Function updatePosWithParticle

core/2d/ParticleSystemQuad.cpp:265–309

}

inline void updatePosWithParticle(V3F_C4B_T2F_Quad* quad,
                                  const Vec2& newPosition,
                                  float size,
                                  float scaleInSize,
                                  float rotation,
                                  float staticRotation)
{
    // vertices
    float size_2 = size / 2;
    float x1     = -size_2 * scaleInSize;
    float y1     = -size_2 * scaleInSize;

    float x2 = size_2 * scaleInSize;
    float y2 = size_2 * scaleInSize;
    float x  = newPosition.x;
    float y  = newPosition.y;

    float r  = (float)-AX_DEGREES_TO_RADIANS(rotation + staticRotation);
    float cr = cosf(r);
    float sr = sinf(r);
    float ax = x1 * cr - y1 * sr + x;
    float ay = x1 * sr + y1 * cr + y;
    float bx = x2 * cr - y1 * sr + x;
    float by = x2 * sr + y1 * cr + y;
    float cx = x2 * cr - y2 * sr + x;
    float cy = x2 * sr + y2 * cr + y;
    float dx = x1 * cr - y2 * sr + x;
    float dy = x1 * sr + y2 * cr + y;

    // bottom-left
    quad->bl.vertices.x = ax;
    quad->bl.vertices.y = ay;

    // bottom-right vertex:
    quad->br.vertices.x = bx;
    quad->br.vertices.y = by;

    // top-left vertex:
    quad->tl.vertices.x = dx;
    quad->tl.vertices.y = dy;

    // top-right vertex:
    quad->tr.vertices.x = cx;
    quad->tr.vertices.y = cy;
}

void ParticleSystemQuad::updateParticleQuads()
{