From 1bbd3e0c1817774335c97f4c59e0310b61949ece Mon Sep 17 00:00:00 2001
From: crupest <crupest@outlook.com>
Date: Mon, 29 Nov 2021 15:23:01 +0800
Subject: ...

---
 demos/graphics_experiments/1.cpp | 79 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 demos/graphics_experiments/1.cpp

(limited to 'demos/graphics_experiments/1.cpp')

diff --git a/demos/graphics_experiments/1.cpp b/demos/graphics_experiments/1.cpp
new file mode 100644
index 00000000..51411f12
--- /dev/null
+++ b/demos/graphics_experiments/1.cpp
@@ -0,0 +1,79 @@
+// Code referred from
+// https://iq.opengenus.org/bresenham-line-drawining-algorithm/
+
+#include "cru/platform/Color.hpp"
+#include "cru/platform/bootstrap/Bootstrap.hpp"
+#include "cru/platform/graphics/Factory.hpp"
+#include "cru/platform/graphics/Painter.hpp"
+#include "cru/platform/gui/UiApplication.hpp"
+#include "cru/platform/gui/Window.hpp"
+
+#include <functional>
+
+void BresenhamDrawLine(int x1, int y1, int x2, int y2,
+                       const std::function<void(int, int)>& draw_pixel) {
+  // calculating range for line between start and end point
+  int dx = x2 - x1;
+  int dy = y2 - y1;
+
+  int x = x1;
+  int y = y1;
+
+  // this is the case when slope(m) < 1
+  if (abs(dx) > abs(dy)) {
+    draw_pixel(x, y);  // this putpixel is for very first pixel of the line
+    int pk = (2 * abs(dy)) - abs(dx);
+
+    for (int i = 0; i < abs(dx); i++) {
+      x = x + 1;
+      if (pk < 0)
+        pk = pk + (2 * abs(dy));
+      else {
+        y = y + 1;
+        pk = pk + (2 * abs(dy)) - (2 * abs(dx));
+      }
+      draw_pixel(x, y);
+    }
+  } else {
+    // this is the case when slope is greater than or equal to 1  i.e: m>=1
+    draw_pixel(x, y);  // this putpixel is for very first pixel of the line
+    int pk = (2 * abs(dx)) - abs(dy);
+
+    for (int i = 0; i < abs(dy); i++) {
+      y = y + 1;
+      if (pk < 0)
+        pk = pk + (2 * abs(dx));
+      else {
+        x = x + 1;
+        pk = pk + (2 * abs(dx)) - (2 * abs(dy));
+      }
+
+      draw_pixel(x, y);  // display pixel at coordinate (x, y)
+    }
+  }
+}
+
+int main() {
+  auto application = cru::platform::bootstrap::CreateUiApplication();
+  auto window = application->CreateWindow();
+
+  auto brush = application->GetGraphicsFactory()->CreateSolidColorBrush(
+      cru::platform::colors::black);
+
+  window->SetClientSize(cru::platform::Size(400, 200));
+
+  window->PaintEvent()->AddHandler([window, &brush](nullptr_t) {
+    auto painter = window->BeginPaint();
+    auto draw_pixel = [&painter, &brush](int x, int y) {
+      painter->FillRectangle({static_cast<float>(x) - 0.5f,
+                              static_cast<float>(y) - 0.5f, 1.0f, 1.0f},
+                             brush.get());
+    };
+    BresenhamDrawLine(50, 50, 100, 200, draw_pixel);
+    BresenhamDrawLine(50, 50, 200, 100, draw_pixel);
+  });
+
+  window->SetVisibility(cru::platform::gui::WindowVisibilityType::Show);
+
+  return application->Run();
+}
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