UI: Update multiview safe areas

Make the safe areas respect the EBU R 95 and Rec. ITU-R BT.1848-1
standards for 16:9 content.
Links: https://tech.ebu.ch/docs/r/r095rev1_March2016.pdf and
https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.1848-1-201510-I!!PDF-E.pdf

UI/window-projector.cpp

@@ -82,37 +82,50 @@ OBSProjector::OBSProjector(QWidget *widget, obs_source_t *source_, int monitor,
 	if (type == ProjectorType::Multiview) {
 		obs_enter_graphics();
 
+		// All essential action should be placed inside this area
 		gs_render_start(true);
-		gs_vertex2f(0.04f, 0.04f);
-		gs_vertex2f(0.04f, 0.96f);
-		gs_vertex2f(0.96f, 0.96f);
-		gs_vertex2f(0.96f, 0.04f);
-		gs_vertex2f(0.04f, 0.04f);
-		innerBox = gs_render_save();
-
+		gs_vertex2f(actionSafePercentage, actionSafePercentage);
+		gs_vertex2f(actionSafePercentage, 1 - actionSafePercentage);
+		gs_vertex2f(1 - actionSafePercentage, 1 - actionSafePercentage);
+		gs_vertex2f(1 - actionSafePercentage, actionSafePercentage);
+		gs_vertex2f(actionSafePercentage, actionSafePercentage);
+		actionSafeMargin = gs_render_save();
+
+		// All graphics should be placed inside this area
 		gs_render_start(true);
-		gs_vertex2f(0.15f, 0.04f);
-		gs_vertex2f(0.15f, 0.96f);
-		leftVLine = gs_render_save();
-
+		gs_vertex2f(graphicsSafePercentage, graphicsSafePercentage);
+		gs_vertex2f(graphicsSafePercentage, 1 - graphicsSafePercentage);
+		gs_vertex2f(1 - graphicsSafePercentage,
+				1 - graphicsSafePercentage);
+		gs_vertex2f(1 - graphicsSafePercentage, graphicsSafePercentage);
+		gs_vertex2f(graphicsSafePercentage, graphicsSafePercentage);
+		graphicsSafeMargin = gs_render_save();
+
+		// 4:3 safe area for widescreen
 		gs_render_start(true);
-		gs_vertex2f(0.85f, 0.04f);
-		gs_vertex2f(0.85f, 0.96f);
-		rightVLine = gs_render_save();
+		gs_vertex2f(fourByThreeSafePercentage, graphicsSafePercentage);
+		gs_vertex2f(1 - fourByThreeSafePercentage,
+				graphicsSafePercentage);
+		gs_vertex2f(1 - fourByThreeSafePercentage, 1 -
+				graphicsSafePercentage);
+		gs_vertex2f(fourByThreeSafePercentage,
+				1 - graphicsSafePercentage);
+		gs_vertex2f(fourByThreeSafePercentage, graphicsSafePercentage);
+		fourByThreeSafeMargin = gs_render_save();
 
 		gs_render_start(true);
 		gs_vertex2f(0.0f, 0.5f);
-		gs_vertex2f(0.075f, 0.5f);
+		gs_vertex2f(lineLength, 0.5f);
 		leftLine = gs_render_save();
 
 		gs_render_start(true);
 		gs_vertex2f(0.5f, 0.0f);
-		gs_vertex2f(0.5f, 0.09f);
+		gs_vertex2f(0.5f, lineLength);
 		topLine = gs_render_save();
 
 		gs_render_start(true);
-		gs_vertex2f(0.925f, 0.5f);
 		gs_vertex2f(1.0f, 0.5f);
+		gs_vertex2f(1 - lineLength, 0.5f);
 		rightLine = gs_render_save();
 		obs_leave_graphics();
 
@@ -152,9 +165,9 @@ OBSProjector::~OBSProjector()
 		}
 
 		obs_enter_graphics();
-		gs_vertexbuffer_destroy(innerBox);
-		gs_vertexbuffer_destroy(leftVLine);
-		gs_vertexbuffer_destroy(rightVLine);
+		gs_vertexbuffer_destroy(actionSafeMargin);
+		gs_vertexbuffer_destroy(graphicsSafeMargin);
+		gs_vertexbuffer_destroy(fourByThreeSafeMargin);
 		gs_vertexbuffer_destroy(leftLine);
 		gs_vertexbuffer_destroy(topLine);
 		gs_vertexbuffer_destroy(rightLine);
@@ -537,9 +550,9 @@ void OBSProjector::OBSRenderMultiview(void *data, uint32_t cx, uint32_t cy)
 		obs_source_video_render(previewSrc);
 	else
 		obs_render_main_texture();
-	renderVB(window->innerBox, targetCX, targetCY, outerColor);
-	renderVB(window->leftVLine, targetCX, targetCY, outerColor);
-	renderVB(window->rightVLine, targetCX, targetCY, outerColor);
+	renderVB(window->actionSafeMargin, targetCX, targetCY, outerColor);
+	renderVB(window->graphicsSafeMargin, targetCX, targetCY, outerColor);
+	renderVB(window->fourByThreeSafeMargin, targetCX, targetCY, outerColor);
 	renderVB(window->leftLine, targetCX, targetCY, outerColor);
 	renderVB(window->topLine, targetCX, targetCY, outerColor);
 	renderVB(window->rightLine, targetCX, targetCY, outerColor);

UI/window-projector.hpp

@@ -40,12 +40,17 @@ private:
 	ProjectorType type = ProjectorType::Source;
 	OBSWeakSource multiviewScenes[8];
 	OBSSource     multiviewLabels[10];
-	gs_vertbuffer_t *innerBox = nullptr;
-	gs_vertbuffer_t *leftVLine = nullptr;
-	gs_vertbuffer_t *rightVLine = nullptr;
-	gs_vertbuffer_t *leftLine = nullptr;
-	gs_vertbuffer_t *topLine = nullptr;
-	gs_vertbuffer_t *rightLine = nullptr;
+	gs_vertbuffer_t *actionSafeMargin      = nullptr;
+	gs_vertbuffer_t *graphicsSafeMargin    = nullptr;
+	gs_vertbuffer_t *fourByThreeSafeMargin = nullptr;
+	gs_vertbuffer_t *leftLine              = nullptr;
+	gs_vertbuffer_t *topLine               = nullptr;
+	gs_vertbuffer_t *rightLine             = nullptr;
+	float lineLength                = 0.1f;
+	// Rec. ITU-R BT.1848-1 / EBU R 95
+	float actionSafePercentage      = 0.035f; // 3.5%
+	float graphicsSafePercentage    = 0.05f; // 5.0%
+	float fourByThreeSafePercentage = 0.1625f; // 16.25%
 	bool ready = false;
 
 	// argb colors