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/apps/demos/scenery: something...

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veclavtalica
2025-03-02 23:19:27 +03:00
parent 4e5ff9433c
commit ed8e826b94
2 changed files with 79 additions and 41 deletions
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118
apps/demos/scenery/scenes/ingame.c
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@@ -53,17 +53,18 @@ static float heightmap[TERRAIN_DISTANCE][TERRAIN_DISTANCE];
/* else if length(v(o) + (F(o)/m)*t) <= (f(k)*x(n)*t), v(o) = 0 */ /* else if length(v(o) + (F(o)/m)*t) <= (f(k)*x(n)*t), v(o) = 0 */
/* else, F = -unit(v(o)*f(k)*x(n)) */ /* else, F = -unit(v(o)*f(k)*x(n)) */
#define VEHICLE_MASS 200.0f #define VEHICLE_MASS 150.0f
#define VEHICLE_LENGTH 3.0f #define VEHICLE_LENGTH 3.0f
#define VEHICLE_WIDTH 1.7f #define VEHICLE_WIDTH 1.7f
#define VEHICLE_HEIGHT 1.3f #define VEHICLE_HEIGHT 1.3f
/* spring constant */ /* spring constant */
#define VEHICLE_SPRING_K 50000.0f #define VEHICLE_SPRING_K 80000.0f
/* damping constant */ /* damping constant */
#define VEHICLE_SPRING_C 200.0f #define VEHICLE_SPRING_C 500.0f
#define VEHICLE_FRICTION_S 50000.0f #define VEHICLE_FRICTION_S 1000.0f
#define VEHICLE_FRICTION_K 700.0f #define VEHICLE_FRICTION_K 100.0f
/* TODO: shock springs, that are more loose, which are used to simulate the wheels */
/* initial, ideal corner positions */ /* initial, ideal corner positions */
static const Vec3 vbpi[8] = { static const Vec3 vbpi[8] = {
[0] = { 0, 0, 0 }, [0] = { 0, 0, 0 },
@@ -141,48 +142,83 @@ static void process_vehicle(SceneIngame *scn) {
Vec3 const v = vbv[i]; Vec3 const v = vbv[i];
float const h = height_at(scn, (Vec2){ p.x, p.z }); float const h = height_at(scn, (Vec2){ p.x, p.z });
if (h >= p.y) { if (h >= p.y) {
/* displacement force */ /* wheel processing */
if (i == 0 || i == 3) {
if (scn->camera_mode == 2 && input_action_pressed("player_forward")) {
Vec3 const dir = i == 0 ? vec3_sub(vbp[0], vbp[1]) : vec3_sub(vbp[3], vbp[2]);
Facc[i] = vec3_add(Facc[i], vec3_scale(vec3_norm(dir), 18000));
}
}
/* normal force, for displacement */
Vec3 const n = normal_at(scn, (Vec2){ p.x, p.z }); Vec3 const n = normal_at(scn, (Vec2){ p.x, p.z });
float const xn = (h - p.y) * n.y; float const xn = (h - p.y) * n.y;
float const vn = vec3_dot(v, n); float const vn = vec3_dot(v, n);
Vec3 const Fd = vec3_scale(n, -VEHICLE_SPRING_K * xn - VEHICLE_SPRING_C * vn); Vec3 const Fn = vec3_scale(n, -VEHICLE_SPRING_K * xn - VEHICLE_SPRING_C * vn);
Facc[i] = vec3_sub(Facc[i], Fd);
/* friction force, perpendicular to displacement */ /* friction force, perpendicular to normal force */
/* portions aligned to surface normal */ Vec3 const vo = vec3_sub(v, vec3_scale(n, vn));
Vec3 const vov = vec3_sub(v, vec3_scale(n, vn)); float const vol = vec3_length(vo);
draw_line_3d(vbp[i], vec3_add(vbp[i], vec3_scale(vov, 3)), 1, (Color){255, 0, 0, 255}); Vec3 Fo = vec3_sub(Facc[i], vec3_scale(n, vec3_dot(Facc[i], n)));
float const vo = vec3_length(vov); /* portion of total force along the surface */
Vec3 const Fov = vec3_sub(Facc[i], vec3_scale(n, vec3_dot(Facc[i], n))); float const Fol = vec3_length(Fo);
float const Fo = vec3_length(Fov); float const fkxn = VEHICLE_FRICTION_K * xn * 50;
float const fkxn = VEHICLE_FRICTION_K * xn; /* at rest, might want to start moving */
if (fabsf(0.0f - vo) <= 0.001f) { if (fabsf(0.0f - vol) <= 0.0001f) {
/* cannot overcome static friction, zero force along the surface */ /* cannot overcome static friction, force along the surface is zeroed */
