Class: Snow::Vec2Array

Inherits:
Data
  • Object
show all
Includes:
ArrayMarshalSupport, ArraySupport, FiddlePointerSupport, InspectSupport
Defined in:
lib/snow-math/vec2.rb,
lib/snow-math/ptr.rb,
lib/snow-math/to_a.rb,
lib/snow-math/inspect.rb,
lib/snow-math/marshal.rb,
ext/snow-math/snow-math.c

Overview

A contiguous array of Vec2s. Allocated as a single block of memory so that it can easily be passed back to C libraries (like OpenGL) and to aid with cache locality.

Useful also to represent texture coordinates and 2D positions and displacements.

Class Method Summary collapse

Instance Method Summary collapse

Methods included from ArrayMarshalSupport

#_dump, included

Methods included from InspectSupport

#inspect

Methods included from ArraySupport

#each, #map, #map!, #to_a

Methods included from FiddlePointerSupport

#to_ptr

Class Method Details

.new(sm_length_or_copy) ⇒ Object Also known as: []

In the first form, a new typed array of Vec2 elements is allocated and returned. In the second form, a copy of a typed array of Vec2 objects is made and returned. Copied arrays do not share data.

call-seq:

new(size)       -> new vec2_array
new(vec2_array) -> copy of vec2_array



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# File 'ext/snow-math/snow-math.c', line 159

static VALUE sm_vec2_array_new(VALUE sm_self, VALUE sm_length_or_copy)
{
  size_t length = 0;
  vec2_t *arr;
  VALUE sm_type_array;
  int copy_array = 0;
  if ((copy_array = SM_IS_A(sm_length_or_copy, vec2_array))) {
    length = NUM2SIZET(sm_mathtype_array_length(sm_length_or_copy));
  } else {
    length = NUM2SIZET(sm_length_or_copy);
  }
  if (length <= 0) {
    return Qnil;
  }
  arr = ALLOC_N(vec2_t, length);
  if (copy_array) {
    const vec2_t *source;
    Data_Get_Struct(sm_length_or_copy, vec2_t, source);
    MEMCPY(arr, source, vec2_t, length);
    sm_length_or_copy = sm_mathtype_array_length(sm_length_or_copy);
    sm_self = rb_obj_class(sm_length_or_copy);
  }
  sm_type_array = Data_Wrap_Struct(sm_self, 0, free, arr);
  rb_ivar_set(sm_type_array, kRB_IVAR_MATHARRAY_LENGTH, sm_length_or_copy);
  rb_ivar_set(sm_type_array, kRB_IVAR_MATHARRAY_CACHE, rb_ary_new2((long)length));
  rb_obj_call_init(sm_type_array, 0, 0);
  return sm_type_array;
}

Instance Method Details

#address ⇒ Object

Returns the memory address of the object.

call-seq: address -> fixnum



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# File 'ext/snow-math/snow-math.c', line 6683

static VALUE sm_get_address(VALUE sm_self)
{
  void *data_ptr = NULL;
  Data_Get_Struct(sm_self, void, data_ptr);
  return ULL2NUM((unsigned long long)data_ptr);
}

#dup ⇒ Object Also known as: clone

Duplicates the Vec2Array and returns it.

call-seq: dup -> new vec3_array



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# File 'lib/snow-math/to_a.rb', line 126

def dup
  self.class.new(self)
end

#fetch(sm_index) ⇒ Object Also known as: []

Fetches a Vec2 from the array at the index and returns it. The returned Vec2 may be a cached object. In all cases, values returned from a typed array are associated with the memory of the array and not given their own memory. So, modifying a Vec2 fetched from an array modifies the array’s data.

As a result, objects returned by a Vec2Array should not be considered thread-safe, nor should manipulating a Vec2Array be considered thread-safe either. If you want to work with data returned from an array without altering the array data, you should call Vec2#dup or Vec2#copy to get a new Vec2 with a copy of the array object’s data.

