From 139e668233eb0600d64a874b579c103478ed0574 Mon Sep 17 00:00:00 2001
From: Marvin Blum <marvin@marvinblum.de>
Date: Sat, 7 May 2016 20:26:36 +0200
Subject: [PATCH] Removed shader, added 3D rendering (no demo yet, coming
 next), started bitmap font rendering, a few fixes and improvements.

---
 README.md                  |   8 +
 demo/model/assets/cube.ply |  53 +++++
 demo/model/assets/cube.png | Bin 0 -> 5810 bytes
 game.go                    | 117 +++++++++--
 loader.go                  |  19 ++
 model.go                   | 193 ++++++++++++++++++
 res_util.go                |  18 ++
 shader/basic2D.fs          |  12 --
 shader/basic2D.vs          |  13 --
 shader/basic3D.fs          |  12 --
 shader/basic3D.vs          |  13 --
 shader/text.fs             |  13 --
 shader/text.vs             |  13 --
 sprite.go                  |  29 +--
 text.go                    | 402 +++++++++++++++++++++++++++++++++++++
 15 files changed, 809 insertions(+), 106 deletions(-)
 create mode 100644 demo/model/assets/cube.ply
 create mode 100644 demo/model/assets/cube.png
 create mode 100644 model.go
 delete mode 100644 shader/basic2D.fs
 delete mode 100644 shader/basic2D.vs
 delete mode 100644 shader/basic3D.fs
 delete mode 100644 shader/basic3D.vs
 delete mode 100644 shader/text.fs
 delete mode 100644 shader/text.vs
 create mode 100644 text.go

diff --git a/README.md b/README.md
index 9132c1c..c5e4d4f 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,11 @@ Game engine written in Go using OpenGL and GLFW. Mostly for 2D rendering, but al
 
 ## Install
 
+go-game requires OpenGL and GLFW. The following three steps install everything you need:
+
 ```
+go get github.com/go-gl/gl/v4.5-core/gl
+go get github.com/go-gl/glfw/v3.1/glfw
 go get github.com/DeKugelschieber/go-game
 ```
 
@@ -23,3 +27,7 @@ You can find some examples within the demo folder. For full reference visit: htt
     - 3.1
 
 To use an older GL version, you need to replace the GL imports in package goga. It should mostly be compatible down to 3.x.
+
+## License
+
+MIT
diff --git a/demo/model/assets/cube.ply b/demo/model/assets/cube.ply
new file mode 100644
index 0000000..fda7427
--- /dev/null
+++ b/demo/model/assets/cube.ply
@@ -0,0 +1,53 @@
+ply
+format ascii 1.0
+comment Created by Blender 2.69 (sub 0) - www.blender.org, source file: ''
+element vertex 26
+property float x
+property float y
+property float z
+property float nx
+property float ny
+property float nz
+property float s
+property float t
+element face 12
+property list uchar uint vertex_indices
+end_header
+1.000000 1.000000 -1.000000 0.000000 0.000000 -1.000000 0.499999 0.500000
+1.000000 -1.000000 -1.000000 0.000000 0.000000 -1.000000 0.499999 0.749956
+-1.000000 -1.000000 -1.000000 0.000000 0.000000 -1.000000 0.250043 0.749957
+1.000000 0.999999 1.000000 -0.000000 -0.000000 1.000000 0.499998 0.250043
+-1.000000 1.000000 1.000000 -0.000000 -0.000000 1.000000 0.250041 0.250044
+0.999999 -1.000001 1.000000 -0.000000 -0.000000 1.000000 0.499996 0.000087
+1.000000 1.000000 -1.000000 1.000000 0.000000 -0.000000 0.749956 0.749956
+1.000000 0.999999 1.000000 1.000000 0.000000 -0.000000 0.749956 0.999913
+1.000000 -1.000000 -1.000000 1.000000 0.000000 -0.000000 0.499999 0.749956
+1.000000 -1.000000 -1.000000 -0.000000 -1.000000 -0.000000 0.499999 0.749956
+0.999999 -1.000001 1.000000 -0.000000 -1.000000 -0.000000 0.500000 0.999913
+-1.000000 -1.000000 -1.000000 -0.000000 -1.000000 -0.000000 0.250043 0.749957
+-1.000000 -1.000000 -1.000000 -1.000000 0.000000 -0.000000 0.250043 0.749957
+-1.000000 -1.000000 1.000000 -1.000000 0.000000 -0.000000 0.250043 0.999913
+-1.000000 1.000000 1.000000 -1.000000 0.000000 -0.000000 0.000087 0.999913
+1.000000 0.999999 1.000000 0.000000 1.000000 0.000000 0.499998 0.250043
+1.000000 1.000000 -1.000000 0.000000 1.000000 0.000000 0.499999 0.500000
+-1.000000 1.000000 1.000000 0.000000 1.000000 0.000000 0.250041 0.250044
+-1.000000 1.000000 -1.000000 0.000000 0.000000 -1.000000 0.250042 0.500001
+1.000000 0.999999 1.000000 1.000000 -0.000001 0.000000 0.749956 0.999913
+0.999999 -1.000001 1.000000 1.000000 -0.000001 0.000000 0.500000 0.999913
+1.000000 -1.000000 -1.000000 1.000000 -0.000001 0.000000 0.499999 0.749956
+-1.000000 1.000000 -1.000000 0.000000 1.000000 0.000000 0.250042 0.500001
+-1.000000 -1.000000 1.000000 0.000000 -0.000000 1.000000 0.250040 0.000088
+-1.000000 1.000000 -1.000000 -1.000000 0.000000 -0.000000 0.000087 0.749957
+-1.000000 -1.000000 1.000000 -0.000000 -1.000000 0.000000 0.250043 0.999913
+3 0 1 2
+3 3 4 5
+3 6 7 8
+3 9 10 11
+3 12 13 14
+3 15 16 17
+3 18 0 2
+3 19 20 21
+3 16 22 17
+3 4 23 5
+3 24 12 14
+3 10 25 11
diff --git a/demo/model/assets/cube.png b/demo/model/assets/cube.png
new file mode 100644
index 0000000000000000000000000000000000000000..530cdd44c98edba3adbe2a89294347bb010a6fff
GIT binary patch
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literal 0
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diff --git a/game.go b/game.go
index 4eb608f..fff4588 100644
--- a/game.go
+++ b/game.go
@@ -22,14 +22,15 @@ const (
 	Default_shader_2D_model           = "m"
 	Default_shader_2D_tex             = "tex"
 
