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use fn over macro to silence warning
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See rust-lang/rust#31745
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@Ryan1729
Ryan1729 committed Feb 17, 2022
1 parent 5ddf18b commit 443e4fc
Showing 1 changed file with 86 additions and 85 deletions.
171 changes: 86 additions & 85 deletions game/src/game.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1834,95 +1834,94 @@ pub fn update(
// apply forces
state.board.player.velocity += player_impulse * dt;

/// returns Option<zo::XY>
macro_rules! bounce_vector_if_overlapping {
($player_triangles: expr) => {{
let mut bounce_vector = zo_xy!{};
let mut is_colliding = false;

'outer: for pw in $player_triangles.windows(2) {
// TODO Use a spatial partition to reduce the amount of mountain lines
// we need to test.
for mw in state.board.triangles.windows(2) {
is_colliding = lines_collide((pw[0], pw[1]), (mw[0], mw[1]));

if is_colliding {
// We want a vector that will separate the player from the
// collison. Since the player will enter a collision edge first,
// we point the vector towards the player's center.

// That's one point for the line that we derive the vector from,
// but we need another one. A natural other point for the vector
// is the center of the colliding line.
let line_center = zo_xy!{
(pw[0].x.0 + pw[1].x.0) / 2.,
(pw[0].y.0 + pw[1].y.0) / 2.,
};

// We have two potential normals here: we can either rotate by
// pi/2 radians, or -pi/2 radians. Recall that roating looks
// uses this transform for given angle:
// [
// cos(angle), -sin(angle), 0.,
// sin(angle), cos(angle), 0.,
// ]


// When the angle is pi/2, then the transform is the same as:
// [
// 0., -1., 0.,
// 1., 0., 0.,
// ]
// Inlining that gives us:
let line_normal_a = zo_xy!{-pw[0].y.0, pw[0].x.0};
// When the angle is -pi/2, then the transform is the same as:
// [
// 0., 1., 0.,
// -1., 0., 0.,
// ]
// Inlining that gives us:
let line_normal_b = zo_xy!{pw[0].y.0, -pw[0].x.0};

// Pick the one that points the closest to the player, so we
// bounce off of the mountain.
let line_normal = if zo::XY::distance_sq(
line_center + line_normal_a,
state.board.player.xy,
) < zo::XY::distance_sq(
line_center + line_normal_b,
state.board.player.xy,
) {
line_normal_a
} else {
line_normal_b
};

bounce_vector = 2.
* line_normal
* line_normal.dot(state.board.player.velocity);

// We want the bounce to be forceful enough that the collision
// stops, so we arbitrairaly scale it up to get that effect.
// TODO Derive a value here in a principled way?
bounce_vector *= 16.;

dbg!(stringify!($player_triangles), bounce_vector);

break 'outer;
}
fn bounce_vector_if_overlapping(
player: &Player,
mountain_triangles: &Triangles
) -> Option<zo::XY> {
let mut bounce_vector = zo_xy!{};
let mut is_colliding = false;

'outer: for pw in player.get_triangles().windows(2) {
// TODO Use a spatial partition to reduce the amount of mountain lines
// we need to test.
for mw in mountain_triangles.windows(2) {
is_colliding = lines_collide((pw[0], pw[1]), (mw[0], mw[1]));

if is_colliding {
// We want a vector that will separate the player from the
// collison. Since the player will enter a collision edge first,
// we point the vector towards the player's center.

// That's one point for the line that we derive the vector from,
// but we need another one. A natural other point for the vector
// is the center of the colliding line.
let line_center = zo_xy!{
(pw[0].x.0 + pw[1].x.0) / 2.,
(pw[0].y.0 + pw[1].y.0) / 2.,
};

// We have two potential normals here: we can either rotate by
// pi/2 radians, or -pi/2 radians. Recall that roating looks
// uses this transform for given angle:
// [
// cos(angle), -sin(angle), 0.,
// sin(angle), cos(angle), 0.,
// ]


// When the angle is pi/2, then the transform is the same as:
// [
// 0., -1., 0.,
// 1., 0., 0.,
// ]
// Inlining that gives us:
let line_normal_a = zo_xy!{-pw[0].y.0, pw[0].x.0};
// When the angle is -pi/2, then the transform is the same as:
// [
// 0., 1., 0.,
// -1., 0., 0.,
// ]
// Inlining that gives us:
let line_normal_b = zo_xy!{pw[0].y.0, -pw[0].x.0};

// Pick the one that points the closest to the player, so we
// bounce off of the mountain.
let line_normal = if zo::XY::distance_sq(
line_center + line_normal_a,
player.xy,
) < zo::XY::distance_sq(
line_center + line_normal_b,
player.xy,
) {
line_normal_a
} else {
line_normal_b
};

bounce_vector = 2.
* line_normal
* line_normal.dot(player.velocity);

// We want the bounce to be forceful enough that the collision
// stops, so we arbitrairaly scale it up to get that effect.
// TODO Derive a value here in a principled way?
bounce_vector *= 16.;

break 'outer;
}
}

is_colliding.then(|| bounce_vector)
}}
}

is_colliding.then(|| bounce_vector)
}

let mountain_colour;

if state.board.player.xy.y.0 < 0.
|| {
let already_overlapping = bounce_vector_if_overlapping!(
state.board.player.get_triangles()
let already_overlapping = bounce_vector_if_overlapping(
&state.board.player,
&state.board.triangles
).is_some();

already_overlapping
Expand All @@ -1940,8 +1939,9 @@ pub fn update(
new_player.angle += PI * dt;
}

if let Some(bounce_vector) = bounce_vector_if_overlapping!(
new_player.get_triangles()
if let Some(bounce_vector) = bounce_vector_if_overlapping(
&new_player,
&state.board.triangles
) {
// re-integrate including collision response
new_player = state.board.player.clone();
Expand All @@ -1954,8 +1954,9 @@ pub fn update(
new_player.angle += PI * dt;
}

if bounce_vector_if_overlapping!(
new_player.get_triangles()
if bounce_vector_if_overlapping(
&new_player,
&state.board.triangles
).is_some() {
mountain_colour = draw::Colour::Flag;

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