[Engine] Is in frustum function for camera

Author: MauroDeryckere

Engine/MauEng/Private/GUI/ImGUILayer.cpp

@@ -82,17 +82,8 @@ namespace MauEng
 				auto v{ scene->GetECSWorld().View<CDebugText, CTransform>() };
 				v.Each([drawList, pos, &viewProj, pWindow, defaultFont, &cameraPos = camera->GetPosition()](CDebugText const& d, CTransform const& t)
 					{
-						glm::vec4 clipSpacePos{ viewProj * glm::vec4{ t.translation, 1.0f } };
-
-						if (clipSpacePos.w != 0.0f)
-						{
-							clipSpacePos /= clipSpacePos.w;
-						}
-
-						float const x{ (clipSpacePos.x * 0.5f + 0.5f) * pWindow->width };
-						float const y{ (clipSpacePos.y * 0.5f + 0.5f) * pWindow->height };
-
-						if (clipSpacePos.z > 0.0f && clipSpacePos.z < 1.0f)
+						auto const res{ Camera::IsInFrustum(t.translation, viewProj, pWindow->width, pWindow->height) };
+						if (res.first)
 						{
 							float const distance{ glm::distance(cameraPos, t.translation) };
 							float const fontSize{ d.scaleWithDistance ? glm::clamp(d.baseFontSize / distance, d.minFontSize, d.maxFontSize)
@@ -116,7 +107,7 @@ namespace MauEng
 								case VerticalAlignment::Bottom: offsetY = -textSize.y; break;
 							}
 
-							drawList->AddText(defaultFont, fontSize,ImVec2{ pos.x + x + offsetX, pos.y + y + offsetY }, IM_COL32(d.colour.r * 255.f, d.colour.g * 255.f, d.colour.b * 255.f, d.colour.a * 255.f), d.text.c_str());
+							drawList->AddText(defaultFont, fontSize,ImVec2{ pos.x + res.second.x + offsetX, pos.y + res.second.y + offsetY }, IM_COL32(d.colour.r * 255.f, d.colour.g * 255.f, d.colour.b * 255.f, d.colour.a * 255.f), d.text.c_str());
 						}
 					});
 			}

Engine/MauEng/Private/Scene/Camera.cpp

@@ -153,4 +153,31 @@ namespace MauEng
 
 		m_EnableExposure = true;
 	}
+
+	std::pair<bool, glm::vec2> Camera::IsInFrustum(glm::vec3 const& pos, glm::mat4 const& viewProj,
+		uint32_t windowWidth, uint32_t windowHeight) noexcept
+	{
+		glm::vec4 clipSpacePos{ viewProj * glm::vec4{ pos, 1.0f } };
+
+		if (clipSpacePos.w != 0.0f)
+		{
+			clipSpacePos /= clipSpacePos.w;
+		}
+
+		float const x{ (clipSpacePos.x * 0.5f + 0.5f) * windowWidth };
+		float const y{ (clipSpacePos.y * 0.5f + 0.5f) * windowHeight };
+
+		if (clipSpacePos.z > 0.0f && clipSpacePos.z < 1.0f)
+		{
+			return { true, glm::vec2{ x, y } };
+		}
+
+		return { false, glm::vec2{ x, y } };
+	}
+
+	std::pair<bool, glm::vec2> Camera::IsInFrustum(glm::vec3 const& pos, uint32_t windowWidth,
+		uint32_t windowHeight) noexcept
+	{
+		return IsInFrustum(pos, m_ViewMatrix * m_ProjectionMatrix, windowWidth, windowHeight);
+	}
 }

Engine/MauEng/Public/Scene/Camera.h

@@ -63,6 +63,11 @@ namespace MauEng
 		void SetCamSettingsSunny16() noexcept;
 		void SetCamSettingsIndoor() noexcept;
 
+		// Returns true if the position is in the frustum, and returns the screen position if it is
+		[[nodiscard]] static std::pair<bool, glm::vec2> IsInFrustum(glm::vec3 const& pos, glm::mat4 const& viewProj, uint32_t windowWidth, uint32_t windowHeight) noexcept;
+		// Returns true if the position is in the frustum, and returns the screen position if it is
+		[[nodiscard]] std::pair<bool, glm::vec2> IsInFrustum(glm::vec3 const& pos, uint32_t windowWidth, uint32_t windowHeight) noexcept;
+
 		Camera(Camera const&) = default;
 		Camera(Camera&&) = default;
 		Camera& operator=(Camera const&) = default;