+	// source for 2D shader
 	default_shader_2d_vertex_src = `#version 130
 		uniform mat3 o, m;
 		in vec2 vertex;
 		in vec2 texCoord;
 		out vec2 tc;
 		void main(){
-		tc = texCoord;
-		gl_Position = vec4(o*m*vec3(vertex, 1.0), 1.0);
+			tc = texCoord;
+			gl_Position = vec4(o*m*vec3(vertex, 1.0), 1.0);
 		}`
 	default_shader_2d_fragment_src = `#version 130
 		precision highp float;
@@ -37,7 +38,61 @@ const (
 		in vec2 tc;
 		out vec4 color;
 		void main(){
-		color = texture(tex, tc);
+			color = texture(tex, tc);
+		}`
+
+	// constants for default 3D shader
+	Default_shader_3D_vertex_attrib   = "vertex"
+	Default_shader_3D_texcoord_attrib = "texCoord"
+	Default_shader_3D_pv              = "pv"
+	Default_shader_3D_model           = "m"
+	Default_shader_3D_tex             = "tex"
+
+	// source for 3D shader
+	default_shader_3d_vertex_src = `#version 130
+		uniform mat4 pv, m;
+		in vec3 vertex;
+		in vec2 texCoord;
+		out vec2 tc;
+		void main(){
+			tc = texCoord;
+			gl_Position = pv*m*vec4(vertex, 1.0);
+		}`
+	default_shader_3d_fragment_src = `#version 130
+		precision highp float;
+		uniform sampler2D tex;
+		in vec2 tc;
+		out vec4 color;
+		void main(){
+			color = texture(tex, tc);
+		}`
+
+	// constants for default text shader
+	Default_shader_text_vertex_attrib   = "vertex"
+	Default_shader_text_texcoord_attrib = "texCoord"
+	Default_shader_text_ortho           = "o"
+	Default_shader_text_model           = "m"
+	Default_shader_text_tex             = "tex"
+	Default_shader_text_color           = "color"
+
+	// source for text shader
+	default_shader_text_vertex_src = `#version 130
+		uniform mat3 o, m;
+		in vec2 vertex;
+		in vec2 texCoord;
+		out vec2 tc;
+		void main(){
+			tc = texCoord;
+			gl_Position = vec4(o*m*vec3(vertex, 1.0), 1.0);
+		}`
+	default_shader_text_fragment_src = `#version 130
+		precision highp float;
+		uniform sampler2D tex;
+		uniform vec4 color;
+		in vec2 tc;
+		out vec4 c;
+		void main(){
+			c = texture(tex, tc)*color;
 		}`
 )
 