call-seq: fetch(index) -> vec2



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# File 'ext/snow-math/snow-math.c', line 250

static VALUE sm_vec2_array_fetch(VALUE sm_self, VALUE sm_index)
{
  vec2_t *arr;
  size_t length = NUM2SIZET(sm_mathtype_array_length(sm_self));
  size_t index = NUM2SIZET(sm_index);
  VALUE sm_inner;
  VALUE sm_cache;
  if (index >= length) {
    rb_raise(rb_eRangeError,
      "Index %zu out of bounds for array with length %zu",
      index, length);
  }

  sm_cache = rb_ivar_get(sm_self, kRB_IVAR_MATHARRAY_CACHE);
  if (!RTEST(sm_cache)) {
    rb_raise(rb_eRuntimeError, "No cache available");
  }
  sm_inner = rb_ary_entry(sm_cache, (long)index);

  if (!RTEST(sm_inner)) {
    /* No cached value, create one. */
    Data_Get_Struct(sm_self, vec2_t, arr);
    sm_inner = Data_Wrap_Struct(s_sm_vec2_klass, 0, 0, arr[index]);
    rb_ivar_set(sm_inner, kRB_IVAR_MATHARRAY_SOURCE, sm_self);
    /* Store the Vec2 in the cache */
    rb_ary_store(sm_cache, (long)index, sm_inner);
  }

  return sm_inner;
}

#length ⇒ Object

Returns the array’s length.

call-seq: length -> fixnum



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# File 'ext/snow-math/snow-math.c', line 84

static VALUE sm_mathtype_array_length(VALUE sm_self)
{
  return rb_ivar_get(sm_self, kRB_IVAR_MATHARRAY_LENGTH);
}

#resize!(sm_new_length) ⇒ Object

Resizes the array to new_length and returns self.

If resizing to a length smaller than the previous length, excess array elements are discarded and the array is truncated. Otherwise, when resizing the array to a greater length than previous, new elements in the array will contain garbage values.

If new_length is equal to self.length, the call does nothing to the array.

Attempting to resize an array to a new length of zero or less will raise a RangeError. Do not try to resize arrays to zero or less. Do not be that person.

call-seq:

resize!(new_length) -> self



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# File 'ext/snow-math/snow-math.c', line 207

static VALUE sm_vec2_array_resize(VALUE sm_self, VALUE sm_new_length)
{
  size_t new_length;
  size_t old_length;

  rb_check_frozen(sm_self);

  old_length = NUM2SIZET(sm_mathtype_array_length(sm_self));
  new_length = NUM2SIZET(sm_new_length);

  if (old_length == new_length) {
    /* No change, done */
    return sm_self;
  } else if (new_length < 1) {
    /* Someone decided to be that person. */
    rb_raise(rb_eRangeError,
      "Cannot resize array to length less than or equal to 0.");
    return sm_self;
  }

  REALLOC_N(RDATA(sm_self)->data, vec2_t, new_length);
  rb_ivar_set(sm_self, kRB_IVAR_MATHARRAY_LENGTH, sm_new_length);
  rb_ary_clear(rb_ivar_get(sm_self, kRB_IVAR_MATHARRAY_CACHE));

  return sm_self;
}

#size ⇒ Object

Returns the length of the array.

call-seq: length -> fixnum



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# File 'ext/snow-math/snow-math.c', line 328

static VALUE sm_vec2_array_size(VALUE sm_self)
{
  size_t length = NUM2SIZET(sm_mathtype_array_length(sm_self));
  return SIZET2NUM(length * sizeof(vec2_t));
}

#store(sm_index, sm_value) ⇒ Object Also known as: []=

Stores a Vec2 at the given index. If the provided Vec2 is a member of the array and stored at the index, then no copy is done, otherwise the Vec2 is copied to the array.

call-seq: store(index, value) -> value



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# File 'ext/snow-math/snow-math.c', line 290

static VALUE sm_vec2_array_store(VALUE sm_self, VALUE sm_index, VALUE sm_value)
{
  vec2_t *arr;
  vec2_t *value;
  size_t length = NUM2SIZET(sm_mathtype_array_length(sm_self));
  size_t index = NUM2SIZET(sm_index);

  rb_check_frozen(sm_self);

  if (index >= length) {
    rb_raise(rb_eRangeError,
      "Index %zu out of bounds for array with length %zu",
      index, length);
  } else if (!SM_IS_A(sm_value, vec2) && !SM_IS_A(sm_value, vec3) && !SM_IS_A(sm_value, vec4) && !SM_IS_A(sm_value, quat)) {
    rb_raise(rb_eTypeError,
      "Invalid value to store: expected Vec2, Vec3, Vec4, or Quat, got %s",
      rb_obj_classname(sm_value));
  }

  Data_Get_Struct(sm_self, vec2_t, arr);
  value = sm_unwrap_vec2(sm_value, NULL);

  if (value == &arr[index]) {
    /* The object's part of the array, don't bother copying */
    return sm_value;
  }

  vec2_copy(*value, arr[index]);
  return sm_value;
}