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Add some juice to platformer example

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This commit is contained in:
Nikita Lisitsa 2023-05-13 10:36:39 +03:00
parent 1ef17e8918
commit 30ed7a781e
1 changed files with 131 additions and 10 deletions
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141
examples/platformer.cpp
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@ -6,6 +6,8 @@
#include <psemek/geom/camera.hpp>
#include <psemek/geom/constants.hpp>
#include <psemek/geom/intersection.hpp>
#include <psemek/random/generator.hpp>
#include <psemek/random/uniform.hpp>
#include <psemek/util/clock.hpp>
#include <psemek/util/to_string.hpp>
@ -22,12 +24,26 @@ struct player
geom::point<float, 2> position;
geom::vector<float, 2> velocity;
geom::point<float, 2> ghost_position;
geom::vector<float, 2> ghost_velocity;
bool grounded = false;
geom::box<float, 2> bbox() const
{
return geom::expand(geom::box<float, 2>::singleton(position), size);
}
};
struct particle
{
geom::point<float, 2> position;
geom::vector<float, 2> velocity;
float size;
float lifetime;
gfx::color_rgba color;
};
struct platformer_app : app::app
{
platformer_app()
@ -44,6 +60,8 @@ struct platformer_app : app::app
player_.size = {0.25f, 0.5f};
player_.position = {0.f, 5.f};
player_.velocity = {0.f, 0.f};
player_.ghost_position = player_.position;
player_.ghost_velocity = {0.f, 0.f};
}
void update() override
@ -51,14 +69,17 @@ struct platformer_app : app::app
float const dt = frame_clock_.restart().count();
float const gravity = -50.f;
float const acceleration = 50.f;
float const friction = 10.f;
float const acceleration = 200.f;
float const friction = 25.f;
float const jump_speed = 15.f;
if (is_key_down(SDLK_a))
player_.velocity[0] -= acceleration * dt;
if (is_key_down(SDLK_d))
player_.velocity[0] += acceleration * dt;
geom::vector const ghost_spring_force{200.f, 500.f};
geom::vector const ghost_spring_damping{10.f, 20.f};
float const particle_grow_speed = 0.1f;
float const move_particle_spawn_period = 1.f / 32.f;
int const jump_particle_count = 16;
int const land_particle_count = 32;
player_.velocity[0] *= std::exp(- friction * dt);
@ -66,7 +87,18 @@ struct platformer_app : app::app
player_.position += player_.velocity * dt;
bool grounded = false;
{
auto v = (player_.position - player_.ghost_position);
player_.ghost_velocity += geom::pointwise_mult(v, ghost_spring_force) * dt;
player_.ghost_velocity[0] *= std::exp(- ghost_spring_damping[0] * dt);
player_.ghost_velocity[1] *= std::exp(- ghost_spring_damping[1] * dt);
}
player_.ghost_position += player_.ghost_velocity * dt;
bool was_grounded = player_.grounded;
auto velocity_before_collision = player_.velocity;
player_.grounded = false;
for (auto const & platform : map_.platforms)
{
@ -88,7 +120,7 @@ struct platformer_app : app::app
if (intersection[1].center() < player_.position[1])
{
player_.position[1] += intersection[1].length();
grounded = true;
player_.grounded = true;
}
else
player_.position[1] -= intersection[1].length();
@ -97,8 +129,77 @@ struct platformer_app : app::app
}
}
if (grounded && is_key_down(SDLK_w))
if (is_key_down(SDLK_a))
player_.velocity[0] -= acceleration * dt;
if (is_key_down(SDLK_d))
player_.velocity[0] += acceleration * dt;
if (player_.grounded && (is_key_down(SDLK_a) ^ is_key_down(SDLK_d)))
{
move_particle_spawn_timer_ += dt;
if (move_particle_spawn_timer_ > move_particle_spawn_period)
{
move_particle_spawn_timer_ -= move_particle_spawn_period;
float s = is_key_down(SDLK_a) ? 1.f : -1.f;
auto position = player_.position + geom::vector{s * player_.size[0], -player_.size[1]};
auto velocity = geom::direction(random::uniform(rng_, geom::rad(60.f), geom::rad(120.f)));
auto size = random::uniform(rng_, 0.05f, 0.15f);
auto lifetime = random::uniform(rng_, 0.25f, 0.5f);
int c = random::uniform(rng_, 63, 191);
gfx::color_rgba color{c, 0, c, 255};
particles_.push_back({position, velocity, size, lifetime, color});
}
}
if (player_.grounded && is_key_down(SDLK_w))
{
player_.velocity[1] += jump_speed;
for (int i = 0; i < jump_particle_count; ++i)
{
float s = random::uniform(rng_, -1.f, 1.f);
auto position = player_.position + geom::vector{s * player_.size[0], -player_.size[1]};
auto velocity = (random::uniform<bool>(rng_) ? 1.f : -1.f) * geom::direction(random::uniform(rng_, geom::rad(-30.f), geom::rad(30.f))) * 3.f;
auto size = random::uniform(rng_, 0.05f, 0.15f);
auto lifetime = random::uniform(rng_, 0.25f, 0.5f);
int c = random::uniform(rng_, 63, 191);
gfx::color_rgba color{c, 0, c, 255};
particles_.push_back({position, velocity, size, lifetime, color});
}
}
if (!was_grounded && player_.grounded)
{
for (int i = 0; i < land_particle_count; ++i)
{
float s = random::uniform(rng_, -1.f, 1.f);
auto position = player_.position + geom::vector{s * player_.size[0], -player_.size[1]};
auto velocity = geom::direction(random::uniform(rng_, geom::rad(0.f), geom::rad(180.f))) * (-velocity_before_collision[1]) * 0.2f;
auto size = random::uniform(rng_, 0.05f, 0.15f);
auto lifetime = random::uniform(rng_, 0.25f, 0.5f);
int c = random::uniform(rng_, 63, 191);
gfx::color_rgba color{c, 0, c, 255};
particles_.push_back({position, velocity, size, lifetime, color});
}
}
std::vector<particle> alive_particles;
for (auto & p : particles_)
{
p.lifetime -= dt;
if (p.lifetime <= 0.f) continue;
p.position += p.velocity * dt;
p.size += particle_grow_speed * dt;
alive_particles.push_back(p);
}
particles_ = std::move(alive_particles);
}
void present() override
@ -109,7 +210,23 @@ struct platformer_app : app::app
for (auto const & box : map_.platforms)
painter_.rect(box, {0, 0, 0, 255});
painter_.rect(player_.bbox(), {255, 0, 0, 255});
{
geom::point bottom = player_.position - geom::vector{0.f, player_.size[1]};
geom::point top = player_.ghost_position + geom::vector{0.f, player_.size[1]};
auto d = geom::vector{player_.size[0], 0.f};
gfx::color_rgba color{255, 0, 0, 255};
painter_.triangle(bottom - d, bottom + d, top - d, color);
painter_.triangle(bottom + d, top - d, top + d, color);
}
for (auto const & p : particles_)
{
auto colorf = gfx::to_colorf(p.color);
colorf[3] *= 1.f - std::exp(- 2.f * p.lifetime);
painter_.circle(p.position, p.size, gfx::to_coloru8(colorf));
}
float const aspect_ratio = width() * 1.f / height();
float const view_size = 5.f;
@ -121,6 +238,10 @@ struct platformer_app : app::app
private:
map map_;
player player_;
std::vector<particle> particles_;
float move_particle_spawn_timer_ = 0.f;
random::generator rng_;
util::clock<> frame_clock_;
gfx::painter painter_;