...

5 files changed, 120 insertions, 0 deletions

diff --git a/include/cru/platform/matrix.hpp b/include/cru/platform/matrix.hpp
new file mode 100644
index 00000000..e5e5cf42
--- /dev/null
+++ b/include/cru/platform/matrix.hpp
@@ -0,0 +1,84 @@
+#include "cru/common/pre_config.hpp"
+
+#include "cru/common/ui_base.hpp"
+
+#include <cmath>
+
+namespace cru::platform {
+struct Matrix {
+  float m11;
+  float m12;
+  float m21;
+  float m22;
+  float m31;
+  float m32;
+
+  Matrix() {}
+
+  Matrix(float m11, float m12, float m21, float m22, float m31, float m32) {
+    this->m11 = m11;
+    this->m12 = m12;
+    this->m21 = m21;
+    this->m22 = m22;
+    this->m31 = m31;
+    this->m32 = m32;
+  }
+
+  bool IsIdentity() const {
+    return m11 == 1.0f && m12 == 0.0f && m21 == 0.0f && m22 == 1.0f &&
+           m31 == 0.0f && m32 == 0.0f;
+  }
+
+  Matrix& operator*=(const Matrix& matrix) const {
+    *this = Product(*this, matrix);
+    return *this;
+  }
+
+  Matrix operator*(const Matrix& matrix) const { return Product(this, matrix); }
+
+  ui::Point TransformPoint(const ui::Point& point) const {
+    return ui::Point{point.x * m11 + point.y * m21 + m31,
+                     point.x * m12 + point.y * m22 + m32};
+  }
+
+  static Matrix Identity() {
+    return Matrix{1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f};
+  }
+
+  static Matrix Translation(float x, float y) {
+    return Matrix{1.0f, 0.0f, 0.0f, 1.0f, x, y};
+  }
+
+  static Matrix Scale(float sx, float sy) { return Scale(sx, sy, 0.0f, 0.0f); }
+
+  static Matrix Scale(float sx, float sy, float cx, float cy) {
+    return Matrix{sx, 0.0f, 0.0f, sy, cx - sx * cx, cy - sy * cy};
+  }
+
+  static Matrix Rotation(float angle) {
+    float r = AngleToRadian(angle);
+    float s = std::sinf(r);
+    float c = std::cosf(r);
+
+    return Matrix{c, s, -s, c, 0.0f, 0.0f};
+  }
+
+  static Matrix Skew(float sx, float sy) {
+    return Matrix{1.0f, sx, sy, 1.0f, 0.0f, 0.0f};
+  }
+
+  static Matrix Product(const Matrix& a, const Matrix& b) {
+    return Matrix{a.m11 * b.m11 + a.m12 * b.m21,
+                  a.m11 * b.m12 + a.m12 * b.m22,
+                  a.m21 * b.m11 + a.m22 * b.m21,
+                  a.m21 * b.m12 + a.m22 * b.m22,
+                  a.m31 * b.m11 + a.m32 * b.m21 + b.m31,
+                  a.m31 * b.m12 + a.m32 * b.m22 + b.m32};
+  }
+
+ private:
+  static constexpr float PI = 3.1415926535f;
+
+  static float AngleToRadian(float angle) { return angle / 180.f * PI; }
+};
+}  // namespace cru::platform
diff --git a/include/cru/platform/painter.hpp b/include/cru/platform/painter.hpp
index 77ca5098..2e979184 100644
--- a/include/cru/platform/painter.hpp
+++ b/include/cru/platform/painter.hpp
@@ -2,12 +2,15 @@
 #include "cru/common/base.hpp"
 
 #include "cru/common/ui_base.hpp"
+#include "matrix.hpp"
 
 namespace cru::platform {
 struct Brush;
 struct Geometry;
 
 struct Painter : virtual Interface {
+  virtual Matrix GetTransform() = 0;
+  virtual void SetTransform(const Matrix& matrix) = 0;
   virtual void StrokeGeometry(Geometry* geometry, Brush* brush,
                               float width) = 0;
   virtual void FillGeometry(Geometry* geometry, Brush* brush) = 0;
diff --git a/include/cru/platform/painter_util.hpp b/include/cru/platform/painter_util.hpp
new file mode 100644
index 00000000..fed0c487
--- /dev/null
+++ b/include/cru/platform/painter_util.hpp
@@ -0,0 +1,14 @@
+#pragma once
+#include "painter.hpp"
+
+#include <functional>
+
+namespace cru::platform::util {
+inline void WithTransform(Painter* painter, const Matrix& matrix,
+                   const std::function<void(Painter*)>& action) {
+  const auto old = painter->GetTransform();
+  painter->SetTransform(old * matrix);
+  action(painter);
+  painter->SetTransform(old);
+}
+}
diff --git a/include/cru/platform/win/d2d_util.hpp b/include/cru/platform/win/d2d_util.hpp
index 9ff6556a..51aea4f8 100644
--- a/include/cru/platform/win/d2d_util.hpp
+++ b/include/cru/platform/win/d2d_util.hpp
@@ -1,9 +1,21 @@
 #pragma once
 #include "win_pre_config.hpp"
 
+#include "../matrix.hpp"
 #include "cru/common/ui_base.hpp"
 
 namespace cru::platform::win::util {
+inline D2D1_MATRIX_3X2_F Convert(const Matrix& matrix) {
+  D2D1_MATRIX_3X2_F m;
+  m._11 = matrix.m11;
+  m._12 = matrix.m12;
+  m._21 = matrix.m21;
+  m._22 = matrix.m22;
+  m._31 = matrix.m31;
+  m._32 = matrix.m32;
+  return m;
+}
+
 inline D2D1_COLOR_F Convert(const ui::Color& color) {
   return D2D1::ColorF(color.red / 255.0f, color.green / 255.0f,
                       color.blue / 255.0f, color.alpha / 255.0f);
@@ -28,6 +40,11 @@ inline D2D1_ELLIPSE Convert(const ui::Ellipse& ellipse) {
                        ellipse.radius_y);
 }
 
+inline Matrix Convert(const D2D1_MATRIX_3X2_F& matrix) {
+  return Matrix{matrix._11, matrix._12, matrix._21,
+                matrix._22, matrix._31, matrix._32};
+}
+
 inline ui::Color Convert(const D2D1_COLOR_F& color) {
   auto floor = [](float n) { return static_cast<std::uint8_t>(n + 0.5f); };
   return ui::Color{floor(color.r * 255.0f), floor(color.g * 255.0f),
diff --git a/include/cru/platform/win/win_painter.hpp b/include/cru/platform/win/win_painter.hpp
index 7b71ccbd..1e449d85 100644
--- a/include/cru/platform/win/win_painter.hpp
+++ b/include/cru/platform/win/win_painter.hpp
@@ -15,6 +15,8 @@ class WinPainter : public Object, public virtual Painter {
   WinPainter& operator=(WinPainter&& other) = delete;
   ~WinPainter() override;
 
+  Matrix GetTransform() override;
+  void SetTransform(const Matrix& matrix) override;
   void StrokeGeometry(Geometry* geometry, Brush* brush, float width) override;
   void FillGeometry(Geometry* geometry, Brush* brush) override;
   void EndDraw() override;