#include "sdr.h"
#include "mesh.h"
#include "meshgen.h"
+#include "goatkit/goatkit.h"
/* NOTES:
* - whistle hhgg music
- * - colliding particles merge
* - select objects and center camera on them
- * - tesselate only where necessary
+ * - we need to rely on actual collisions instead of grid occupancy
*/
struct Particle {
Vec2 pos;
Vec2 vel;
+ float vis_height;
+
Particle *next, *prev;
};
#define CONTRIB_THRES 0.005
#define CONTRIB_RANGE(m) sqrt((m) / CONTRIB_THRES)
+/* gravitational strength */
+#define GRAV_STR 16.0f
+
+#define INIT_MASS_BUDGET 600.0f
+#define EM_MASS_DEFAULT 100.0f
+
+static int pos_to_grid_x_noclamp(float x);
+static int pos_to_grid_y_noclamp(float y);
static int pos_to_grid(float x, float y);
static Vec2 grid_to_pos(int gx, int gy);
static void calc_contrib_bounds(const Vec2 &pos, float mass, Rect *rect);
static void add_influence(const Vec2 &pos, float mass, float radius, const Rect &cbox);
+static Vec2 calc_field_grad(int gidx);
+
static void destroy_quadmesh(QuadMesh *m);
static void draw_quadmesh(const QuadMesh *m, unsigned int prim = GL_QUADS);
static void gen_quad_plane(QuadMesh *mesh, float width, float height, int usub, int vsub);
static void spawn_particle(const Vec2 &pos, const Vec2 &vel, float mass);
-static void add_particle(Particle *p, int grid_idx);
-static void remove_particle(Particle *p, int grid_idx);
+static void add_particle(Particle *p);
+static void remove_particle(Particle *p);
static Particle *alloc_particle();
void free_particle(Particle *p);
+static bool pause;
+
static float grid[GRID_SIZE * GRID_SIZE];
static Particle *grid_part[GRID_SIZE * GRID_SIZE];
static Texture *grid_tex;
-#define NUM_PARTICLE_LISTS 16
-static Particle *plist[NUM_PARTICLE_LISTS];
-#define GRID_IDX_PLIST(idx) ((idx) * NUM_PARTICLE_LISTS / (GRID_SIZE * GRID_SIZE))
+static Particle *plist;
static std::vector<Emitter*> emitters;
static Texture *gvis_tex; // texture tile for visualizing a grid
static unsigned int field_sdr;
-static int tess_level = 32;
+static int tess_level = 64;
static float field_scale = 16.0f;
static QuadMesh field_mesh;
static Mesh *pmesh;
static unsigned int particle_sdr;
+static Vec2 cam_pos;
static float cam_theta;
static float cam_dist = 100.0f;
-static Vec2 *targ_pos;
+static Vec2 *targ_pos = &cam_pos;
static Mat4 view_matrix, proj_matrix;
+static bool wireframe;
+static int mouse_x, mouse_y;
+
// emitter placement data (filled by event handlers, completed in update)
static bool emit_place_pending;
static Vec2 emit_place_pos;
+static bool placing_emitter;
+
+static float mass_left;
+
+// UI
+static void ui_handler(goatkit::Widget *w, const goatkit::Event &ev, void *cls);
+static int ui_virt_width = 800;
+static int ui_virt_height = 600;
+static goatkit::Screen *ui;
+static goatkit::Button *bn_emitter;
+static goatkit::Slider *slider_mass;
+static bool mouse_over_ui;
+
bool GameScreen::init()
{
return false;
}
- // XXX DBG
- emit_place_pos = Vec2(0, 0);
- emit_place_pending = true;
+ mass_left = INIT_MASS_BUDGET;
+
+ ui = new goatkit::Screen;
+ ui->hide();
+
+ bn_emitter = new goatkit::Button;
+ bn_emitter->set_position(5, 5);
+ bn_emitter->set_size(250, 30);
+ bn_emitter->set_text("new white hole");
+ bn_emitter->set_callback(goatkit::EV_CLICK, ui_handler);
+ ui->add_widget(bn_emitter);
+
+ slider_mass = new goatkit::Slider;
+ slider_mass->set_position(300, 5);
+ slider_mass->set_size(400, 30);
+ slider_mass->set_continuous_change(false);