@@ -73,8 +128,10 @@ var (
 	viewportHeight int
 
 	// Default resources
-	DefaultCamera   *Camera
-	Default2DShader *Shader
+	DefaultCamera     *Camera
+	Default2DShader   *Shader
+	Default3DShader   *Shader
+	DefaultTextShader *Shader
 )
 
 func init() {
@@ -211,7 +268,7 @@ func initGoga(width, height int) {
 	DefaultCamera.CalcRatio()
 	DefaultCamera.CalcOrtho()
 
-	// default shader
+	// default 2D shader
 	shader, err := NewShader(default_shader_2d_vertex_src, default_shader_2d_fragment_src)
 
 	if err != nil {
@@ -222,25 +279,52 @@ func initGoga(width, height int) {
 	Default2DShader.BindAttrib(Default_shader_2D_vertex_attrib)
 	Default2DShader.BindAttrib(Default_shader_2D_texcoord_attrib)
 
+	// default 3D shader
+	shader, err = NewShader(default_shader_3d_vertex_src, default_shader_3d_fragment_src)
+
+	if err != nil {
+		panic(err)
+	}
+
+	Default3DShader = shader
+	Default3DShader.BindAttrib(Default_shader_3D_vertex_attrib)
+	Default3DShader.BindAttrib(Default_shader_3D_texcoord_attrib)
+
+	// default text shader
+	shader, err = NewShader(default_shader_text_vertex_src, default_shader_text_fragment_src)
+
+	if err != nil {
+		panic(err)
+	}
+
+	DefaultTextShader = shader
+	DefaultTextShader.BindAttrib(Default_shader_text_vertex_attrib)
+	DefaultTextShader.BindAttrib(Default_shader_text_texcoord_attrib)
+
 	// settings and registration
 	ClearColorBuffer(true)
 	EnableAlphaBlending(true)
 	AddLoader(&PngLoader{gl.LINEAR, false})
 	AddLoader(&PlyLoader{gl.STATIC_DRAW})
 	AddSystem(NewSpriteRenderer(nil, nil, false))
+	AddSystem(NewModelRenderer(nil, nil, false))
 	AddSystem(NewCulling2D(0, 0, width, height))
 }
 
 func cleanup() {
 	// cleanup resources
-	log.Printf("Cleaning up %v resources", len(resources))
+	log.Printf("Trying to cleaning up %v resources", len(resources))
+	dropped := 0
 
 	for _, res := range resources {
 		if drop, ok := res.(Dropable); ok {
 			drop.Drop()
+			dropped++
 		}
 	}
 
+	log.Printf("Dropped %v resources", dropped)
+
 	// cleanup systems
 	log.Printf("Cleaning up %v systems", len(systems))
 
@@ -259,6 +343,7 @@ func cleanup() {
 	log.Print("Cleaning up default resources")
 
 	Default2DShader.Drop()
+	DefaultTextShader.Drop()
 }
 
 // Stops the game and closes the window.
@@ -287,6 +372,15 @@ func ClearDepthBuffer(do bool) {
 	}
 }
 
+func removeClearBuffer(buffer uint32) {
+	for i, b := range clearBuffer {
+		if b == buffer {
+			clearBuffer = append(clearBuffer[:i], clearBuffer[i+1:]...)
+			return
+		}
+	}
+}
+
 // Enables/Disables alpha blending by source alpha channel.
 // BLEND = SRC_ALPHA | ONE_MINUS_SRC_ALPHA
 func EnableAlphaBlending(enable bool) {
@@ -332,12 +426,3 @@ func GetWidth() int {
 func GetHeight() int {
 	return viewportHeight
 }
-
-func removeClearBuffer(buffer uint32) {
-	for i, buffer := range clearBuffer {
-		if buffer == buffer {
-			clearBuffer = append(clearBuffer[:i], clearBuffer[i+1:]...)
-			return
-		}
-	}
-}
diff --git a/loader.go b/loader.go
index ebd602e..835acb8 100644
--- a/loader.go
+++ b/loader.go
@@ -75,6 +75,25 @@ type Ply struct {
 	IndexBuffer, VertexBuffer, TexCoordBuffer, NormalBuffer *VBO
 }
 