if (Fo <= VEHICLE_FRICTION_S * xn) { if (Fol <= VEHICLE_FRICTION_S * xn) Fo = (Vec3){0};
// Facc[i] = vec3_sub(Facc[i], Fov); /* resist the force by friction, while starting to move */
Facc[i] = (Vec3){0}; else Fo = vec3_sub(Fo, vec3_scale(vec3_norm(Fo), fkxn));
} /* not at rest, stop accelerating along the surface */
/* apply kinematic friction */ } else if (vol + (Fol / VEHICLE_MASS) * ctx.frame_duration <= fkxn * ctx.frame_duration) {
else { log_info("test 1");
Facc[i] = vec3_sub(Fov, vec3_scale(vec3_norm(Fov), fkxn)); // vbv[i] = vec3_sub(vbp[i], vo);
}
/* velocity with gain along the surface will not overcome */
} else if (vec3_length(vec3_add(vov, vec3_scale(vec3_scale(Fov, (1.0f / VEHICLE_MASS)), ctx.frame_duration))) <= fkxn * ctx.frame_duration) {
// vbv[i] = vec3_sub(vbv[i], vov);
vbv[i] = (Vec3){0}; vbv[i] = (Vec3){0};
/* just apply friction */
} else { } else {
Facc[i] = vec3_sub(Facc[i], vec3_scale(vec3_norm(vov), fkxn)); log_info("test 2, depth: %f", xn);
Fo = vec3_add(Fo, vec3_scale(vec3_norm(vo), -fkxn * 100));
} }
/* total force, after ground interaction */
Vec3 const Ft = vec3_add(vec3_scale(Fn, -1), Fo);
Vec3 vd = vec3_scale(vec3_scale(Ft, (1.0f / VEHICLE_MASS)), ctx.frame_duration);
vbv[i] = vec3_add(vbv[i], vd);
vbp[i] = vec3_add(vbp[i], vec3_scale(vbv[i], ctx.frame_duration));
} else {
/* in air */
Vec3 vd = vec3_scale(vec3_scale(Facc[i], (1.0f / VEHICLE_MASS)), ctx.frame_duration);
vbv[i] = vec3_add(vbv[i], vd);
vbp[i] = vec3_add(vbp[i], vec3_scale(vbv[i], ctx.frame_duration));
} }
} }
}
/* integrate forces and velocity */
for (size_t i = 0; i < 8; ++i) { static void process_vehicle_mode(State *state) {
Vec3 vd = vec3_scale(vec3_scale(Facc[i], (1.0f / VEHICLE_MASS)), ctx.frame_duration); SceneIngame *scn = (SceneIngame *)state->scene;
if (vec3_length(vd) <= 0.02f) vd = (Vec3){0}; /* TODO: dirty hack... */
vbv[i] = vec3_add(vbv[i], vd); Vec3 const top_center = vec3_sub(vbp[4], vec3_scale(vec3_sub(vbp[4], vbp[6]), 1.0f / 2.0f));
vbp[i] = vec3_add(vbp[i], vec3_scale(vbv[i], ctx.frame_duration)); // Vec3 const front_center = vec3_add(vbp[4], vec3_scale(vec3_sub(vbp[4], vbp[7]), 1.0f / 2.0f));
} // Vec3 const facing_direction = vec3_sub(top_center, front_center);
float yawc, yaws, pitchc, pitchs;
sincosf(scn->yaw + (float)M_PI_2, &yaws, &yawc);
sincosf(scn->pitch, &pitchs, &pitchc);
Vec3 const looking_direction = vec3_norm(((Vec3){
yawc * pitchc,
pitchs,
yaws * pitchc,
}));
Vec3 const orbit = vec3_sub(top_center, vec3_scale(looking_direction, 10));
draw_camera(orbit, looking_direction, (Vec3){0,1,0}, (float)M_PI_2 * 0.8f, 1, TERRAIN_RADIUS * sqrtf(3));
scn->looking_direction = looking_direction;
scn->pos = top_center;
} }
@@ -435,12 +471,14 @@ static void ingame_tick(State *state) {
} }
if (input_action_just_pressed("toggle_camera_mode")) if (input_action_just_pressed("toggle_camera_mode"))
scn->flying_camera = !scn->flying_camera; scn->camera_mode = scn->camera_mode == 2 ? 0 : scn->camera_mode + 1;
if (scn->flying_camera) { if (scn->camera_mode == 1) {
process_fly_mode(state); process_fly_mode(state);
} else { } else if (scn->camera_mode == 0) {
process_ground_mode(state); process_ground_mode(state);
} else if (scn->camera_mode) {
process_vehicle_mode(state);
} }
/* toggle mouse capture with end key */ /* toggle mouse capture with end key */

2
apps/demos/scenery/scenes/ingame.h
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@@ -21,7 +21,7 @@ typedef struct SceneIngame {
float roll; float roll;
bool mouse_captured; bool mouse_captured;
bool flying_camera; int camera_mode;
} SceneIngame; } SceneIngame;