+ slider_mass->set_range(0, mass_left);
+ slider_mass->set_value(EM_MASS_DEFAULT);
+ slider_mass->set_callback(goatkit::EV_CHANGE, ui_handler);
+ ui->add_widget(slider_mass);
+
+ ui->set_visibility_transition(300);
assert(glGetError() == GL_NO_ERROR);
return true;
delete grid_tex;
destroy_quadmesh(&field_mesh);
delete pmesh;
+
+ delete bn_emitter;
+}
+
+void GameScreen::start()
+{
+ ui->show();
+ slider_mass->hide();
+}
+
+void GameScreen::stop()
+{
}
static void simstep()
{
+ if(pause) return;
+
+ // distribute forces
+ Particle *p = plist;
+ while(p) {
+ int num_emitters = emitters.size();
+ for(int i=0; i<num_emitters; i++) {
+ Emitter *em = emitters[i];
+ Vec2 dir = p->pos - em->pos;
+ p->vel += dir * em->mass * GRAV_STR * 0.01 / dot(dir, dir) * SIM_DT;
+ }
+
+ Particle *q = plist;
+ while(q) {
+ if(p != q) {
+ Vec2 dir = q->pos - p->pos;
+ float accel = GRAV_STR * q->mass / dot(dir, dir);
+ p->vel += dir * accel * SIM_DT;
+ }
+ q = q->next;
+ }
+ p = p->next;
+ }
+
+ // move existing particles
+ p = plist;
+ while(p) {
+ // calculate the field gradient at the particle position
+ int gidx = pos_to_grid(p->pos.x, p->pos.y);
+ //Vec2 grad = calc_field_grad(gidx) * GRAV_STR;
+
+ //p->vel += grad * SIM_DT;
+ p->pos += p->vel * SIM_DT;
+
+ // if it moved outside of the simulation field, remove it
+ int gx = pos_to_grid_x_noclamp(p->pos.x);
+ int gy = pos_to_grid_y_noclamp(p->pos.y);
+ if(gx < 0 || gx >= GRID_SIZE || gy < 0 || gy >= GRID_SIZE) {
+ Particle *next = p->next;
+ grid_part[gidx] = 0;
+ remove_particle(p);
+ free_particle(p);
+ p = next;
+ continue;
+ }
+
+ // find the grid cell it's moving to
+ int gidx_next = pos_to_grid(p->pos.x, p->pos.y);
+ p->vis_height = 0.0f;//-grid[gidx_next] * field_scale;
+
+ if(gidx_next == gidx) {
+ p = p->next;
+ continue;
+ }
+
+ Particle *destp = grid_part[gidx_next];
+ if(destp) {
+ assert(destp != p);
+ // another particle at the destination, merge them
+ destp->vel += p->vel;
+ destp->mass += p->mass;
+ destp->radius = MASS_TO_RADIUS(destp->mass);
+
+ // ... and remove it
+ grid_part[gidx] = 0;
+ Particle *next = p->next;
+ remove_particle(p);
+ free_particle(p);
+ p = next;
+ } else {
+ // destination is empty, go there
+ if(gidx != gidx_next) {
+ grid_part[gidx] = 0;
+ grid_part[gidx_next] = p;
+ }
+
+ p = p->next;
+ }
+ }
+
+ // TODO destroy particles which left the simulation field
+
// spawn particles
int num_emitters = emitters.size();
for(int i=0; i<num_emitters; i++) {
}
// calculate gravitational field - assume field within radius constant: m / r^2
-
// first clear the field, and then add contributions
memset(grid, 0, sizeof grid);
}
// contribution of particles
- for(int i=0; i<NUM_PARTICLE_LISTS; i++) {
- Particle *p = plist[i];
- while(p) {
- Rect cbox;
- calc_contrib_bounds(p->pos, p->mass, &cbox);
- add_influence(p->pos, p->mass, p->radius, cbox);
- p = p->next;
- }
+ p = plist;
+ while(p) {
+ Rect cbox;
+ calc_contrib_bounds(p->pos, p->mass, &cbox);
+ add_influence(p->pos, p->mass, p->radius, cbox);
+ p = p->next;
}
// update texture
static void update()
{
+ if(placing_emitter) {
+ float x = (float)mouse_x / (float)win_width;
+ float y = 1.0f - (float)mouse_y / (float)win_height;
+ Ray pick_ray = mouse_pick_ray(x, y, view_matrix, proj_matrix);
+
+ float ndotdir = pick_ray.dir.y;
+ if(fabs(ndotdir) > 1e-6f) {
+ float ndotpdir = -pick_ray.origin.y;
+ float t = ndotpdir / ndotdir;
+
+ x = pick_ray.origin.x + pick_ray.dir.x * t;
+ y = pick_ray.origin.z + pick_ray.dir.z * t;
