Document AnimatedTexture and bind MAX_FRAMES constant

Closes #24935.

doc/classes/AnimatedTexture.xml

@@ -1,8 +1,12 @@
 <?xml version="1.0" encoding="UTF-8" ?>
 <class name="AnimatedTexture" inherits="Texture" category="Core" version="3.1">
 	<brief_description>
+		Proxy texture for simple frame-based animations.
 	</brief_description>
 	<description>
+		[code]AnimatedTexture[/code] is a resource format for simple frame-based animations, where multiple frames textures can be chained automatically with a predefined delay for each frame. It's not a [Node], contrarily to [AnimationPlayer] or [AnimatedSprite], but has the advantage of being usable at any place where a [Texture] resource can be used, e.g. in a [TileSet].
+		The playback of the animation is controlled by the [member fps] property as well as each frame's optional delay (see [method set_frame_delay]). The animation loops, i.e. it will restart at frame 0 automatically after playing the last frame.
+		[code]AnimatedTexture[/code] currently requires all frame textures to have the same size, otherwise the bigger ones will be cropped to match the smallest one.
 	</description>
 	<tutorials>
 	</tutorials>
@@ -15,6 +19,7 @@
 			<argument index="0" name="frame" type="int">
 			</argument>
 			<description>
+				Retrieves the delayed assigned to the given [code]frame[/code] ID.
 			</description>
 		</method>
 		<method name="get_frame_texture" qualifiers="const">
@@ -23,6 +28,7 @@
 			<argument index="0" name="frame" type="int">
 			</argument>
 			<description>
+				Retrieves the [Texture] assigned to the given [code]frame[/code] ID.
 			</description>
 		</method>
 		<method name="set_frame_delay">
@@ -33,6 +39,14 @@
 			<argument index="1" name="delay" type="float">
 			</argument>
 			<description>
+				Defines an additional delay (in seconds) between this frame and the next one, that will be added to the time interval defined by [member fps]. By default, frames have no delay defined. If a delay value is defined, the final time interval between this frame and the next will be [code]1.0 / fps + delay[/code].
+				For example, for an animation with 3 frames, 2 FPS and a frame delay on the second frame of 1.2, the resulting playback will be:
+				[codeblock]
+				Frame 0: 0.5 s (1 / fps)
+				Frame 1: 1.7 s (1 / fps + 1.2)
+				Frame 2: 0.5 s (1 / fps)
+				Total duration: 2.7 s
+				[/codeblock]
 			</description>
 		</method>
 		<method name="set_frame_texture">
@@ -43,15 +57,23 @@
 			<argument index="1" name="texture" type="Texture">
 			</argument>
 			<description>
+				Assigns a [Texture] to the given [code]frame[/code] ID. IDs start at 0 (so the first frame has ID 0, and the last frame of the animation has ID [member frames] - 1).
+				You can define any frame texture up to [constant MAX_FRAMES], but keep in mind that only frames from 0 to [member frames] - 1 will be part of the animation.
 			</description>
 		</method>
 	</methods>
 	<members>
 		<member name="fps" type="float" setter="set_fps" getter="get_fps">
+			Number of frames per second. This value defines the default time interval between two frames of the animation, and thus the overall duration of the animation loop based on the [member frames] property. A value of 0 means no predefined number of frames per second, the animation will play according to each frame's frame delay (see [method set_frame_delay]). Default value: 4.
+			For example, an animation with 8 frames, no frame delay and a [code]fps[/code] value of 2 will run over 4 seconds, with one frame each 0.5 seconds.
 		</member>
 		<member name="frames" type="int" setter="set_frames" getter="get_frames">
+			Number of frames to use in the animation. While you can create the frames independently with [method set_frame_texture], you need to set this value for the animation to take new frames into account. The maximum number of frames is [constant MAX_FRAMES]. Default value: 1.
 		</member>
 	</members>
 	<constants>
+		<constant name="MAX_FRAMES" value="256">
+			The maximum number of frames supported by [code]AnimatedTexture[/code]. If you need more frames in your animation, use [AnimationPlayer] or [AnimatedSprite].
+		</constant>
 	</constants>
 </class>

scene/resources/texture.cpp

@@ -2000,6 +2000,8 @@ void AnimatedTexture::_bind_methods() {
 		ADD_PROPERTYI(PropertyInfo(Variant::OBJECT, "frame_" + itos(i) + "/texture", PROPERTY_HINT_RESOURCE_TYPE, "Texture", PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_INTERNAL), "set_frame_texture", "get_frame_texture", i);
 		ADD_PROPERTYI(PropertyInfo(Variant::REAL, "frame_" + itos(i) + "/delay_sec", PROPERTY_HINT_RANGE, "0.0,16.0,0.01", PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_INTERNAL), "set_frame_delay", "get_frame_delay", i);
 	}
+
+	BIND_CONSTANT(MAX_FRAMES);
 }
 
 AnimatedTexture::AnimatedTexture() {