Rendering now works! Added shaders for reference.

ToDo.md

@@ -3,3 +3,4 @@
 * ~~cleanup resources~~
 * more logging
 * limit FPS
+* fullscreen

game.go

@@ -14,6 +14,31 @@ const (
 	default_height        = uint32(400)
 	default_title         = "Game"
 	default_exit_on_close = true
+
+	// constants for default 2D shader
+	Default_shader_2D_vertex_attrib   = "vertex"
+	Default_shader_2D_texcoord_attrib = "texCoord"
+	Default_shader_2D_ortho           = "o"
+	Default_shader_2D_model           = "m"
+	Default_shader_2D_tex             = "tex"
+
+	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);
+		}`
+	default_shader_2d_fragment_src = `#version 130
+		precision highp float;
+		uniform sampler2D tex;
+		in vec2 tc;
+		out vec4 color;
+		void main(){
+		color = texture(tex, tc);
+		}`
 )
 
 // If set in RunOptions, the function will be called on window resize.
@@ -46,6 +71,10 @@ var (
 	clearBuffer    []uint32
 	viewportWidth  int
 	viewportHeight int
+
+	// Default resources
+	DefaultCamera   *Camera
+	Default2DShader *Shader
 )
 
 func init() {
@@ -130,7 +159,7 @@ func Run(game Game, options *RunOptions) {
 
 	// init go-game
 	log.Print("Initializing goga")
-	initGoga()
+	initGoga(int(width), int(height))
 
 	if options != nil && options.Width > 0 && options.Height > 0 {
 		SetViewport(0, 0, int32(options.Width), int32(options.Height))
@@ -176,6 +205,60 @@ func Run(game Game, options *RunOptions) {
 	}
 }
 
+func initGoga(width, height int) {
+	// default camera
+	DefaultCamera = NewCamera(0, 0, width, height)
+	DefaultCamera.CalcRatio()
+	DefaultCamera.CalcOrtho()
+
+	// default shader
+	shader, err := NewShader(default_shader_2d_vertex_src, default_shader_2d_fragment_src)
+
+	if err != nil {
+		panic(err)
+	}
+
+	Default2DShader = shader
+	Default2DShader.BindAttrib(Default_shader_2D_vertex_attrib)
+	Default2DShader.BindAttrib(Default_shader_2D_texcoord_attrib)
+
+	// settings and registration
+	ClearColorBuffer(true)
+	EnableAlphaBlending(true)
+	AddLoader(&PngLoader{gl.LINEAR, false})
+	AddSystem(NewSpriteRenderer(nil, nil, false))
+}
+
+func cleanup() {
+	// cleanup resources
+	log.Printf("Cleaning up %v resources", len(resources))
+
+	for _, res := range resources {
+		if drop, ok := res.(Dropable); ok {
+			drop.Drop()
+		}
+	}
+
+	// cleanup systems
+	log.Printf("Cleaning up %v systems", len(systems))
+
+	for _, system := range systems {
+		system.Cleanup()
+	}
+
+	// cleanup scenes
+	log.Printf("Cleaning up %v scenes", len(scenes))
+
+	for _, scene := range scenes {
+		scene.Cleanup()
+	}
+
+	// cleanup default
+	log.Print("Cleaning up default resources")
+
+	Default2DShader.Drop()
+}
+
 // Stops the game and closes the window.
 func Stop() {
 	log.Print("Stopping main loop")
@@ -202,10 +285,24 @@ func ClearDepthBuffer(do bool) {
 	}
 }
 
+// Enables/Disables alpha blending by source alpha channel.
+// BLEND = SRC_ALPHA | ONE_MINUS_SRC_ALPHA
+func EnableAlphaBlending(enable bool) {
+	if enable {
+		gl.Enable(gl.BLEND)
+		gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
+	} else {
+		gl.Disable(gl.BLEND)
+	}
+}
+
 // Sets GL viewport.
 func SetViewport(x, y, width, height int32) {
 	viewportWidth = int(width)
 	viewportHeight = int(height)
+	DefaultCamera.SetViewport(int(x), int(y), viewportWidth, viewportHeight)
+	DefaultCamera.CalcRatio()
+	DefaultCamera.CalcOrtho()
 	gl.Viewport(x, y, width, height)
 }
 