+
+ if(x >= -FIELD_SIZE / 2 && x < FIELD_SIZE / 2 &&
+ y >= -FIELD_SIZE / 2 && y < FIELD_SIZE / 2) {
+ emit_place_pos = Vec2(x, y);
+ }
+ }
+ }
+
if(emit_place_pending) {
emit_place_pending = false;
Emitter *em = new Emitter;
em->pos = emit_place_pos;
- em->mass = 100;
- em->rate = 1;
- em->chunk = 0.05 * em->mass;
+ em->mass = slider_mass->get_value();
+ em->rate = 10;
+ em->chunk = 0.001 * em->mass;
em->angle = -1;
em->spread = 0;
em->spawn_pending = 0;
emitters.push_back(em);
+ mass_left -= em->mass;
+ if(mass_left < 0.0f) mass_left = 0.0f;
+
Rect cbox;
calc_contrib_bounds(em->pos, em->mass, &cbox);
printf("bounds: %d,%d %dx%d\n", cbox.x, cbox.y, cbox.width, cbox.height);
glMatrixMode(GL_MODELVIEW);
glLoadMatrixf(view_matrix[0]);
- glPushAttrib(GL_ENABLE_BIT);
- glDisable(GL_CULL_FACE);
-
// draw gravitational field
- glEnable(GL_TEXTURE_2D);
+ if(wireframe) {
+ glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+
+ float amb[] = {0.5, 0.5, 0.5, 1.0};
+ glLightModelfv(GL_LIGHT_MODEL_AMBIENT, amb);
+ } else {
+ float amb[] = {0.01, 0.01, 0.01, 1.0};
+ glLightModelfv(GL_LIGHT_MODEL_AMBIENT, amb);
+ }
+
bind_texture(gvis_tex, 0);
bind_texture(grid_tex, 1);
glPatchParameteri(GL_PATCH_VERTICES, 4);
draw_quadmesh(&field_mesh, GL_PATCHES);
+ if(wireframe) {
+ glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+ }
+
// draw particles
glUseProgram(particle_sdr);
- for(int i=0; i<NUM_PARTICLE_LISTS; i++) {
- Particle *p = plist[i];
- while(p) {
- int gidx = pos_to_grid(p->pos.x, p->pos.y);
+ Particle *p = plist;
+ while(p) {
+ int gidx = pos_to_grid(p->pos.x, p->pos.y);
- glPushMatrix();
- glTranslatef(p->pos.x, -grid[gidx] * field_scale, p->pos.y);
- glScalef(p->radius, p->radius, p->radius);
+ glPushMatrix();
+ glTranslatef(p->pos.x, p->vis_height, p->pos.y);
+ glScalef(p->radius, p->radius, p->radius);
- pmesh->draw();
+ pmesh->draw();
- glPopMatrix();
- p = p->next;
- }
+ glPopMatrix();
+ p = p->next;
}
glUseProgram(0);
- glPopAttrib();
+ // draw emitter placement marker if we are in placement mode
+ if(placing_emitter && !mouse_over_ui) {
+ glPushMatrix();
+ glTranslatef(emit_place_pos.x, 0, emit_place_pos.y);
+
+ glBegin(GL_LINES);
+ glColor3f(0, 1, 0);
+ glVertex3f(0, -1000, 0);
+ glVertex3f(0, 1000, 0);
+ glEnd();
+
+ float s = MASS_TO_RADIUS(slider_mass->get_value());
+ if(s < 0.1) s = 0.1;
+ glScalef(s, s, s);
+
+ glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+ pmesh->draw();
+ glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+
+ glPopMatrix();
+ }
+
+ // draw the UI
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glOrtho(0, ui_virt_width, ui_virt_height, 0, -1, 1);
+
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+
+ ui->draw();
+
assert(glGetError() == GL_NO_ERROR);
}
void GameScreen::reshape(int x, int y)
{
+ ui_virt_width = x;
+ ui_virt_height = y;
+ ui->set_size(ui_virt_width, ui_virt_height);
}
set_uniform_float(field_sdr, "field_scale", field_scale);
break;
+ case 'w':
+ wireframe = !wireframe;
+ break;
+
+ case ' ':
+ pause = !pause;
+ break;
+
default:
break;
}
}
}
-static int prev_x, prev_y;
+#define UI_HEIGHT 50
void GameScreen::mbutton(int bn, bool pressed, int x, int y)
{
- prev_x = x;
- prev_y = y;
+ mouse_x = x;
+ mouse_y = y;
+
+ mouse_over_ui = y < UI_HEIGHT;
+
+ ui->sysev_mouse_button(bn, pressed, x * ui_virt_width / win_width,
+ y * ui_virt_height / win_height);
+
+ if(placing_emitter && bn == 0 && pressed && !mouse_over_ui) {
