo_set_line_width (cr, 2);
+ cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
+ cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
+
+ for (i = 0; i < model->num_springs; i++) {
cairo_move_to (cr,
- model->offsets[i].a->position.x,
- model->offsets[i].a->position.y);
+ model->springs[i].a->position.x,
+ model->springs[i].a->position.y);
cairo_line_to (cr,
- model->offsets[i].b->position.x,
- model->offsets[i].b->position.y);
+ model->springs[i].b->position.x,
+ model->springs[i].b->position.y);
}
cairo_stroke (cr);
}
static void
-draw_constraints (cairo_t *cr,
- Model *model,
- Color *color)
+draw_offset_springs (cairo_t *cr,
+ Model *model,
+ Color *color)
{
- cairo_set_source_rgba (cr, color->red, color->green, color->blue, 0.5);
+ int i;
+
+ cairo_set_source_rgba (cr, color->red, color->green, color->blue, 0.4);
+ cairo_new_path (cr);
+ cairo_set_line_width (cr, 2);
+ cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
+ cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
- cairo_move_to (cr, 0, ground_level);
- cairo_line_to (cr, 1500, ground_level);
- cairo_line_to (cr, 1500, ground_level + 10);
- cairo_line_to (cr, 0, ground_level + 10);
- cairo_close_path (cr);
+ for (i = 0; i < model->num_offset_springs; i++) {
+ cairo_move_to (cr,
+ model->offset_springs[i].a->position.x,
+ model->offset_springs[i].a->position.y);
+ cairo_line_to (cr,
+ model->offset_springs[i].b->position.x,
+ model->offset_springs[i].b->position.y);
+ }
+
+ cairo_stroke (cr);
+}
+
+static void
+draw_polygons (cairo_t *cr, Model *model, Color *color)
+{
+ Polygon *p;
+ int i, j;
- cairo_move_to (cr, 0, box_top);
- cairo_line_to (cr, box_left, box_top);
- cairo_line_to (cr, box_left, box_bottom);
- cairo_line_to (cr, 0, box_bottom);
- cairo_close_path (cr);
+ for (i = 0; i < model->num_polygons; i++) {
+ p = &model->polygons[i];
+ cairo_set_source_rgba (cr, color->red, color->green, color->blue, 0.4);
+
+ for (j = 0; j < p->num_points; j++)
+ cairo_line_to (cr, p->points[j].x, p->points[j].y);
+ cairo_close_path (cr);
+ }
cairo_fill (cr);
+
}
static void
{
int i;
+ cairo_set_source_rgba (cr, color->red, color->green, color->blue, 0.4);
for (i = 0; i < model->num_objects; i++) {
+ cairo_arc (cr, model->objects[i].position.x,
+ model->objects[i].position.y,
+ 3, 0, 2*M_PI);
+ cairo_fill (cr);
}
}
static Color blue = { 0, 0, 1 };
+static Color green = { 0, 1, 0 };
static Color red = { 1, 0, 0 };
static Color black = { 0, 0, 0 };
-static Color white = { 1, 1, 1 };
-static gboolean
-expose_event (GtkWidget *widget,
- GdkEventExpose *event,
- gpointer data)
+typedef struct _Closure Closure;
+struct _Closure {
+ GtkWidget *drawing_area;
+ GtkWidget *fps_label;
+ Model *model;
+ int frame_count;
+ int i;
+ struct timeval start;
+};
+
+static void
+draw_model (GtkWidget *widget, Model *model)
{
- Model *model = data;
cairo_t *cr;
cr = gdk_cairo_create (widget->window);
cairo_set_source_rgb (cr, 1, 1, 1);
cairo_paint (cr);
- draw_constraints (cr, model, &red);
+ draw_polygons (cr, model, &blue);
draw_sticks (cr, model, &black);
+ draw_strings (cr, model, &green);
+ draw_springs (cr, model, &black);
draw_offsets (cr, model, &blue);
- draw_objects (cr, model, &white);
+ draw_offset_springs (cr, model, &blue);
+ draw_objects (cr, model, &red);
cairo_destroy (cr);
+}
+
+static gboolean
+expose_event (GtkWidget *widget,
+ GdkEventExpose *event,
+ gpointer data)
+{
+ Closure *closure = data;
+
+ draw_model (widget, closure->model);
return TRUE;
}
GdkEventButton *event,
gpointer data)
{
- Model *model = data;
+ Closure *closure = data;
if (event->button != 1)
return TRUE;
- model->anchor_position.x = event->x;
- model->anchor_position.y = event->y;
- model->anchor_object = model_find_nearest (model, event->x, event->y);
+ closure->model->anchor_position.x = event->x;
+ closure->model->anchor_position.y = event->y;
+ closure->model->anchor_object = model_find_nearest (closure->model,
+ event->x, event->y);
return TRUE;
}
GdkEventButton *event,
gpointer data)
{
- Model *model = data;
+ Closure *closure = data;
if ((event->state & GDK_BUTTON1_MASK) == 0)
return TRUE;
- model->anchor_object = NULL;
+ closure->model->anchor_object = NULL;
return TRUE;
}
GdkEventMotion *event,
gpointer data)
{
- Model *model = data;
+ Closure *closure = data;
int x, y;
GdkModifierType state;
gdk_window_get_pointer (event->window, &x, &y, &state);
-