@@ -232,33 +329,3 @@ func removeClearBuffer(buffer uint32) {
 		}
 	}
 }
-
-func initGoga() {
-	ClearColorBuffer(true)
-	AddLoader(&PngLoader{gl.LINEAR, false})
-}
-
-func cleanup() {
-	// cleanup resources
-	log.Print("Cleaning up resources")
-
-	for _, res := range resources {
-		if drop, ok := res.(Dropable); ok {
-			drop.Drop()
-		}
-	}
-
-	// cleanup systems
-	log.Print("Cleaning up systems")
-
-	for _, system := range systems {
-		system.Cleanup()
-	}
-
-	// cleanup scenes
-	log.Print("Cleaning up scenes")
-
-	for _, scene := range scenes {
-		scene.Cleanup()
-	}
-}

gl_util.go

@@ -13,3 +13,72 @@ func CheckGLError() {
 		log.Print(error)
 	}
 }
+
+// Creates three VBOs for a 2D rectangle.
+func CreateRectMesh(flip bool) (*VBO, *VBO, *VBO) {
+	ib, vb, tb := createIndexVertexTexCoordBuffer()
+
+	indexData := []uint32{0, 1, 2, 1, 2, 3}
+	vertexData := []float32{0, 0, 1, 0, 0, 1, 1, 1}
+	texData := make([]float32, 8)
+
+	if flip {
+		texData = []float32{0, 0, 1, 0, 0, 1, 1, 1}
+	} else {
+		texData = []float32{0, 1, 1, 1, 0, 0, 1, 0}
+	}
+
+	ib.Fill(gl.Ptr(indexData), 4, 6, gl.STATIC_DRAW)
+	vb.Fill(gl.Ptr(vertexData), 4, 8, gl.STATIC_DRAW)
+	tb.Fill(gl.Ptr(texData), 4, 8, gl.STATIC_DRAW)
+
+	return ib, vb, tb
+}
+
+// Creates three VBOs for a 3D cube mesh.
+// Texture coordinates won't map properly.
+// This function is supposed to be used for 3D testing.
+func CreateCubeMesh() (*VBO, *VBO, *VBO) {
+	ib, vb, tb := createIndexVertexTexCoordBuffer()
+
+	indexData := []uint32{3, 1, 0,
+		0, 2, 3,
+		7, 5, 1,
+		1, 3, 7,
+		6, 4, 5,
+		5, 7, 6,
+		2, 0, 4,
+		4, 6, 2,
+		7, 3, 2,
+		2, 6, 7,
+		1, 5, 4,
+		4, 0, 1}
+	vertexData := []float32{0, 0, 0,
+		1, 0, 0,
+		0, 1, 0,
+		1, 1, 0,
+		0, 0, 1,
+		1, 0, 1,
+		0, 1, 1,
+		1, 1, 1}
+	texData := []float32{0, 0,
+		1, 0,
+		0, 1,
+		1, 1,
+		1, 1,
+		0, 1,
+		1, 0,
+		0, 0}
+
+	ib.Fill(gl.Ptr(indexData), 4, 36, gl.STATIC_DRAW)
+	vb.Fill(gl.Ptr(vertexData), 4, 24, gl.STATIC_DRAW)
+	tb.Fill(gl.Ptr(texData), 4, 12, gl.STATIC_DRAW)
+
+	return ib, vb, tb
+}
+
+func createIndexVertexTexCoordBuffer() (*VBO, *VBO, *VBO) {
+	return NewVBO(gl.ELEMENT_ARRAY_BUFFER),
+		NewVBO(gl.ARRAY_BUFFER),
+		NewVBO(gl.ARRAY_BUFFER)
+}

