Add Shapes example

Author: oprypin

examples/README.md

@@ -57,6 +57,13 @@ Parts of the Shader example [from SFML][shader]
     - Set arguments
     - Apply
 
+### [shapes](shapes.cr)
+
+- `VertexArray`
+- `draw` primitives
+- `ConvexShape`
+- Custom `Shape`
+
 ### [gl](gl.cr)
 
 - Basic OpenGL

examples/shapes.cr

@@ -0,0 +1,61 @@
+require "crsfml"
+
+window = SF::RenderWindow.new(
+  SF.video_mode(200, 200), "Shapes",
+  settings: SF.context_settings(depth: 32, antialiasing: 8)
+)
+window.vertical_sync_enabled = true
+
+while window.open?
+  while event = window.poll_event()
+    window.close if event.type == SF::Event::Closed
+  end
+  
+  window.clear SF::Color::Black
+
+  # Top left
+  vertex_array = SF::VertexArray.new(SF::Triangles)
+  vertex_array.append SF.vertex(SF.vector2(0, 0), SF::Color::Green)
+  vertex_array.append SF.vertex(SF.vector2(100, 0), SF::Color::Red)
+  vertex_array.append SF.vertex(SF.vector2(0, 100), SF::Color::Blue)
+  window.draw vertex_array
+
+  # Top right
+  vertices = [
+      SF.vertex(SF.vector2(200, 0), SF::Color::Green),
+      SF.vertex(SF.vector2(100, 0), SF::Color::Red),
+      SF.vertex(SF.vector2(200, 100), SF::Color::Blue),
+  ]
+  window.draw vertices, SF::Triangles, SF.render_states()
+  
+  # Bottom left
+  convex_shape = SF::ConvexShape.new(3)
+  convex_shape[0] = SF.vector2(0, 200)
+  convex_shape[1] = SF.vector2(100, 200)
+  convex_shape[2] = SF.vector2(0, 100)
+  convex_shape.fill_color = SF::Color::Green
+  window.draw convex_shape
+  
+  # Bottom right
+  # broken: https://github.com/manastech/crystal/issues/605
+  class CustomShape < SF::Shape
+    def point_count
+      3
+    end
+    def get_point(i)
+      case i
+      when 0
+        SF.vector2(100, 200)
+      when 1
+        SF.vector2(200, 200)
+      else
+        SF.vector2(200, 100)
+      end
+    end
+  end
+  custom_shape = CustomShape.new()
+  custom_shape.fill_color = SF::Color::Green
+  window.draw custom_shape
+  
+  window.display()
+end