Rendering now works! Added shaders for reference.

sprite.go

@@ -0,0 +1,163 @@
+package goga
+
+import (
+	"github.com/go-gl/gl/v4.5-core/gl"
+)
+
+const (
+	sprite_renderer_name = "spriteRenderer"
+)
+
+// Sprite is an actor having a 2D position and a texture.
+type Sprite struct {
+	*Actor
+	*Pos2D
+	*Tex
+}
+
+// The sprite renderer is a system rendering sprites.
+// It has a 2D position componente, to move all sprites at once.
+type SpriteRenderer struct {
+	Pos2D
+
+	Shader *Shader
+	Camera *Camera
+
+	sprites                 []Sprite
+	index, vertex, texCoord *VBO
+	vao                     *VAO
+}
+
+// Creates a new sprite with given texture.
+func NewSprite(tex *Tex) *Sprite {
+	sprite := &Sprite{}
+	sprite.Actor = NewActor()
+	sprite.Pos2D = NewPos2D()
+	sprite.Tex = tex
+	sprite.Size = Vec2{tex.GetSize().X, tex.GetSize().Y}
+	sprite.Scale = Vec2{1, 1}
+	sprite.Visible = true
+
+	CheckGLError()
+
+	return sprite
+}
+
+// Creates a new sprite renderer using given shader and camera.
+// If shader and/or camera are nil, the default one will be used.
+func NewSpriteRenderer(shader *Shader, camera *Camera, flip bool) *SpriteRenderer {
+	if shader == nil {
+		shader = Default2DShader
+	}
+
+	if camera == nil {
+		camera = DefaultCamera
+	}
+
+	renderer := &SpriteRenderer{}
+	renderer.Shader = shader
+	renderer.Camera = camera
+	renderer.sprites = make([]Sprite, 0)
+	renderer.index, renderer.vertex, renderer.texCoord = CreateRectMesh(flip)
+	renderer.Size = Vec2{1, 1}
+	renderer.Scale = Vec2{1, 1}
+
+	renderer.vao = NewVAO()
+	renderer.vao.Bind()
+	renderer.Shader.EnableVertexAttribArrays()
+	renderer.index.Bind()
+	renderer.vertex.Bind()
+	renderer.vertex.AttribPointer(shader.GetAttribLocation(Default_shader_2D_vertex_attrib), 2, gl.FLOAT, false, 0)
+	renderer.texCoord.Bind()
+	renderer.texCoord.AttribPointer(shader.GetAttribLocation(Default_shader_2D_texcoord_attrib), 2, gl.FLOAT, false, 0)
+	renderer.vao.Unbind()
+
+	CheckGLError()
+
+	return renderer
+}
+
+// Frees recources created by sprite renderer.
+// This is called automatically when system gets removed.
+func (s *SpriteRenderer) Cleanup() {
+	s.index.Drop()
+	s.vertex.Drop()
+	s.texCoord.Drop()
+	s.vao.Drop()
+}
+
+// Adds sprite to the renderer.
+func (s *SpriteRenderer) Add(actor interface{}) bool {
+	sprite, ok := actor.(*Sprite)
+
+	if !ok {
+		return false
+	}
+
+	s.sprites = append(s.sprites, *sprite)
+
+	return true
+}
+
+// Removes sprite from renderer.
+func (s *SpriteRenderer) Remove(actor interface{}) bool {
+	sprite, ok := actor.(Sprite)
+
+	if !ok {
+		return false
+	}
+
+	for i, sp := range s.sprites {
+		if sp == sprite {
+			s.sprites = append(s.sprites[:i], s.sprites[i+1:]...)
+			return true
+		}
+	}
+
+	return false
+}
+
+// Removes sprite from renderer by ID.
+func (s *SpriteRenderer) RemoveById(id ActorId) bool {
+	for i, sprite := range s.sprites {
+		if sprite.Actor.GetId() == id {
+			s.sprites = append(s.sprites[:i], s.sprites[i+1:]...)
+			return true
+		}
+	}
+
+	return false
+}
+
+// Removes all sprites from renderer.
+func (s *SpriteRenderer) RemoveAll() {
+	s.sprites = make([]Sprite, 0)
+}
+
+// Returns number of sprites.
+func (s *SpriteRenderer) Len() int {
+	return len(s.sprites)
+}
+
+func (s *SpriteRenderer) GetName() string {
+	return sprite_renderer_name
+}
+
+// Renders sprites.
+func (s *SpriteRenderer) Update(delta float64) {
+	s.Shader.Bind()
+	s.Shader.SendMat3(Default_shader_2D_ortho, *MultMat3(s.Camera.CalcOrtho(), s.CalcModel()))
+	s.Shader.SendUniform1i(Default_shader_2D_tex, 0)
+	s.vao.Bind()
+
+	for i := range s.sprites {
+		if !s.sprites[i].Visible {
+			continue
+		}
+
+		s.Shader.SendMat3(Default_shader_2D_model, *s.sprites[i].CalcModel())
+		s.sprites[i].Tex.Bind()
+
+		gl.DrawElements(gl.TRIANGLES, 6, gl.UNSIGNED_INT, nil)
+	}
+}