pos.go

@@ -0,0 +1,85 @@
+package goga
+
+// Position component for 2D objects.
+type Pos2D struct {
+	Pos, Size, Scale, RotPoint Vec2
+	Rot                        float64
+	Visible                    bool
+	M                          Mat3
+}
+
+// Creates a default initialized Pos2D.
+func NewPos2D() *Pos2D {
+	m := Mat3{}
+	m.Identity()
+	return &Pos2D{Size: Vec2{1, 1}, Scale: Vec2{1, 1}, Visible: true, M: m}
+}
+
+// Calculates model matrix for 2D positioning.
+func (p *Pos2D) CalcModel() *Mat3 {
+	p.M.Identity()
+	p.M.Translate(Vec2{p.Pos.X + p.RotPoint.X, p.Pos.Y + p.RotPoint.Y})
+	p.M.Rotate(p.Rot)
+	p.M.Translate(Vec2{-p.RotPoint.X, -p.RotPoint.Y})
+	p.M.Scale(p.Size)
+	p.M.Scale(p.Scale)
+
+	return &p.M
+}
+
+// Returns the center of object.
+// Assumes y = 0 is bottom left corner, if not you have to subtract height of object.
+func (p *Pos2D) GetCenter() Vec2 {
+	return Vec2{p.Pos.X + (p.Size.X*p.Scale.X)/2, p.Pos.Y + (p.Size.Y*p.Scale.Y)/2}
+}
+
+// Returns true when given point is within rectangle of this object.
+func (p *Pos2D) PointInRect(point Vec2) bool {
+	return point.X > p.Pos.X && point.X < p.Pos.X+p.Size.X*p.Scale.X && point.Y > p.Pos.Y && point.Y < p.Pos.Y+p.Size.Y*p.Scale.Y
+}
+
+// Position component for 3D objects
+type Pos3D struct {
+	Pos, Size, Scale, RotPoint, Rot Vec3
+	Visible                         bool
+	M                               Mat4
+}
+
+// Creates a default initialized Pos3D.
+func NewPos3D() *Pos3D {
+	m := Mat4{}
+	m.Identity()
+	return &Pos3D{Size: Vec3{1, 1, 1}, Scale: Vec3{1, 1, 1}, Visible: true, M: m}
+}
+
+// Calculates model matrix for 3D positioning.
+func (p *Pos3D) CalcModel() *Mat4 {
+	p.M.Identity()
+	p.M.Translate(Vec3{p.Pos.X + p.RotPoint.X, p.Pos.Y + p.RotPoint.Y, p.Pos.Z + p.RotPoint.Z})
+	p.M.Rotate(p.Rot.X, Vec3{1, 0, 0})
+	p.M.Rotate(p.Rot.Y, Vec3{0, 1, 0})
+	p.M.Rotate(p.Rot.Z, Vec3{0, 0, 1})
+	p.M.Translate(Vec3{-p.RotPoint.X, -p.RotPoint.Y, -p.RotPoint.Z})
+	p.M.Scale(p.Size)
+	p.M.Scale(p.Scale)
+
+	return &p.M
+}
+
+// Returns the center of object.
+// Assumes y = 0 is bottom left corner, if not you have to subtract height of object.
+func (p *Pos3D) GetCenter() Vec3 {
+	return Vec3{p.Pos.X + (p.Size.X*p.Scale.X)/2, p.Pos.Y + (p.Size.Y*p.Scale.Y)/2, p.Pos.Z + (p.Size.Z*p.Scale.Z)/2}
+}
+
+// Centers given sprite within rectangle.
+// Does nothing if sprite is nil.
+// TODO
+/*func CenterSprite(sprite *Sprite, x, y, width, height int) {
+	if sprite == nil {
+		return
+	}
+
+	sprite.Pos.X = (float64(width-x) - sprite.Size.X) / 2
+	sprite.Pos.Y = (float64(height-y) - sprite.Size.Y) / 2
+}*/

shader.go

@@ -3,6 +3,7 @@ package goga
 import (
 	"errors"
 	"github.com/go-gl/gl/v4.5-core/gl"
+	"log"
 	"strings"
 )
 