+// Drops contained GL buffers.
+func (p *Ply) Drop() {
+	if p.IndexBuffer != nil {
+		p.IndexBuffer.Drop()
+	}
+
+	if p.VertexBuffer != nil {
+		p.VertexBuffer.Drop()
+	}
+
+	if p.TexCoordBuffer != nil {
+		p.TexCoordBuffer.Drop()
+	}
+
+	if p.NormalBuffer != nil {
+		p.NormalBuffer.Drop()
+	}
+}
+
 // Returns the name of this resource.
 func (p *Ply) GetName() string {
 	return p.name
diff --git a/model.go b/model.go
new file mode 100644
index 0000000..a66324d
--- /dev/null
+++ b/model.go
@@ -0,0 +1,193 @@
+package goga
+
+import (
+	"github.com/go-gl/gl/v4.5-core/gl"
+)
+
+const (
+	model_renderer_name = "modelRenderer"
+)
+
+// Component representing a 3D mesh.
+type Mesh struct {
+	Index, Vertex, TexCoord *VBO
+	Vao                     *VAO
+}
+
+// Creates a new mesh with given GL buffers.
+// The VAO must be prepared by ModelRenderer.
+func NewMesh(index, vertex, texcoord *VBO) *Mesh {
+	mesh := &Mesh{}
+	mesh.Index = index
+	mesh.Vertex = vertex
+	mesh.TexCoord = texcoord
+
+	CheckGLError()
+
+	return mesh
+}
+
+// Drops the VBOs and VAO contained in mesh.
+// This must not be done, if mesh was filled from outer source (like a ply file).
+func (m *Mesh) Drop() {
+	m.Index.Drop()
+	m.Vertex.Drop()
+	m.TexCoord.Drop()
+	m.Vao.Drop()
+}
+
+// Model is an actor having a 3D position, a texture and a 3D mesh.
+type Model struct {
+	*Actor
+	*Pos3D
+	*Tex
+	*Mesh
+}
+
+// Creates a new model with given mesh and texture.
+func NewModel(mesh *Mesh, tex *Tex) *Model {
+	model := &Model{}
+	model.Actor = NewActor()
+	model.Pos3D = NewPos3D()
+	model.Tex = tex
+	model.Mesh = mesh
+	model.Size = Vec3{1, 1, 1}
+	model.Scale = Vec3{1, 1, 1}
+	model.Visible = true
+
+	CheckGLError()
+
+	return model
+}
+
+// The model renderer is a system rendering models.
+// It has a 3D position component, to move all models at once.
+type ModelRenderer struct {
+	Pos3D
+
+	Shader *Shader
+	Camera *Camera
+	ortho  bool
+
+	models []Model
+}
+
+// Creates a new model renderer using given shader and camera.
+// If shader and/or camera are nil, the default one will be used.
+// Orth can be set to true, to use orthogonal projection.
+func NewModelRenderer(shader *Shader, camera *Camera, ortho bool) *ModelRenderer {
+	if shader == nil {
+		shader = Default3DShader
+	}
+
+	if camera == nil {
+		camera = DefaultCamera
+	}
+
+	renderer := &ModelRenderer{}
+	renderer.Shader = shader
+	renderer.Camera = camera
+	renderer.ortho = ortho
+	renderer.models = make([]Model, 0)
+	renderer.Size = Vec3{1, 1, 1}
+	renderer.Scale = Vec3{1, 1, 1}
+
+	CheckGLError()
+
+	return renderer
+}
+
+func (s *ModelRenderer) Cleanup() {}
+
+// Prepares a model to be rendered by setting up its VAO.
+func (s *ModelRenderer) Prepare(model *Model) {
+	model.Vao = NewVAO()
+	model.Vao.Bind()
+	s.Shader.EnableVertexAttribArrays()
+	model.Index.Bind()
+	model.Vertex.Bind()
+	model.Vertex.AttribPointer(s.Shader.GetAttribLocation(Default_shader_3D_vertex_attrib), 3, gl.FLOAT, false, 0)
+	model.TexCoord.Bind()
+	model.TexCoord.AttribPointer(s.Shader.GetAttribLocation(Default_shader_3D_texcoord_attrib), 2, gl.FLOAT, false, 0)
+	model.Vao.Unbind()
+}
+
+// Adds model to the renderer.
+// Perpare it first!
+func (s *ModelRenderer) Add(actor *Actor, pos *Pos3D, tex *Tex, mesh *Mesh) bool {
+	id := actor.GetId()
+
+	for _, model := range s.models {
+		if id == model.Actor.GetId() {
+			return false
+		}
+	}
+
+	s.models = append(s.models, Model{actor, pos, tex, mesh})
+
+	return true
+}
+
+// Removes model from renderer.
+func (s *ModelRenderer) Remove(actor *Actor) bool {
+	return s.RemoveById(actor.GetId())
+}
+
+// Removes model from renderer by ID.
+func (s *ModelRenderer) RemoveById(id ActorId) bool {
+	for i, model := range s.models {
+		if model.Actor.GetId() == id {
+			s.models = append(s.models[:i], s.models[i+1:]...)
+			return true
+		}
+	}
+
+	return false
+}
+
+// Removes all sprites.
+func (s *ModelRenderer) RemoveAll() {
+	s.models = make([]Model, 0)
+}
+
+// Returns number of sprites.
+func (s *ModelRenderer) Len() int {
+	return len(s.models)
+}
+
+func (s *ModelRenderer) GetName() string {
+	return model_renderer_name
+}
+
+// Render models.
+func (s *ModelRenderer) Update(delta float64) {
+	s.Shader.Bind()
+	s.Shader.SendUniform1i(Default_shader_3D_tex, 0)
+
+	if s.ortho {
+		s.Shader.SendMat4(Default_shader_3D_pv, *MultMat4(s.Camera.CalcOrtho3D(), s.CalcModel()))
+	} else {
+		pv := s.Camera.CalcProjection()
+		pv.Mult(s.Camera.CalcView())
+		s.Shader.SendMat4(Default_shader_3D_pv, *pv)
+	}
+
+	var tid uint32
+
+	for i := range s.models {
+		if !s.models[i].Visible {
+			continue
+		}
+
+		s.Shader.SendMat4(Default_shader_3D_model, *s.models[i].CalcModel())
+		s.models[i].Vao.Bind()
+
+		// prevent texture switching when not neccessary
+		if tid != s.models[i].Tex.GetId() {
+			tid = s.models[i].Tex.GetId()
+			s.models[i].Tex.Bind()
+		}
+
+		gl.DrawElements(gl.TRIANGLES, s.models[i].Index.Size(), gl.UNSIGNED_INT, nil)
+	}
+}
diff --git a/res_util.go b/res_util.go
index d4dd0e6..26a0b8b 100644
--- a/res_util.go
+++ b/res_util.go
@@ -21,3 +21,21 @@ func GetTex(name string) (*Tex, error) {
 