+ emit_place_pending = true;
+ placing_emitter = false;
+ slider_mass->hide();
+ }
}
void GameScreen::mmotion(int x, int y)
{
- int dx = x - prev_x;
- int dy = y - prev_y;
- prev_x = x;
- prev_y = y;
+ int dx = x - mouse_x;
+ int dy = y - mouse_y;
+ mouse_x = x;
+ mouse_y = y;
+
+ mouse_over_ui = y < UI_HEIGHT;
+
+ ui->sysev_mouse_motion(x * ui_virt_width / win_width, y * ui_virt_height / win_height);
+ if(ui->get_mouse_grab()) {
+ return;
+ }
+
+ if(game_bnstate(0)) {
+ float pan_speed = pow(cam_dist, 1.5) * 0.00035; // magic
+ Vec2 dir = rotate(Vec2(dx, dy) * pan_speed, deg_to_rad(cam_theta));
+ cam_pos.x -= dir.x;
+ cam_pos.y -= dir.y;
+ }
if(game_bnstate(2)) {
cam_theta += dx * 0.5;
if(cam_dist > MAX_CAM_DIST) cam_dist = MAX_CAM_DIST;
}
+static void ui_handler(goatkit::Widget *w, const goatkit::Event &ev, void *cls)
+{
+ if(w == bn_emitter) {
+ if(placing_emitter) {
+ placing_emitter = false;
+ slider_mass->hide();
+ } else {
+ if(mass_left > 0.0f) {
+ placing_emitter = true;
+ slider_mass->set_range(0, mass_left);
+ slider_mass->set_value(mass_left >= EM_MASS_DEFAULT ? EM_MASS_DEFAULT : mass_left);
+ slider_mass->show();
+ }
+ }
+ return;
+ }
+
+ if(w == slider_mass) {
+ printf("foo: %f\n", slider_mass->get_value());
+ }
+}
+
+static int pos_to_grid_x_noclamp(float x)
+{
+ return ((x / (float)FIELD_SIZE) + 0.5f) * (float)GRID_SIZE;
+}
+
+static int pos_to_grid_y_noclamp(float y)
+{
+ return ((y / (float)FIELD_SIZE) + 0.5f) * (float)GRID_SIZE;
+}
static int pos_to_grid(float x, float y)
{
- int gx = ((x / (float)FIELD_SIZE) + 0.5f) * (float)GRID_SIZE;
- int gy = ((y / (float)FIELD_SIZE) + 0.5f) * (float)GRID_SIZE;
+ int gx = pos_to_grid_x_noclamp(x);
+ int gy = pos_to_grid_y_noclamp(y);
if(gx < 0) gx = 0;
if(gx >= GRID_SIZE) gx = GRID_SIZE - 1;
}
}
+static Vec2 calc_field_grad(int gidx)
+{
+ int gx = GRID_X(gidx);
+ int gy = GRID_Y(gidx);
+
+ int nidx = ((gx + 1 >= GRID_SIZE ? gx : gx + 1) << GRID_BITS) | gy;
+ int pidx = ((gx > 0 ? gx - 1 : gx) << GRID_BITS) | gy;
+ float dfdx = grid[nidx] - grid[pidx];
+
+ nidx = (gx << GRID_BITS) | (gy + 1 >= GRID_SIZE ? gy : gy + 1);
+ pidx = (gx << GRID_BITS) | (gy > 0 ? gy - 1 : gy);
+ float dfdy = grid[nidx] - grid[pidx];
+
+ return Vec2(dfdx, dfdy);
+}
+
+
+// ---- quad mesh operations ----
static void destroy_quadmesh(QuadMesh *m)
{
int idx = i * vverts + j;
*iptr++ = idx;
- *iptr++ = idx + vverts;
- *iptr++ = idx + vverts + 1;
*iptr++ = idx + 1;
+ *iptr++ = idx + vverts + 1;
+ *iptr++ = idx + vverts;
}
v += dv;
p->radius = MASS_TO_RADIUS(mass);
grid_part[gidx] = p;
- add_particle(p, gidx);
+ add_particle(p);
}
}
-static void add_particle(Particle *p, int grid_idx)
+static void add_particle(Particle *p)
{
- int listidx = GRID_IDX_PLIST(grid_idx);
- p->next = plist[listidx];
+ if(plist) plist->prev = p;
+
+ p->next = plist;
p->prev = 0;
- plist[listidx] = p;
+ plist = p;
}
-static void remove_particle(Particle *p, int grid_idx)
+static void remove_particle(Particle *p)
{
- Particle *prev = p->prev;
- Particle *next = p->next;
-
- p->prev = p->next = 0;
- if(next) next->prev = prev;
+ assert(plist->prev == 0);
- if(prev) {
- prev->next = next;
- } else {
- int listidx = GRID_IDX_PLIST(grid_idx);
- plist[listidx] = next;
+ if(plist == p) {
+ assert(p->prev == 0);
+ plist = p->next;
}
+ if(p->prev) {
+ p->prev->next = p->next;
+ }
+ if(p->next) {
+ p->next->prev = p->prev;
+ }
+ p->prev = p->next = 0;
}
// particle allocator
projects / ld42_outofspace / blobdiff