Fix interval overlap case for collision detection

If one interval were completely contained within another then the logic would
not correctly identify the overlap. Instead check the length of the intervals
and ensure the smaller interval of the two is compared against the larger one.
This commit is contained in:
Doyle Thai 2016-11-24 00:27:24 +11:00
parent 614fa53487
commit 6069ed8415
2 changed files with 51 additions and 31 deletions

View File

@ -389,6 +389,34 @@ b32 moveEntity(GameState *state, Entity *entity, i32 entityIndex, v2 ddP,
return willCollide; return willCollide;
} }
INTERNAL void addAsteroid(GameState *state, v2 windowSize)
{
Entity *asteroid = &state->entityList[state->entityIndex];
asteroid->id = state->entityIndex++;
i32 randValue = rand();
i32 randX = (randValue % (i32)windowSize.w);
i32 randY = (randValue % (i32)windowSize.h);
asteroid->pos = V2i(randX, randY);
asteroid->size = V2(75.0f, 75.0f);
asteroid->hitbox = asteroid->size;
asteroid->offset = V2(asteroid->size.w * -0.5f, 0);
asteroid->scale = 1;
asteroid->rotation = 45;
asteroid->type = entitytype_asteroid;
asteroid->direction = direction_null;
asteroid->renderMode = rendermode_polygon;
asteroid->numVertexPoints = 10;
asteroid->vertexPoints = createAsteroidVertexList(
&state->persistentArena, asteroid->numVertexPoints,
(i32)(asteroid->size.x * 0.5f));
asteroid->tex = NULL;
asteroid->collides = TRUE;
}
void asteroid_gameUpdateAndRender(GameState *state, Memory *memory, void asteroid_gameUpdateAndRender(GameState *state, Memory *memory,
v2 windowSize, f32 dt) v2 windowSize, f32 dt)
{ {
@ -406,34 +434,9 @@ void asteroid_gameUpdateAndRender(GameState *state, Memory *memory,
state->pixelsPerMeter = 70.0f; state->pixelsPerMeter = 70.0f;
{ // Init asteroid entities { // Init asteroid entities
i32 numAsteroids = 1; i32 numAsteroids = 15;
for (i32 i = 0; i < numAsteroids; i++) for (i32 i = 0; i < numAsteroids; i++)
{ addAsteroid(state, windowSize);
Entity *asteroid = &state->entityList[state->entityIndex];
asteroid->id = state->entityIndex++;
i32 randValue = rand();
i32 randX = (randValue % (i32)windowSize.w);
i32 randY = (randValue % (i32)windowSize.h);
asteroid->pos = V2i(100 + (i * 100), 500);
asteroid->size = V2(100.0f, 100.0f);
asteroid->hitbox = asteroid->size;
asteroid->offset = V2(asteroid->size.w * -0.5f, 0);
asteroid->scale = 1;
asteroid->rotation = 45;
asteroid->type = entitytype_asteroid;
asteroid->direction = direction_null;
asteroid->renderMode = rendermode_polygon;
asteroid->numVertexPoints = i + 10;
asteroid->vertexPoints = createAsteroidVertexList(
&state->persistentArena, asteroid->numVertexPoints,
(i32)(asteroid->size.x * 0.5f));
asteroid->tex = NULL;
asteroid->collides = TRUE;
}
} }
#if 1 #if 1
@ -503,6 +506,12 @@ void asteroid_gameUpdateAndRender(GameState *state, Memory *memory,
} }
} }
if (getKeyStatus(&state->input.keys[keycode_left_square_bracket],
readkeytype_repeat, 0.2f, dt))
{
addAsteroid(state, windowSize);
}
for (i32 i = 0; i < state->entityIndex; i++) for (i32 i = 0; i < state->entityIndex; i++)
{ {
Entity *entity = &state->entityList[i]; Entity *entity = &state->entityList[i];
@ -574,7 +583,7 @@ void asteroid_gameUpdateAndRender(GameState *state, Memory *memory,
} }
v2 ddP = {0}; v2 ddP = {0};
#if 0 #if 1
switch (entity->direction) switch (entity->direction)
{ {
case direction_north: case direction_north:
@ -642,8 +651,8 @@ void asteroid_gameUpdateAndRender(GameState *state, Memory *memory,
// NOTE(doyle): Make asteroids start and move at constant speed // NOTE(doyle): Make asteroids start and move at constant speed
ddPSpeedInMs = 1; ddPSpeedInMs = 1;
entity->dP = v2_scale(ddP, state->pixelsPerMeter * ddPSpeedInMs); entity->dP = v2_scale(ddP, state->pixelsPerMeter * ddPSpeedInMs);
#endif
entity->rotation += (60 * dt); entity->rotation += (60 * dt);
#endif
} }
b32 willCollide = moveEntity(state, entity, i, ddP, dt, ddPSpeedInMs); b32 willCollide = moveEntity(state, entity, i, ddP, dt, ddPSpeedInMs);
@ -661,7 +670,7 @@ void asteroid_gameUpdateAndRender(GameState *state, Memory *memory,
entityColor, flags); entityColor, flags);
} }
#if 0 #if 1
debug_drawUi(state, dt); debug_drawUi(state, dt);
debug_clearCounter(); debug_clearCounter();
#endif #endif

View File

@ -191,9 +191,20 @@ INTERNAL inline v2 v2_normalise(const v2 a)
return result; return result;
} }
INTERNAL inline b32 v2_intervalsOverlap(const v2 a, const v2 b) INTERNAL inline b32 v2_intervalsOverlap(v2 a, v2 b)
{ {
b32 result = FALSE; b32 result = FALSE;
f32 lenOfA = a.max - a.min;
f32 lenOfB = b.max - b.min;
if (lenOfA > lenOfB)
{
v2 tmp = a;
a = b;
b = tmp;
}
if ((a.min >= b.min && a.min <= b.max) || if ((a.min >= b.min && a.min <= b.max) ||
(a.max >= b.min && a.max <= b.max)) (a.max >= b.min && a.max <= b.max))
{ {