 	return tex, nil
 }
+
+// Finds and returns a Ply resource.
+// If not found or when the resource is of wrong type, an error will be returned.
+func GetPly(name string) (*Ply, error) {
+	res := GetResByName(name)
+
+	if res == nil {
+		return nil, errors.New("Resource not found")
+	}
+
+	ply, ok := res.(*Ply)
+
+	if !ok {
+		return nil, errors.New("Resource was not of type *Ply")
+	}
+
+	return ply, nil
+}
diff --git a/shader/basic2D.fs b/shader/basic2D.fs
deleted file mode 100644
index 71bd6c0..0000000
--- a/shader/basic2D.fs
+++ /dev/null
@@ -1,12 +0,0 @@
-#version 130
-precision highp float;
-
-uniform sampler2D tex;
-
-in vec2 tc;
-
-out vec4 color;
-
-void main(){
-	color = texture(tex, tc);
-}
diff --git a/shader/basic2D.vs b/shader/basic2D.vs
deleted file mode 100644
index 1076653..0000000
--- a/shader/basic2D.vs
+++ /dev/null
@@ -1,13 +0,0 @@
-#version 130
-
-uniform mat3 o, m;
-
-in vec2 vertex;
-in vec2 texCoord;
-
-out vec2 tc;
-
-void main(){
-	tc = texCoord;
-	gl_Position = vec4(o*m*vec3(vertex, 1.0), 1.0);
-}
diff --git a/shader/basic3D.fs b/shader/basic3D.fs
deleted file mode 100644
index 71bd6c0..0000000
--- a/shader/basic3D.fs
+++ /dev/null
@@ -1,12 +0,0 @@
-#version 130
-precision highp float;
-
-uniform sampler2D tex;
-
-in vec2 tc;
-
-out vec4 color;
-
-void main(){
-	color = texture(tex, tc);
-}
diff --git a/shader/basic3D.vs b/shader/basic3D.vs
deleted file mode 100644
index 1d23790..0000000
--- a/shader/basic3D.vs
+++ /dev/null
@@ -1,13 +0,0 @@
-#version 130
-
-uniform mat4 pv, m;
-
-in vec3 vertex;
-in vec2 texCoord;
-
-out vec2 tc;
-
-void main(){
-	tc = texCoord;
-	gl_Position = pv*m*vec4(vertex, 1.0);
-}
diff --git a/shader/text.fs b/shader/text.fs
deleted file mode 100644
index 5618a3a..0000000
--- a/shader/text.fs
+++ /dev/null
@@ -1,13 +0,0 @@
-#version 130
-precision highp float;
-
-uniform sampler2D tex;
-uniform vec4 color;
-
-in vec2 tc;
-
-out vec4 c;
-
-void main(){
-	c = texture(tex, tc)*color;
-}
diff --git a/shader/text.vs b/shader/text.vs
deleted file mode 100644
index 1076653..0000000
--- a/shader/text.vs
+++ /dev/null
@@ -1,13 +0,0 @@
-#version 130
-
-uniform mat3 o, m;
-
-in vec2 vertex;
-in vec2 texCoord;
-
-out vec2 tc;
-
-void main(){
-	tc = texCoord;
-	gl_Position = vec4(o*m*vec3(vertex, 1.0), 1.0);
-}
diff --git a/sprite.go b/sprite.go
index 2d1c3e1..5dc8ba8 100644
--- a/sprite.go
+++ b/sprite.go
@@ -15,19 +15,6 @@ type Sprite struct {
 	*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{}
@@ -43,6 +30,19 @@ func NewSprite(tex *Tex) *Sprite {
 	return sprite
 }
 
