Refactored Plot building, various example updates

src/lib.rs

@@ -1,11 +1,30 @@
 //! # Rust bindings to ImPlot
 //!
-//! This crate contains idiomatic bindings to the C++ implot library, which
-//! use the bindings exposed by the `implot-sys` crate.
+//! This crate contains idiomatic bindings to the C++ [implot library](https://github.com/epezent/implot),
+//! which use the bindings exposed by the `implot-sys` crate. An attempt is made to keep
+//! documentation here somewhat self-contained, but when in doubt, the documentation of implot
+//! itself (in particular also the demo code [here](https://github.com/epezent/implot/blob/master/implot_demo.cpp))
+//! should help as well.
+//!
+//!
 pub extern crate implot_sys as sys;
 use sys::imgui::im_str;
 
-/// Struct to represent an ImPlot.
+/// Struct to represent an ImPlot. This is the main construct used to contain all kinds of plots in ImPlot.
+///
+/// `Plot` is to be used (within an imgui window) with the following pattern:
+/// ```rust
+/// # // This doctest fails because we don't have an imgui context to run things in here
+/// # use implot;
+/// implot::Plot::new("my title")
+///     .size(300.0, 200.0) // other things such as .x_label("some_label") can be added too
+///     .build( || {
+///         // Do things such as plotting lines
+///     });
+///
+/// ```
+/// (If you are coming from the C++ implementation or the C bindings: build() calls both
+/// begin() and end() internally)
 pub struct Plot {
     /// Title of the plot, shown on top.
     title: String,
@@ -13,10 +32,10 @@ pub struct Plot {
     x_label: String,
     /// Label of the y axis, shown on the left
     y_label: String,
-    /// Size of the plot in x direction, in pixels.
-    size_x: u32,
-    /// Size of the plot in y direction, in pixels.
-    size_y: u32,
+    /// Size of the plot in x direction, in the same units imgui uses.
+    size_x: f32,
+    /// Size of the plot in y direction, in the same units imgui uses.
+    size_y: f32,
     /// Flags relating to the plot TODO(4bb4) make those into bitflags
     plot_flags: sys::ImPlotFlags,
     /// Flags relating to the first x axis of the plot TODO(4bb4) make those into bitflags
@@ -33,25 +52,48 @@ pub struct Plot {
 
 impl Plot {
     /// Create a new plot with some defaults set. Does not draw anything yet.
-    pub fn new() -> Self {
+    pub fn new(title: &str) -> Self {
         // TODO(4bb4) question these defaults, maybe remove some of them
         Self {
-            title: "".to_owned(),
+            title: title.to_owned(),
             x_label: "".to_owned(),
             y_label: "".to_owned(),
-            size_x: 400,
-            size_y: 400,
-            plot_flags: 0xFF,
-            x_flags: 7,
-            y_flags: 7,
-            x2_flags: 0,
-            y2_flags: 0,
+            size_x: 400.0,
+            size_y: 400.0,
+            plot_flags: 0xFF, // TODO(4bb4) define the defaults better
+            x_flags: 7,       // TODO(4bb4) define the defaults better
+            y_flags: 7,       // TODO(4bb4) define the defaults better
+            x2_flags: 0,      // TODO(4bb4) define the defaults better
+            y2_flags: 0,      // TODO(4bb4) define the defaults better
         }
     }
 
+    /// Sets the plot size, given as [size_x, size_y]. Units are the same as
+    /// what imgui uses. TODO(4b4) ... which is? I'm not sure it's pixels
+    #[inline]
+    pub fn size(mut self, size_x: f32, size_y: f32) -> Self {
+        self.size_x = size_x;
+        self.size_y = size_y;
+        self
+    }
+
+    /// Set the x label of the plot
+    #[inline]
+    pub fn x_label(mut self, label: &str) -> Self {
+        self.x_label = label.to_owned();
+        self
+    }
+
+    /// Set the y label of the plot
+    #[inline]
+    pub fn y_label(mut self, label: &str) -> Self {
+        self.y_label = label.to_owned();
+        self
+    }
+
     /// Attempt to show the plot. Only do things with it and call `end()` after that
-    /// if this returns `true`.
-    pub fn begin(&self) -> bool {
+    /// if this returns `true`. Not to be used directly, use `build` instead.
+    fn begin(&self) -> bool {
         unsafe {
             sys::ImPlot_BeginPlot(
                 im_str!("{}", self.title).as_ptr(),
@@ -70,14 +112,25 @@ impl Plot {
         }
     }
 
-    /// End a previously-`begin()`ed plot. Only call if `begin()` returned `true`.
-    pub fn end(&self) {
+    /// End (this) plot. This gets called from build()
+    fn end(&self) {
         unsafe { sys::ImPlot_EndPlot() }
     }
+
+    /// Creates a window and runs a closure to construct the contents.
+    ///
+    /// Note: the closure is not called if ImPlot::BeginPlot() returned
+    /// false - TODO(4bb4) figure out if this is if things are not rendered
+    pub fn build<F: FnOnce()>(self, f: F) {
+        if self.begin() {
+            f();
+            self.end()
+        }
+    }
 }
 
 // TODO(4bb4) convert to struct and add methods to set title and flags
-/// Plot a line. Use this between Plot::begin() and Plot::end().
+/// Plot a line. Use this in closures passed to [`Plot::build()`](struct.Plot.html#method.build)
 pub fn plot_line(x: &Vec<f64>, y: &Vec<f64>, label: &str) {
     unsafe {
         implot_sys::ImPlot_PlotLinedoublePtrdoublePtr(
@@ -90,3 +143,13 @@ pub fn plot_line(x: &Vec<f64>, y: &Vec<f64>, label: &str) {
         );
     }
 }
+
+/// Show the demo window for poking around what functionality implot has to
+/// offer. Note that not all of this is necessarily implemented in implot-rs
+/// already - if you find something missing you'd really like, raise an issue.
+// This requires implot_demo.cpp to be in the list of sources in implot-sys.
+pub fn show_demo_window(show: &mut bool) {
+    unsafe {
+        implot_sys::ImPlot_ShowDemoWindow(show);
+    }
+}