- model->anchor_position.x = x + 0.5;
- model->anchor_position.y = y + 0.5;
+
+ closure->model->anchor_position.x = x + 0.5;
+ closure->model->anchor_position.y = y + 0.5;
return TRUE;
}
static void
model_changed (GtkComboBox *combo, gpointer user_data)
{
- Model *model = user_data;
+ Closure *closure = user_data;
GtkTreeIter iter;
GtkTreeModel *tree_model;
ModelInitFunc init;
gtk_tree_model_get (tree_model, &iter, 0, &name, 1, &init, -1);
- model_fini (model);
- (*init) (model);
+ model_fini (closure->model);
+ (*init) (closure->model);
}
static GtkTreeModel *
} models[] = {
{ "Rope", model_init_rope },
{ "Snake", model_init_snake },
- { "Curtain", model_init_curtain }
+ { "Curtain", model_init_curtain },
+ { "Grid", model_init_grid },
+ { "Molecule", model_init_molecule },
+ { "Wobbly", model_init_wobbly }
};
GtkTreeIter iter;
}
static GtkWidget *
-create_model_combo (Model *model)
+create_model_combo (Closure *closure)
{
GtkWidget *hbox;
GtkWidget *combo, *label;
gtk_label_set_mnemonic_widget (GTK_LABEL (label), combo);
gtk_box_pack_start (GTK_BOX (hbox), combo, FALSE, FALSE, 0);
g_signal_connect (combo, "changed",
- G_CALLBACK (model_changed), model);
+ G_CALLBACK (model_changed), closure);
+
+ label = gtk_label_new ("Frames per second: 0");
+ gtk_box_pack_start (GTK_BOX (hbox), label, FALSE, FALSE, 0);
+
+ closure->fps_label = label;
return hbox;
}
-static GtkWidget *
-create_window (Model *model)
+static void
+create_window (Closure *closure)
{
GtkWidget *window;
GtkWidget *frame;
GtkWidget *model_combo;
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
- gtk_window_set_title (GTK_WINDOW (window), "Drawing Area");
+ gtk_window_set_title (GTK_WINDOW (window), "Akamaru");
g_signal_connect (window, "destroy",
G_CALLBACK (gtk_main_quit), &window);
da = gtk_drawing_area_new ();
/* set a minimum size */
- gtk_widget_set_size_request (da, 600, 500);
+ gtk_widget_set_size_request (da, 200, 200);
gtk_container_add (GTK_CONTAINER (frame), da);
/* Signals used to handle backing pixmap */
g_signal_connect (da, "expose_event",
- G_CALLBACK (expose_event), model);
+ G_CALLBACK (expose_event), closure);
/* Event signals */
g_signal_connect (da, "motion_notify_event",
- G_CALLBACK (motion_notify_event), model);
+ G_CALLBACK (motion_notify_event), closure);
g_signal_connect (da, "button_press_event",
- G_CALLBACK (button_press_event), model);
+ G_CALLBACK (button_press_event), closure);
g_signal_connect (da, "button_release_event",
- G_CALLBACK (button_release_event), model);
+ G_CALLBACK (button_release_event), closure);
/* Ask to receive events the drawing area doesn't normally
* subscribe to
| GDK_POINTER_MOTION_MASK
| GDK_POINTER_MOTION_HINT_MASK);
- model_combo = create_model_combo (model);
+ model_combo = create_model_combo (closure);
gtk_box_pack_start (GTK_BOX (vbox), model_combo, FALSE, FALSE, 0);
- return da;
+ closure->drawing_area = da;
}
-typedef struct _Closure Closure;
-struct _Closure {
- GtkWidget *drawing_area;
- Model *model;
- int i;
-};
-
static gint
timeout_callback (gpointer data)
{
Closure *closure = data;
- int i;
- for (i = 0; i < 3; i++)
- model_step (closure->model, 0.5);
+ model_step (closure->model, 1);
closure->i++;
if (closure->i == 1) {
gtk_widget_queue_draw (closure->drawing_area);
closure->i = 0;
+ closure->frame_count++;
+ }
+
+ if (closure->frame_count == 200) {
+ struct timeval end, elapsed;
+ double total;
+ char text[50];
+
+ closure->frame_count = 0;
+ gettimeofday (&end, NULL);
+ if (closure->start.tv_usec > end.tv_usec) {
+ end.tv_usec += 1000000;
+ end.tv_sec--;
+ }
+
+ elapsed.tv_usec = end.tv_usec - closure->start.tv_usec;
+ elapsed.tv_sec = end.tv_sec - closure->start.tv_sec;
+
+ total = elapsed.tv_sec + ((double) elapsed.tv_usec / 1e6);
+ if (total < 0) {
+ total = 0;
+ }
+ closure->start = end;
+ snprintf (text, sizeof text, "Frames per second: %.2f", 200 / total);
+ gtk_label_set_text (GTK_LABEL (closure->fps_label), text);
}
return TRUE;
gtk_init (&argc, &argv);
model_init_rope (&model);
- closure.drawing_area = create_window (&model);
+ create_window (&closure);
closure.i = 0;
gtk_widget_show_all (gtk_widget_get_toplevel (closure.drawing_area));
closure.model = &model;
- g_timeout_add (100, timeout_callback, &closure);
+ closure.frame_count = 0;
+ gettimeofday (&closure.start, NULL);
+ g_timeout_add (40, timeout_callback, &closure);
gtk_main ();
return 0;
projects / akamaru / blobdiff