+// The sprite renderer is a system rendering sprites.
+// It has a 2D position component, 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 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 {
@@ -132,7 +132,7 @@ func (s *SpriteRenderer) GetName() string {
 	return sprite_renderer_name
 }
 
-// Renders sprites.
+// Render sprites.
 func (s *SpriteRenderer) Update(delta float64) {
 	s.Shader.Bind()
 	s.Shader.SendMat3(Default_shader_2D_ortho, *MultMat3(s.Camera.CalcOrtho(), s.CalcModel()))
@@ -147,6 +147,7 @@ func (s *SpriteRenderer) Update(delta float64) {
 
 		s.Shader.SendMat3(Default_shader_2D_model, *s.sprites[i].CalcModel())
 
+		// prevent texture switching when not neccessary
 		if tid != s.sprites[i].Tex.GetId() {
 			tid = s.sprites[i].Tex.GetId()
 			s.sprites[i].Tex.Bind()
diff --git a/text.go b/text.go
new file mode 100644
index 0000000..b213882
--- /dev/null
+++ b/text.go
@@ -0,0 +1,402 @@
+package goga
+
+/*
+import (
+	"core"
+	"dp"
+	"encoding/json"
+	"geo"
+	"github.com/go-gl/gl/v4.5-core/gl"
+	"io/ioutil"
+	"util"
+)
+
+const (
+	char_padding = 2
+)
+
+// Returns a new renderable text object.
+func NewText(font *Font, text string) *Text {
+	t := &Text{id: core.NextId()}
+	t.text = text
+	t.index = dp.NewVBO(gl.ELEMENT_ARRAY_BUFFER)
+	t.vertex = dp.NewVBO(gl.ARRAY_BUFFER)
+	t.texCoord = dp.NewVBO(gl.ARRAY_BUFFER)
+	t.vao = dp.NewVAO()
+	t.SetText(font, text)
+	t.Size = geo.Vec2{1, 1}
+	t.Scale = geo.Vec2{1, 1}
+	t.Visible = true
+
+	return t
+}
+
+type Character struct {
+	char           byte
+	min, max, size geo.Vec2
+	offset         float64
+}
+
+type Font struct {
+	Tex              *dp.Tex
+	tileSize         float64
+	CharPadding      geo.Vec2
+	Space, Tab, Line float64
+	chars            []Character
+}
+
+type jsonChar struct {
+	Char         string
+	X, Y, Offset float64
+}
+
+// Creates a new font from texture. Characters must be added afterwards.
+// The characters must be placed within a grid,
+// the second parameter describes the width and height of one tile in pixel.
+func NewFont(tex *dp.Tex, tileSize int) *Font {
+	font := &Font{}
+	font.Tex = tex
+	font.tileSize = float64(tileSize)
+	font.CharPadding = geo.Vec2{0.05, 0.05}
+	font.Space = 0.3
+	font.Tab = 1.2
+	font.Line = 1
+	font.chars = make([]Character, 0)
+
+	return font
+}
+
+// Loads characters from JSON file.
+// Format:
+//
+// [
+//     {
+//         "char": "a",
+//         "x": 0,
+//         "y": 0,
+//		   "offset": 0
+//     },
+//     ...
+// ]
+//
+// Where x and y start in the upper left corner of the texture, both of type int.
+// Offset is optional and can be used to move a character up or down (relative to others).
+// If cut is set to true, the characters will be true typed.
+func (f *Font) LoadFromJson(path string, cut bool) error {
+	// load file content
+	content, err := ioutil.ReadFile(path)
+
+	if err != nil {
+		return err
+	}
+
+	// read json
+	chars := make([]jsonChar, 0)
+
+	if err = json.Unmarshal(content, &chars); err != nil {
+		return err
+	}
+
+	f.extractChars(chars, cut)
+
+	return nil
+}
+
+func (f *Font) extractChars(chars []jsonChar, cut bool) {
+	for _, char := range chars {
+		if len(char.Char) != 1 {
+			continue
+		}
+
+		var min, max, size geo.Vec2
+
+		if !cut {
+			min = geo.Vec2{char.X * f.tileSize, char.Y * f.tileSize}