@@ -26,8 +27,9 @@ func NewShader(vertexShader, fragmentShader string) (*Shader, error) {
 	shader.program = gl.CreateProgram()
 	shader.vertex = gl.CreateShader(gl.VERTEX_SHADER)
 	shader.fragment = gl.CreateShader(gl.FRAGMENT_SHADER)
+	CheckGLError()
 
-	if err := compileShader(&shader.vertex, vertexShader+NullTerminator); err != nil {
+	if err := compileShader(shader.vertex, vertexShader+NullTerminator); err != nil {
 		gl.DeleteShader(shader.vertex)
 		gl.DeleteShader(shader.fragment)
 		shader.Drop()
@@ -35,7 +37,7 @@ func NewShader(vertexShader, fragmentShader string) (*Shader, error) {
 		return nil, err
 	}
 
-	if err := compileShader(&shader.fragment, fragmentShader+NullTerminator); err != nil {
+	if err := compileShader(shader.fragment, fragmentShader+NullTerminator); err != nil {
 		gl.DeleteShader(shader.vertex)
 		gl.DeleteShader(shader.fragment)
 		shader.Drop()
@@ -54,21 +56,26 @@ func NewShader(vertexShader, fragmentShader string) (*Shader, error) {
 		return nil, err
 	}
 
+	CheckGLError()
+
 	// we don't need to keep them in memory
 	gl.DetachShader(shader.program, shader.vertex)
 	gl.DetachShader(shader.program, shader.fragment)
 	gl.DeleteShader(shader.vertex)
 	gl.DeleteShader(shader.fragment)
+	CheckGLError()
 
 	return shader, nil
 }
 
-func compileShader(shader *uint32, source string) error {
-	csrc := gl.Str(source)
-	gl.ShaderSource(*shader, 1, &csrc, nil)
-	gl.CompileShader(*shader)
+func compileShader(shader uint32, source string) error {
+	log.Print("Compiling shader: " + source)
+	csrc, free := gl.Strs(source)
+	gl.ShaderSource(shader, 1, csrc, nil)
+	gl.CompileShader(shader)
+	free()
 
-	if err := shaderCheckError(*shader); err != nil {
+	if err := shaderCheckError(shader); err != nil {
 		return err
 	}
 

shader/basic2D.fs

@@ -0,0 +1,12 @@
+#version 130
+precision highp float;
+
+uniform sampler2D tex;
+
+in vec2 tc;
+
+out vec4 color;
+
+void main(){
+	color = texture(tex, tc);
+}

shader/basic2D.vs

@@ -0,0 +1,13 @@
+#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);
+}

shader/basic3D.fs

@@ -0,0 +1,12 @@
+#version 130
+precision highp float;
+
+uniform sampler2D tex;
+
+in vec2 tc;
+
+out vec4 color;
+
+void main(){
+	color = texture(tex, tc);
+}

shader/basic3D.vs

@@ -0,0 +1,13 @@
+#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);
+}

shader/text.fs

@@ -0,0 +1,13 @@
+#version 130
+precision highp float;
+
+uniform sampler2D tex;
+uniform vec4 color;
+
+in vec2 tc;
+
+out vec4 c;
+
+void main(){
+	c = texture(tex, tc)*color;
+}

shader/text.vs

@@ -0,0 +1,13 @@
+#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);
+}

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)
+	}
+}

system.go

@@ -10,8 +10,8 @@ import ()
 type System interface {
 	Update(float64)
 	Cleanup()
-	Add(*Actor) bool
-	Remove(*Actor) bool
+	Add(interface{}) bool
+	Remove(interface{}) bool
 	RemoveById(ActorId) bool
 	RemoveAll()
 	Len() int