Depth-sort decals properly, add decal offset, and fix painting cursor position

src/game/components/tool-component.hpp

@@ -28,6 +28,7 @@ struct tool_component
 	float idle_distance;
 	float active_distance;
 	bool heliotropic;
+	float3 cursor;
 	
 	//float activation_speed;
 };

src/game/events/tool-events.cpp

@@ -23,6 +23,7 @@ event_base* tool_pressed_event::clone() const
 {
 	tool_pressed_event* event = new tool_pressed_event();
 	event->entity = entity;
+	event->position = position;
 	return event;
 }
 
@@ -30,5 +31,6 @@ event_base* tool_released_event::clone() const
 {
 	tool_released_event* event = new tool_released_event();
 	event->entity = entity;
+	event->position = position;
 	return event;
 }

src/game/events/tool-events.hpp

@@ -21,6 +21,7 @@
 #define ANTKEEPER_TOOL_EVENTS_HPP
 
 #include "event/event.hpp"
+#include "utility/fundamental-types.hpp"
 #include <entt/entt.hpp>
 
 class tool_pressed_event: public event<tool_pressed_event>
@@ -28,6 +29,7 @@ class tool_pressed_event: public event
 public:
 	virtual event_base* clone() const;
 	entt::entity entity;
+	float3 position;
 };
 
 class tool_released_event: public event<tool_released_event>
@@ -35,6 +37,7 @@ class tool_released_event: public event
 public:
 	virtual event_base* clone() const;
 	entt::entity entity;
+	float3 position;
 };
 
 #endif // ANTKEEPER_TOOL_EVENTS_HPP

src/game/systems/painting-system.cpp

@@ -20,6 +20,7 @@
 #include "painting-system.hpp"
 #include "game/components/transform-component.hpp"
 #include "game/components/brush-component.hpp"
+#include "game/components/tool-component.hpp"
 #include "event/event-dispatcher.hpp"
 #include "resources/resource-manager.hpp"
 #include "scene/scene.hpp"
@@ -49,6 +50,7 @@ painting_system::painting_system(entt::registry& registry, ::event_dispatcher* e
 	event_dispatcher->subscribe<tool_released_event>(this);
 	
 	max_miter_angle = math::radians(135.0f);
+	decal_offset = 0.01f;
 	stroke_width = 1.0f;
 	min_stroke_length = 1.0f;
 	min_stroke_length_squared = min_stroke_length * min_stroke_length;
@@ -93,7 +95,9 @@ void painting_system::update(double t, double dt)
 {
 	if (painting)
 	{
-		auto cast_result = cast_ray(ec::get_world_transform(registry, brush_entity).translation);
+		const tool_component& tool = registry.get<tool_component>(brush_entity);
+		
+		auto cast_result = cast_ray(tool.cursor);
 		if (cast_result.has_value())
 		{
 			float3 p2 = 
@@ -123,10 +127,10 @@ void painting_system::update(double t, double dt)
 				
 				float3 a = p0a;
 				float3 b = p0b;
-				float3 c = p1 - segment_right * stroke_width * 0.5f;
-				float3 d = p1 + segment_right * stroke_width * 0.5f;
-				float3 e = p2 - segment_right * stroke_width * 0.5f;
-				float3 f = p2 + segment_right * stroke_width * 0.5f;
+				float3 c = p1 - segment_right * stroke_width * 0.5f + segment_up * decal_offset;
+				float3 d = p1 + segment_right * stroke_width * 0.5f + segment_up * decal_offset;
+				float3 e = p2 - segment_right * stroke_width * 0.5f + segment_up * decal_offset;
+				float3 f = p2 + segment_right * stroke_width * 0.5f + segment_up * decal_offset;
 				
 				// Adjust c and d
 				bool mitered = false;
@@ -136,8 +140,8 @@ void painting_system::update(double t, double dt)
 					if (angle < max_miter_angle)
 					{
 						mitered = true;
-						c = p1 - float3{miter.x, 0.0f, miter.y} * miter_length * 0.5f;
-						d = p1 + float3{miter.x, 0.0f, miter.y} * miter_length * 0.5f;
+						c = p1 - float3{miter.x, 0.0f, miter.y} * miter_length * 0.5f + segment_up * decal_offset;
+						d = p1 + float3{miter.x, 0.0f, miter.y} * miter_length * 0.5f + segment_up * decal_offset;
 					}
 				}
 				