+			max = geo.Vec2{min.X + f.tileSize, min.Y + f.tileSize}
+			size = geo.Vec2{1, 1}
+		} else {
+			min, max, size = f.cutChar(int(char.X), int(char.Y))
+		}
+
+		f.chars = append(f.chars, Character{char.Char[0], min, max, size, char.Offset})
+	}
+}
+
+func (f *Font) cutChar(x, y int) (geo.Vec2, geo.Vec2, geo.Vec2) {
+	minX := int(f.Tex.GetSize().X)
+	minY := int(f.Tex.GetSize().Y)
+	maxX := 0
+	maxY := 0
+	rgba := f.Tex.GetRGBA()
+
+	for ry := y * int(f.tileSize); ry < (y+1)*int(f.tileSize); ry++ {
+		for rx := x * int(f.tileSize); rx < (x+1)*int(f.tileSize); rx++ {
+			_, _, _, a := rgba.At(rx, ry).RGBA()
+
+			if a == 0 {
+				continue
+			}
+
+			if rx < minX {
+				minX = rx
+			} else if rx > maxX {
+				maxX = rx
+			}
+
+			if ry < minY {
+				minY = ry
+			} else if ry > maxY {
+				maxY = ry
+			}
+		}
+	}
+
+	minX -= char_padding
+	maxX += char_padding
+	minY -= char_padding
+	maxY += char_padding
+
+	texSize := f.Tex.GetSize()
+	min := geo.Vec2{float64(minX) / texSize.X, float64(maxY) / texSize.Y}
+	max := geo.Vec2{float64(maxX) / texSize.X, float64(minY) / texSize.Y}
+
+	// size
+	size := geo.Vec2{float64(maxX-minX) / f.tileSize, float64(maxY-minY) / f.tileSize}
+
+	return min, max, size
+}
+
+func (f *Font) getChar(char byte) *Character {
+	for _, character := range f.chars {
+		if character.char == char {
+			return &character
+		}
+	}
+
+	return nil
+}
+
+type Text struct {
+	*Actor
+	*Pos2D
+
+	id     int
+	text   string
+	bounds geo.Vec2
+
+	index, vertex, texCoord *dp.VBO
+	vao                     *dp.VAO
+}
+
+// Deletes GL buffers bound to this text.
+func (t *Text) Drop() {
+	t.index.Drop()
+	t.vertex.Drop()
+	t.texCoord.Drop()
+	t.vao.Drop()
+}
+
+// Sets the given string as text and (re)creates buffers.
+func (t *Text) SetText(font *Font, text string) {
+	t.text = text
+
+	indices := make([]uint32, len(text)*6)
+	vertices := make([]float32, len(text)*8)
+	texCoords := make([]float32, len(text)*8)
+	chars := 0
+
+	// create indices
+	var index uint32 = 0
+
+	for i := 0; i < len(text)*6; i += 6 {
+		indices[i] = index
+		indices[i+1] = index + 1
+		indices[i+2] = index + 2
+		indices[i+3] = index + 1
+		indices[i+4] = index + 2
+		indices[i+5] = index + 3
+
+		index += 4
+	}
+
+	// create vertices/texCoords
+	index = 0
+	offset := geo.Vec2{}
+	var width, height float64
+
+	for i := 0; i < len(text)*8 && int(index) < len(text); i += 8 {
+		c := font.getChar(text[index])
+		index++
+
+		// whitespace and new line
+		if text[index-1] == ' ' {
+			offset.X += font.Space
+			i -= 8
+			continue
+		}
+
+		if text[index-1] == '\n' {
+			offset.X = 0
+			offset.Y -= font.Line
+			i -= 8
+			continue
+		}
+
+		if text[index-1] == '\t' {
+			offset.X += font.Tab
+			i -= 8
+			continue
+		}
+
+		// character not found
+		if c == nil {
+			i -= 8
+			continue
+		}
+
+		// usual character
+		vertices[i] = float32(offset.X)
+		vertices[i+1] = float32(offset.Y + c.offset)
+		vertices[i+2] = float32(offset.X + c.size.X)
+		vertices[i+3] = float32(offset.Y + c.offset)
+		vertices[i+4] = float32(offset.X)
+		vertices[i+5] = float32(offset.Y + c.size.Y + c.offset)
+		vertices[i+6] = float32(offset.X + c.size.X)
+		vertices[i+7] = float32(offset.Y + c.size.Y + c.offset)
+
+		texCoords[i] = float32(c.min.X)
+		texCoords[i+1] = float32(c.min.Y)
+		texCoords[i+2] = float32(c.max.X)
