Add initial prototype.

3-mid/physics/implement/box2d/contrib/testbed/draw.h

@@ -0,0 +1,102 @@
+// MIT License
+
+// Copyright (c) 2019 Erin Catto
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#ifndef DRAW_H
+#define DRAW_H
+
+#define GLFW_INCLUDE_NONE
+#include "glad/gl.h"
+#include "GLFW/glfw3.h"
+
+#include "box2d/box2d.h"
+
+struct b2AABB;
+struct GLRenderPoints;
+struct GLRenderLines;
+struct GLRenderTriangles;
+struct GLFWwindow;
+
+//
+struct Camera
+{
+	Camera()
+	{
+		m_center.Set(0.0f, 20.0f);
+		m_zoom = 1.0f;
+		m_width = 1280;
+		m_height = 800;
+	}
+
+	b2Vec2 ConvertScreenToWorld(const b2Vec2& screenPoint);
+	b2Vec2 ConvertWorldToScreen(const b2Vec2& worldPoint);
+	void BuildProjectionMatrix(float* m, float zBias);
+
+	b2Vec2 m_center;
+	float m_zoom;
+	int32 m_width;
+	int32 m_height;
+};
+
+// This class implements debug drawing callbacks that are invoked
+// inside b2World::Step.
+class DebugDraw : public b2Draw
+{
+public:
+	DebugDraw();
+	~DebugDraw();
+
+	void Create();
+	void Destroy();
+
+	void DrawPolygon(const b2Vec2* vertices, int32 vertexCount, const b2Color& color) override;
+
+	void DrawSolidPolygon(const b2Vec2* vertices, int32 vertexCount, const b2Color& color) override;
+
+	void DrawCircle(const b2Vec2& center, float radius, const b2Color& color) override;
+
+	void DrawSolidCircle(const b2Vec2& center, float radius, const b2Vec2& axis, const b2Color& color) override;
+
+	void DrawSegment(const b2Vec2& p1, const b2Vec2& p2, const b2Color& color) override;
+
+	void DrawTransform(const b2Transform& xf) override;
+
+	void DrawPoint(const b2Vec2& p, float size, const b2Color& color) override;
+
+	void DrawString(int x, int y, const char* string, ...); 
+
+	void DrawString(const b2Vec2& p, const char* string, ...);
+
+	void DrawAABB(b2AABB* aabb, const b2Color& color);
+
+	void Flush();
+
+	bool m_showUI;
+	GLRenderPoints* m_points;
+	GLRenderLines* m_lines;
+	GLRenderTriangles* m_triangles;
+};
+
+extern DebugDraw g_debugDraw;
+extern Camera g_camera;
+extern GLFWwindow* g_mainWindow;
+
+#endif