Issue when trying to query for component

[Oreboat]

I want to preface this by saying that I am new to using this library, but I'm trying to query for a camera component and I get the following errors when trying to run the system
goroutine 1 [running, locked to thread]:

github.com/mlange-42/arche/ecs.(*Query).nextNode(0xc00002fa80)
        C:/Users/{name}/go/pkg/mod/github.com/mlange-42/[email protected]/ecs/query.go:306 +0x2cf
github.com/mlange-42/arche/ecs.(*Query).nextNodeOrArchetype(0xc00002f998?)
        C:/Users/{name}/go/pkg/mod/github.com/mlange-42/[email protected]/ecs/query.go:299 +0x2e
github.com/mlange-42/arche/ecs.(*Query).nextArchetype(0xa00000000?)
        C:/Users/{name}/go/pkg/mod/github.com/mlange-42/[email protected]/ecs/query.go:229 +0x2a
github.com/mlange-42/arche/ecs.(*Query).Next(...)
        C:/Users/{name}/go/pkg/mod/github.com/mlange-42/[email protected]/ecs/query.go:90
FeralSoul/pkg/client/renderer.RenderLoop(0xc00000c408)
        C:/Users/{name}/OneDrive/Desktop/Feral-Soul/Feral-Soul/pkg/client/renderer/renderer.go:39 +0x2b0
FeralSoul/pkg/client.Init()
        C:/Users/{name}/OneDrive/Desktop/Feral-Soul/Feral-Soul/pkg/client/client.go:19 +0x133
main.main()
        C:/Users/{name}/OneDrive/Desktop/Feral-Soul/Feral-Soul/main.go:11 +0xf

my code is

package renderer

import (
	components "FeralSoul/pkg/components/client"

	rl "github.com/gen2brain/raylib-go/raylib"
	"github.com/mlange-42/arche/ecs"
	"github.com/mlange-42/arche/generic"
)

// Initialize implements model.System.
func InitCamera(world *ecs.World) {
	mapper := generic.NewMap1[components.Camera](world)

	camEntity := mapper.New()

	camera := mapper.Get(camEntity)

	camera.Cam = rl.Camera3D{
		Position: rl.NewVector3(0, 10, 10),
		Target:   rl.NewVector3(0, 0, 0),
		Up:       rl.NewVector3(0, 1, 0),
		Fovy:     45,
	}
}

// Update implements model.System.
func RenderLoop(world *ecs.World) {
	filter := generic.NewFilter1[components.Camera]()

	query := filter.Query(world)

	for !rl.WindowShouldClose() {
		rl.BeginDrawing()
		if query.Count() == 0 {
			rl.EndDrawing()
			return // No entities to process
		}
		for query.Next() {
			camera := query.Get()
			rl.BeginMode3D(camera.Cam)
			rl.ClearBackground(rl.White)
			rl.DrawCube(rl.NewVector3(0, 0, 0), 1, 1, 1, rl.SkyBlue)
			rl.DrawCubeWires(rl.NewVector3(0, 0, 0), 1, 1, 1, rl.Blue)
			rl.DrawGrid(10, 1)

			rl.EndMode3D()
		}

		rl.DrawFPS(10, 10)
		rl.EndDrawing()
	}

}

package components

import (
	rl "github.com/gen2brain/raylib-go/raylib"
)

type Camera = struct {
	Cam rl.Camera3D
}

what am I doing wrong, thank you in advance

[Oreboat]

Nevermind it was the result of query being nested in the window loop, I made my own code that added in proper systems and ran that and it worked

[mlange-42]

Good to read that you could solve it yourself. Not sure what the problem was.

As an aside: Performance-wise, you will not have any savings by counting the query and checking for zero. Counting takes time similar to iterating an empty query. Better use a bool variable that you set to true in the loop.

EDIT: of course, counting a query with many entities takes less time than iterating them. But counting a query with many archetypes takes more time than iterating an empty query.

Further, it you don't iterate the query, you need to Close() it. Otherwise, your world stays locked and you will eventually run out of lock bits.

[Oreboat]

thanks for the feedback, I've adjusted my code to not check if it's empty and then to close the query when this call of the render loop finished up

[mlange-42]

If you don't do the count and about, but iterate the query, you don't need to close it.