+		texCoords[i+3] = float32(c.min.Y)
+		texCoords[i+4] = float32(c.min.X)
+		texCoords[i+5] = float32(c.max.Y)
+		texCoords[i+6] = float32(c.max.X)
+		texCoords[i+7] = float32(c.max.Y)
+
+		offset.X += c.size.X + font.CharPadding.X
+		chars++
+
+		if offset.X > width {
+			width = offset.X
+		}
+
+		if offset.Y*-1+font.Line > height {
+			height = offset.Y*-1 + font.Line
+		}
+	}
+
+	t.bounds = geo.Vec2{width, height}
+
+	// fill GL buffer
+	t.index.Fill(gl.Ptr(indices[:chars*6]), 4, chars*6, gl.STATIC_DRAW)
+	t.vertex.Fill(gl.Ptr(vertices[:chars*8]), 4, chars*8, gl.STATIC_DRAW)
+	t.texCoord.Fill(gl.Ptr(texCoords[:chars*8]), 4, chars*8, gl.STATIC_DRAW)
+
+	util.CheckGLError()
+}
+
+func (t *Text) GetId() int {
+	return t.id
+}
+
+// Returns the text as string.
+func (t *Text) GetText() string {
+	return t.text
+}
+
+// Returns bounds of text, which is the size of characters.
+func (t *Text) GetBounds() geo.Vec2 {
+	return geo.Vec2{t.bounds.X * t.Size.X * t.Scale.X, t.bounds.Y * t.Size.Y * t.Scale.Y}
+}
+
+type TextRenderer struct {
+	Pos2D
+
+	Shader *dp.Shader
+	Camera *Camera
+	Font   *Font
+	Color  geo.Vec4
+	texts  []*Text
+}
+
+// Creates a new text renderer using given shader, camera and font.
+// If shader and/or camera are nil, the default one will be used.
+func NewTextRenderer(shader *dp.Shader, camera *Camera, font *Font) *TextRenderer {
+	renderer := &TextRenderer{}
+	renderer.Shader = shader
+	renderer.Camera = camera
+	renderer.Font = font
+	renderer.Color = geo.Vec4{1, 1, 1, 1}
+	renderer.texts = make([]*Text, 0)
+	renderer.Size = geo.Vec2{1, 1}
+	renderer.Scale = geo.Vec2{1, 1}
+
+	return renderer
+}
+
+// Prepares a text for rendering.
+func (r *TextRenderer) Prepare(text *Text) {
+	text.vao = dp.NewVAO()
+	text.vao.Bind()
+	r.Shader.EnableVertexAttribArrays()
+	text.index.Bind()
+	text.vertex.Bind()
+	text.vertex.AttribPointer(r.Shader.GetAttribLocation(TEXTRENDERER_VERTEX_ATTRIB), 2, gl.FLOAT, false, 0)
+	text.texCoord.Bind()
+	text.texCoord.AttribPointer(r.Shader.GetAttribLocation(TEXTRENDERER_TEXCOORD_ATTRIB), 2, gl.FLOAT, false, 0)
+	text.vao.Unbind()
+}
+
+// Adds text to the renderer.
+func (r *TextRenderer) Add(text *Text) {
+	r.texts = append(r.texts, text)
+}
+
+// Returns text by ID.
+func (r *TextRenderer) Get(id int) *Text {
+	for _, text := range r.texts {
+		if text.GetId() == id {
+			return text
+		}
+	}
+
+	return nil
+}
+
+// Removes text from renderer by ID.
+func (r *TextRenderer) Remove(id int) *Text {
+	for i, text := range r.texts {
+		if text.GetId() == id {
+			r.texts = append(r.texts[:i], r.texts[i+1:]...)
+			return text
+		}
+	}
+
+	return nil
+}
+
+// Removes all sprites.
+func (r *TextRenderer) Clear() {
+	r.texts = make([]*Text, 0)
+}
+
+// Renders sprites.
+func (r *TextRenderer) Render() {
+	r.Shader.Bind()
+	r.Shader.SendMat3(TEXTRENDERER_ORTHO, *geo.MultMat3(r.Camera.CalcOrtho(), r.CalcModel()))
+	r.Shader.SendUniform1i(TEXTRENDERER_TEX, 0)
+	r.Shader.SendUniform4f(TEXTRENDERER_COLOR, float32(r.Color.X), float32(r.Color.Y), float32(r.Color.Z), float32(r.Color.W))
+	r.Font.Tex.Bind()
+
+	for i := range r.texts {
+		if !r.texts[i].Visible {
+			continue
+		}
+
+		r.texts[i].vao.Bind()
+		r.Shader.SendMat3(TEXTRENDERER_MODEL, *r.texts[i].CalcModel())
+
+		gl.DrawElements(gl.TRIANGLES, r.texts[i].index.Size(), gl.UNSIGNED_INT, nil)
+	}
+}
+*/