Added text plot support

README.md

@@ -24,9 +24,8 @@ is still being built.
   - [x] Basic hello world
   - [x] Plot flags
 - [ ] Plotting functionality
-  - [ ] Line plot
-    - [x] Single y axis
-    - [ ] Multiple y axes
+  - [x] Line plot
+  - [x] Text plot
   - [ ] Scatter plot
   - [ ] Bar plot
     - [ ] Vertical
@@ -34,7 +33,6 @@ is still being built.
   - [ ] Error bar plot
     - [ ] Vertical
     - [ ] Horizontal
-  - [ ] Text
   - [ ] Heatmap
   - [ ] Pie chart
   - [ ] Digital data

implot-examples/examples/hello_world.rs

@@ -1,5 +1,5 @@
 use imgui::*;
-use implot::{AxisFlags, Plot, PlotFlags, PlotLine};
+use implot::{AxisFlags, Plot, PlotFlags, PlotLine, PlotText};
 
 mod support;
 
@@ -28,14 +28,21 @@ fn main() {
                     .x_limits(0.0, 6.0, Condition::FirstUseEver)
                     .y_limits(-1.0, 3.0, Condition::FirstUseEver)
                     .with_plot_flags(&(PlotFlags::DEFAULT))
-                    .with_y_axis_flags(&(AxisFlags::INVERT))
+                    .with_y_axis_flags(&(AxisFlags::DEFAULT | AxisFlags::INVERT))
                     .build(|| {
+                        // Line plotting
                         PlotLine::new("Left eye").plot(&vec![2.0, 2.0], &vec![2.0, 1.0]);
                         PlotLine::new("Right eye").plot(&vec![4.0, 4.0], &vec![2.0, 1.0]);
-
                         let x_values = vec![1.0, 2.0, 4.0, 5.0];
                         let y_values = vec![1.0, 0.0, 0.0, 1.0];
                         PlotLine::new("Mouth").plot(&x_values, &y_values);
+
+                        // Text
+                        PlotText::new("Text!").plot(2.0, 2.0, false);
+                        PlotText::new("Text with offset!")
+                            .with_pixel_offset(10.0, 30.0)
+                            .plot(2.0, 2.0, false);
+                        PlotText::new("Vertical Text!").plot(0.1, 2.5, true);
                     });
             });
 

src/lib.rs

@@ -320,8 +320,9 @@ pub struct PlotLine {
 }
 
 impl PlotLine {
+    /// Create a new line to be plotted. Does not draw anything yet.
     pub fn new(label: &str) -> Self {
-        PlotLine {
+        Self {
             label: label.to_owned(),
         }
     }
@@ -333,7 +334,7 @@ impl PlotLine {
             return;
         }
         unsafe {
-            implot_sys::ImPlot_PlotLinedoublePtrdoublePtr(
+            sys::ImPlot_PlotLinedoublePtrdoublePtr(
                 im_str!("{}", self.label).as_ptr() as *const i8,
                 x.as_ptr(),
                 y.as_ptr(),
@@ -345,6 +346,61 @@ impl PlotLine {
     }
 }
 
+/// Struct to provide functionality for adding text within a plot
+pub struct PlotText {
+    /// Label to show in plot
+    label: String,
+
+    /// X component of the pixel offset to be used. Will be used independently of the actual plot
+    /// scaling. Defaults to 0.
+    pixel_offset_x: f32,
+
+    /// Y component of the pixel offset to be used. Will be used independently of the actual plot
+    /// scaling. Defaults to 0.
+    pixel_offset_y: f32,
+}
+
+impl PlotText {
+    /// Create a new text label to be shown. Does not draw anything yet.
+    pub fn new(label: &str) -> Self {
+        Self {
+            label: label.into(),
+            pixel_offset_x: 0.0,
+            pixel_offset_y: 0.0,
+        }
+    }
+
+    /// Add a pixel offset to the text to be plotted. This offset will be independent of the
+    /// scaling of the plot itself.
+    pub fn with_pixel_offset(mut self, offset_x: f32, offset_y: f32) -> Self {
+        self.pixel_offset_x = offset_x;
+        self.pixel_offset_y = offset_y;
+        self
+    }
+
+    /// Draw the text label in the plot at the given position, optionally vertically. Use this in
+    /// closures passed to [`Plot::build()`](struct.Plot.html#method.build)
+    pub fn plot(&self, x: f64, y: f64, vertical: bool) {
+        // If there is nothing to show, don't do anything
+        if self.label == "" {
+            return;
+        }
+
+        unsafe {
+            sys::ImPlot_PlotTextdouble(
+                im_str!("{}", self.label).as_ptr() as *const i8,
+                x,
+                y,
+                vertical,
+                sys::ImVec2 {
+                    x: self.pixel_offset_x,
+                    y: self.pixel_offset_y,
+                },
+            );
+        }
+    }
+}
+
 /// 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.