Merge branch 'model-docs'

Adds a manpage describing the model format.

docs/model-format.man

@@ -0,0 +1,131 @@
+.TH FC2D_MODEL 5 "Facecam2D Model Format 0.3 Manual"
+.
+.SH NAME
+fc2d_model \- Facecam2D model file format
+.
+.
+.SH DESCRIPTION
+Facecam2D uses
+.B zip
+archive files using the
+.I .fma (Facecam2D model archive)
+file extension, to store models.
+.
+These zip files contain a mandatory
+.I toml
+file called
+.B model.toml,
+which describes the model and its parts.
+.
+This file is called the
+.B model descriptor.
+.
+Any model file that does not contain
+.B model.toml
+in the root of the archive is invalid.
+.
+.PP
+Example
+.B model.toml:
+.
+.sp
+.
+.EX
+[format]
+version_major = 0
+version_minor = 3
+
+[model_info]
+name = "Example Model"
+version = "1.0"
+
+[[part]]
+texture = "tex/head.png"
+bind = "head"
+
+[[part]]
+bind = "head"
+follow = "face"
+factor = 0.75
+
+	[[textures]]
+	file = "tex/face-closedmouth.png"
+
+	[[textures]]
+	file = "tex/face-openmouth.png"
+	trigger = "mouth-open"
+.EE
+.
+.PP
+.
+In addition to the model descriptor, the model archive can contain other
+files (e.g. textures) that can be anywhere in the archive, including the root.
+.
+Unnecessary files should not be present in the archive, but archives with
+unnecessary files are still valid.
+.
+.
+.SH KEYS
+.SS format
+.TP
+version_major
+Integer: Major version of the model format (e.g. 0 for v0.3).
+.
+.TP
+version_minor
+Integer: Minor version of the model format (e.g. 3 for v0.3).
+.
+.
+.SS model_info
+.TP
+name
+String: The name of the model (will be displayed in the window title).
+.
+.TP
+version
+String: A version string for the model (currently unused).
+.
+.
+.SS part
+.TP
+texture
+String: Path to a texture file in the archive. Required if
+.B [[textures]]
+is not present in the part.
+.
+.TP
+bind
+String: A bind point which the part will be bound to.
+Possible values: null, head, face
+.
+.TP
+follow
+String: A bind point which the part will follow depending on
+.B factor.
+The part will copy the position of
+.B bind
+but move in the direction of
+.B follow.
+.
+.TP
+factor
+Float: How far the part will move towards the
+.B follow
+point.
+If negative, the part will move in the opposite direction.
+.
+.SS textures
+.TP
+file
+Path to a texture file in the archive. Required if
+.B texture
+is not present in the part.
+.
+.TP
+trigger
+A trigger that will cause the part to use this texture.
+Possible values: null, mouth-open
+.
+.PP
+When specifying multiple textures, the first one specified
+will be used by default.