Add opengl.Context.NewBuffer

graphics.go

@@ -27,7 +27,7 @@ const (
 	FilterLinear
 )
 
-func glFilter(c *opengl.Context, filter Filter) opengl.Filter {
+func glFilter(c *opengl.Context, filter Filter) opengl.FilterType {
 	switch filter {
 	case FilterNearest:
 		return c.Nearest

internal/graphics/internal/shader/drawtexture.go

@@ -41,8 +41,6 @@ type TextureQuads interface {
 
 var initialized = false
 
-const size = 10000
-
 // TODO: Use unsafe.SizeOf?
 const uint16Size = 2
 const float32Size = 4
@@ -54,31 +52,13 @@ func DrawTexture(c *opengl.Context, texture opengl.Texture, projectionMatrix [4]
 		if err := initialize(c); err != nil {
 			return err
 		}
-
-		vertexBuffer := gl.GenBuffer()
-		vertexBuffer.Bind(gl.ARRAY_BUFFER)
-		s := float32Size * stride * size
-		gl.BufferData(gl.ARRAY_BUFFER, s, nil, gl.DYNAMIC_DRAW)
-
-		indexBuffer := gl.GenBuffer()
-		indexBuffer.Bind(gl.ELEMENT_ARRAY_BUFFER)
-		indices := make([]uint16, 6*size)
-		for i := uint16(0); i < size; i++ {
-			indices[6*i+0] = 4*i + 0
-			indices[6*i+1] = 4*i + 1
-			indices[6*i+2] = 4*i + 2
-			indices[6*i+3] = 4*i + 1
-			indices[6*i+4] = 4*i + 2
-			indices[6*i+5] = 4*i + 3
-		}
-		gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, uint16Size*len(indices), indices, gl.STATIC_DRAW)
-
 		initialized = true
 	}
 
 	if quads.Len() == 0 {
 		return nil
 	}
+
 	// TODO: Check performance
 	program := useProgramColorMatrix(glMatrix(projectionMatrix), geo, color)
 

internal/graphics/internal/shader/program.go

@@ -21,6 +21,8 @@ import (
 var programColorMatrix opengl.Program
 
 func initialize(c *opengl.Context) error {
+	const size = 10000
+
 	var err error
 	shaders[shaderVertex].native, err = c.NewShader(c.VertexShader, shaders[shaderVertex].source)
 	if err != nil {
@@ -39,6 +41,22 @@ func initialize(c *opengl.Context) error {
 		shaders[shaderColorMatrix].native,
 	}
 	programColorMatrix, err = c.NewProgram(shaders)
+
+	const stride = 4 * 4
+	s := float32Size * stride * size
+	c.NewBuffer(c.ArrayBuffer, s, nil, c.DynamicDraw)
+
+	indices := make([]uint16, 6*size)
+	for i := uint16(0); i < size; i++ {
+		indices[6*i+0] = 4*i + 0
+		indices[6*i+1] = 4*i + 1
+		indices[6*i+2] = 4*i + 2
+		indices[6*i+3] = 4*i + 1
+		indices[6*i+4] = 4*i + 2
+		indices[6*i+5] = 4*i + 3
+	}
+	c.NewBuffer(c.ElementArrayBuffer, uint16Size*len(indices), indices, c.StaticDraw)
+
 	return err
 }
 

internal/graphics/texture.go

@@ -54,7 +54,7 @@ func (t *Texture) Size() (width, height int) {
 	return t.width, t.height
 }
 
-func NewTexture(c *opengl.Context, width, height int, filter opengl.Filter) (*Texture, error) {
+func NewTexture(c *opengl.Context, width, height int, filter opengl.FilterType) (*Texture, error) {
 	w := internal.NextPowerOf2Int(width)
 	h := internal.NextPowerOf2Int(height)
 	if w < 4 {
@@ -70,7 +70,7 @@ func NewTexture(c *opengl.Context, width, height int, filter opengl.Filter) (*Te
 	return &Texture{native, width, height}, nil
 }
 
-func NewTextureFromImage(c *opengl.Context, img image.Image, filter opengl.Filter) (*Texture, error) {
+func NewTextureFromImage(c *opengl.Context, img image.Image, filter opengl.FilterType) (*Texture, error) {
 	origSize := img.Bounds().Size()
 	if origSize.X < 4 {
 		return nil, errors.New("width must be equal or more than 4.")

internal/opengl/context.go

@@ -20,19 +20,10 @@ import (
 	"github.com/go-gl/gl"
 )
 
-type Filter int
+type FilterType int
-
-const (
-	filterNearest Filter = gl.NEAREST
-	filterLinear         = gl.LINEAR
-)
-
 type ShaderType int
-
+type BufferType int
-const (
+type BufferUsageType int
-	shaderTypeVertex   ShaderType = gl.VERTEX_SHADER
-	shaderTypeFragment            = gl.FRAGMENT_SHADER
-)
 
 type Texture gl.Texture
 
@@ -127,18 +118,26 @@ func (u UniformLocation) Uniform1i(v int) {
 }
 
 type Context struct {
-	Nearest        Filter
+	Nearest            FilterType
-	Linear         Filter
+	Linear             FilterType
-	VertexShader   ShaderType
+	VertexShader       ShaderType
-	FragmentShader ShaderType
+	FragmentShader     ShaderType
+	ArrayBuffer        BufferType
+	ElementArrayBuffer BufferType
+	DynamicDraw        BufferUsageType
+	StaticDraw         BufferUsageType
 }
 
 func NewContext() *Context {
 	c := &Context{
-		Nearest:        filterNearest,
+		Nearest:            gl.NEAREST,
-		Linear:         filterLinear,
+		Linear:             gl.LINEAR,
-		VertexShader:   shaderTypeVertex,
+		VertexShader:       gl.VERTEX_SHADER,
-		FragmentShader: shaderTypeFragment,
+		FragmentShader:     gl.FRAGMENT_SHADER,
+		ArrayBuffer:        gl.ARRAY_BUFFER,
+		ElementArrayBuffer: gl.ELEMENT_ARRAY_BUFFER,
+		DynamicDraw:        gl.DYNAMIC_DRAW,
+		StaticDraw:         gl.STATIC_DRAW,
 	}
 	c.init()
 	return c
@@ -152,7 +151,7 @@ func (c *Context) init() {
 	gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
 }
 
-func (c *Context) NewTexture(width, height int, pixels []uint8, filter Filter) (Texture, error) {
+func (c *Context) NewTexture(width, height int, pixels []uint8, filter FilterType) (Texture, error) {
 	t := gl.GenTexture()
 	if t < 0 {
 		return 0, errors.New("glGenTexture failed")
@@ -216,3 +215,8 @@ func (c *Context) NewProgram(shaders []Shader) (Program, error) {
 	}
 	return Program(p), nil
 }
+
+func (c *Context) NewBuffer(bufferType BufferType, size int, ptr interface{}, bufferUsageType BufferUsageType) {
+	gl.GenBuffer().Bind(gl.GLenum(bufferType))
+	gl.BufferData(gl.GLenum(bufferType), size, ptr, gl.GLenum(bufferUsageType))
+}