@@ -201,7 +205,7 @@ void painting_system::handle_event(const tool_pressed_event& event)
 {
 	if (registry.has<brush_component>(event.entity))
 	{
-		auto cast_result = cast_ray(ec::get_world_transform(registry, event.entity).translation);
+		auto cast_result = cast_ray(event.position);
 		
 		if (cast_result.has_value())
 		{

src/game/systems/painting-system.hpp

@@ -67,6 +67,7 @@ private:
 	int max_stroke_segments;
 	int current_stroke_segment;
 	float max_miter_angle;
+	float decal_offset;
 	float3 stroke_bounds_min;
 	float3 stroke_bounds_max;
 	float3 p0;

src/game/systems/tool-system.cpp

@@ -208,6 +208,9 @@ void tool_system::update(double t, double dt)
 				ec::assign_render_layers(registry, active_tool, 1);
 				warp = false;
 			}
+			
+			// Update tool's cursor position
+			tool.cursor = pick_spring.x0;
 
 			//math::quaternion<float> rotation = math::angle_axis(orbit_cam->get_azimuth() + pick_angle, float3{0, 1, 0});
 			//transform.transform.rotation = rotation;
@@ -296,6 +299,7 @@ void tool_system::set_tool_active(bool active)
 		// Queue tool pressed event
 		tool_pressed_event event;
 		event.entity = active_tool;
+		event.position = pick_spring.x0;
 		event_dispatcher->queue(event);
 	}
 	else
@@ -306,6 +310,7 @@ void tool_system::set_tool_active(bool active)
 			// Queue tool pressed event
 		tool_released_event event;
 		event.entity = active_tool;
+		event.position = pick_spring.x0;
 		event_dispatcher->queue(event);
 	}
 }

src/renderer/passes/material-pass.cpp

@@ -347,14 +347,22 @@ void material_pass::render(render_context* context) const
 				{
 					if (material_flags & MATERIAL_FLAG_DECAL)
 					{
-						glDisable(GL_DEPTH_TEST);
+						glEnable(GL_DEPTH_TEST);
+						glDepthFunc(GL_LEQUAL);
+						glDepthMask(GL_FALSE);
+						
 						glEnable(GL_STENCIL_TEST);
 						glStencilFunc(GL_EQUAL, 1, ~0);
+						//glStencilOp(GL_KEEP, GL_KEEP, GL_ZERO);
+						//glStencilMask(~0);
+						glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
 						glStencilMask(0);
 					}
 					else
 					{
 						glEnable(GL_DEPTH_TEST);
+						glDepthFunc(GL_LESS);
+						glDepthMask(GL_TRUE);
 						glDisable(GL_STENCIL_TEST);
 						glStencilMask(0);
 					}
@@ -582,8 +590,36 @@ bool operation_compare(const render_operation& a, const render_operation& b)
 			{
 				if (transparent_b)
 				{
-					// A and B are both transparent, render back to front
-					return (a.depth >= b.depth);
+					// Determine decal status
+					bool decal_a = a.material->get_flags() & MATERIAL_FLAG_DECAL;
+					bool decal_b = b.material->get_flags() & MATERIAL_FLAG_DECAL;
+					
+					if (decal_a)
+					{
+						if (decal_b)
+						{
+							// A and B are both transparent decals, render back to front
+							return (a.depth >= b.depth);
+						}
+						else
+						{
+							// A is a transparent decal, B is transparent but not a decal, render A first
+							return true;
+						}
+					}
+					else
+					{
+						if (decal_b)
+						{
+							// A is transparent but not a decal, B is a transparent decal, render B first
+							return false;
+						}
+						else
+						{
+							// A and B are both transparent, but not decals, render back to front
+							return (a.depth >= b.depth);
+						}
+					}
 				}
 				else
 				{