godotengine
/
godot
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

This PR handles the smoothstep degenerate case where the range is empty. 

It also updates the documentation to describe positive and negative ranges.

Co-Authored-By: Hugo Locurcio <hugo.locurcio@hugo.pro>
Co-Authored-By: kleonc <9283098+kleonc@users.noreply.github.com>
This commit is contained in:
Malcolm Nixon 2024-06-14 03:08:16 -04:00
parent ee363af0ed
commit 23fc704cbc
2 changed files with 14 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
core/math/math_funcs.h
View File

@ -447,14 +447,22 @@ public:
static _ALWAYS_INLINE_ double smoothstep(double p_from, double p_to, double p_s) {
if (is_equal_approx(p_from, p_to)) {
return p_from;
if (likely(p_from <= p_to)) {
return p_s <= p_from ? 0.0 : 1.0;
} else {
return p_s <= p_to ? 1.0 : 0.0;
}
}
double s = CLAMP((p_s - p_from) / (p_to - p_from), 0.0, 1.0);
return s * s * (3.0 - 2.0 * s);
}
static _ALWAYS_INLINE_ float smoothstep(float p_from, float p_to, float p_s) {
if (is_equal_approx(p_from, p_to)) {
return p_from;
if (likely(p_from <= p_to)) {
return p_s <= p_from ? 0.0f : 1.0f;
} else {
return p_s <= p_to ? 1.0f : 0.0f;
}
}
float s = CLAMP((p_s - p_from) / (p_to - p_from), 0.0f, 1.0f);
return s * s * (3.0f - 2.0f * s);

6
doc/classes/@GlobalScope.xml
View File

@ -1248,8 +1248,9 @@
<param index="1" name="to" type="float" />
<param index="2" name="x" type="float" />
<description>
Returns the result of smoothly interpolating the value of [param x] between [code]0[/code] and [code]1[/code], based on the where [param x] lies with respect to the edges [param from] and [param to].
The return value is [code]0[/code] if [code]x &lt;= from[/code], and [code]1[/code] if [code]x &gt;= to[/code]. If [param x] lies between [param from] and [param to], the returned value follows an S-shaped curve that maps [param x] between [code]0[/code] and [code]1[/code].
Returns a smooth cubic Hermite interpolation between [code]0[/code] and [code]1[/code].
For positive ranges (when [code]from &lt;= to[/code]) the return value is [code]0[/code] when [code]x &lt;= from[/code], and [code]1[/code] when [code]x &gt;= to[/code]. If [param x] lies between [param from] and [param to], the return value follows an S-shaped curve that smoothly transitions from [code]0[/code] to [code]1[/code].
For negative ranges (when [code]from &gt; to[/code]) the function is mirrored and returns [code]1[/code] when [code]x &lt;= to[/code] and [code]0[/code] when [code]x &gt;= from[/code].
This S-shaped curve is the cubic Hermite interpolator, given by [code]f(y) = 3*y^2 - 2*y^3[/code] where [code]y = (x-from) / (to-from)[/code].
[codeblock]
smoothstep(0, 2, -5.0) # Returns 0.0
@ -1259,6 +1260,7 @@
[/codeblock]
Compared to [method ease] with a curve value of [code]-1.6521[/code], [method smoothstep] returns the smoothest possible curve with no sudden changes in the derivative. If you need to perform more advanced transitions, use [Tween] or [AnimationPlayer].
[url=https://raw.githubusercontent.com/godotengine/godot-docs/master/img/smoothstep_ease_comparison.png]Comparison between smoothstep() and ease(x, -1.6521) return values[/url]
[url=https://raw.githubusercontent.com/godotengine/godot-docs/master/img/smoothstep_range.webp]Smoothstep() return values with positive, zero, and negative ranges[/url]
</description>
</method>
<method name="snapped">