// Creating a RenderObject with a given shaderProgram, texture, and set of
// vertices.
func CreateRenderObject(shaderProgram ShaderProgram, texture Texture, vertices []float32) *RenderObject {
renderObject := new(RenderObject)
// Creating the basic information.
renderObject.shaderProgram = uint32(shaderProgram)
renderObject.texture = uint32(texture)
gl.GenVertexArrays(1, &renderObject.vao)
gl.GenBuffers(1, &renderObject.vbo)
gl.GenBuffers(1, &renderObject.ebo)
// Filling the RenderObject with information.
gl.BindVertexArray(renderObject.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, renderObject.vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, renderObject.ebo)
vertOrder := []uint32{
0, 1, 2,
2, 3, 0,
}
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(vertOrder)*4, gl.Ptr(vertOrder), gl.STATIC_DRAW)
// Loading up vertex attributes.
vertAttrib := uint32(gl.GetAttribLocation(renderObject.shaderProgram, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 2, gl.FLOAT, false, 4*4, gl.PtrOffset(0))
// Loading up texture attributes.
texAttrib := uint32(gl.GetAttribLocation(renderObject.shaderProgram, gl.Str("vertTexCoord\x00")))
gl.EnableVertexAttribArray(texAttrib)
gl.VertexAttribPointer(texAttrib, 2, gl.FLOAT, false, 4*4, gl.PtrOffset(2*4))
return renderObject
}
func LoadText(f *Font) (t *Text) {
t = new(Text)
t.font = f
// text hover values
// "resting state" of a text object is the min scale
t.ScaleMin = 1.0
t.ScaleMax = 1.1
t.SetScale(1)
// size of glfloat
glfloat_size := int32(4)
// stride of the buffered data
xy_count := int32(2)
stride := xy_count + int32(2)
gl.GenVertexArrays(1, &t.vao)
gl.GenBuffers(1, &t.vbo)
gl.GenBuffers(1, &t.ebo)
// vao
gl.BindVertexArray(t.vao)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, t.font.textureID)
// vbo
// specify the buffer for which the VertexAttribPointer calls apply
gl.BindBuffer(gl.ARRAY_BUFFER, t.vbo)
gl.EnableVertexAttribArray(t.font.centeredPosition)
gl.VertexAttribPointer(
t.font.centeredPosition,
2,
gl.FLOAT,
false,
glfloat_size*stride,
gl.PtrOffset(0),
)
gl.EnableVertexAttribArray(t.font.uv)
gl.VertexAttribPointer(
t.font.uv,
2,
gl.FLOAT,
false,
glfloat_size*stride,
gl.PtrOffset(int(glfloat_size*xy_count)),
)
// ebo
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, t.ebo)
// i am guessing that order is important here
gl.BindVertexArray(0)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
return t
}
func CreateSprite(t Texture) (s Sprite, err error) {
s.texture = t
s.shader, err = CreateShader(vertexShader, fragmentShader)
if err != nil {
return s, err
}
gl.GenBuffers(1, &s.ebo)
gl.GenBuffers(1, &s.vbo)
gl.GenVertexArrays(1, &s.vao)
gl.BindVertexArray(s.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, s.vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, s.ebo)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(indices)*4, gl.Ptr(indices), gl.STATIC_DRAW)
err = s.shader.SetAttrib("vert", 2, gl.FLOAT, 4*4, 0)
err = s.shader.SetAttrib("vertTexCoord", 2, gl.FLOAT, 4*4, 2*4)
gl.BindVertexArray(0)
return s, err
}
func createPlane(x0, y0, x1, y1 float32, verts [12]float32, indexes [6]uint32, uvs [8]float32, normals [12]float32) *Renderable {
const floatSize = 4
const uintSize = 4
r := NewRenderable()
gl.GenVertexArrays(1, &r.Vao)
r.FaceCount = 2
// create a VBO to hold the vertex data
gl.GenBuffers(1, &r.VertVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.VertVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(verts), gl.Ptr(&verts[0]), gl.STATIC_DRAW)
// create a VBO to hold the uv data
gl.GenBuffers(1, &r.UvVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.UvVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(uvs), gl.Ptr(&uvs[0]), gl.STATIC_DRAW)
// create a VBO to hold the normals data
gl.GenBuffers(1, &r.NormsVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.NormsVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(normals), gl.Ptr(&normals[0]), gl.STATIC_DRAW)
// create a VBO to hold the face indexes
gl.GenBuffers(1, &r.ElementsVBO)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.ElementsVBO)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, uintSize*len(indexes), gl.Ptr(&indexes[0]), gl.STATIC_DRAW)
return r
}
func (p *Program) createVAO() error {
gl.GenVertexArrays(1, &p.vao)
if e := gl.GetError(); e != 0 {
return fmt.Errorf("ERROR gl.GenVertexArray %X", e)
}
gl.BindVertexArray(p.vao)
if e := gl.GetError(); e != 0 {
return fmt.Errorf("ERROR array.Bind %X", e)
}
return nil
}
//CreateVertexArray is a "constructor" of vertex array, hence returns a opengl
//mesh, specifically a cube for testing
func CreateVertexArray() VertexArray {
var vertexArray VertexArray
cubeVertices := vertexArray.PosData()
gl.GenVertexArrays(1, &vertexArray.handleVAO)
gl.BindVertexArray(vertexArray.handleVAO)
gl.GenBuffers(1, &vertexArray.handleVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, vertexArray.handleVBO)
gl.BufferData(gl.ARRAY_BUFFER, len(cubeVertices)*4, gl.Ptr(cubeVertices), gl.STATIC_DRAW)
return vertexArray
}
func CreateVAO() (array uint32, err error) {
gl.GenVertexArrays(1, &array)
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR gl.GenVertexArray %X", e)
return
}
gl.BindVertexArray(array)
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR array.Bind %X", e)
return
}
return
}
func CreateBuffers() {
var err error
program, err = MakeProgram(VertexShader(), FragmentShader())
// defer program.Delete()
if err != nil {
fmt.Println("Error loading shaders: " + err.Error())
panic("error loading shaders")
}
gl.BindFragDataLocation(program, 0, gl.Str("color\x00"))
MVPid = gl.GetUniformLocation(program, gl.Str("MVP\x00"))
lightpositionID = gl.GetUniformLocation(program, gl.Str("light.position\x00"))
lightintensitiesID = gl.GetUniformLocation(program, gl.Str("light.intensities\x00"))
lightattenuationID = gl.GetUniformLocation(program, gl.Str("light.attenuation\x00"))
lightambientCoeficientID = gl.GetUniformLocation(program, gl.Str("light.ambientCoeficient\x00"))
cameraPositionID = gl.GetUniformLocation(program, gl.Str("cameraPosition\x00"))
// View := mathgl.LookAt(0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0)
// viewM = View
gl.DepthFunc(gl.LEQUAL)
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
// var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
// var vbo uint32
gl.GenBuffers(1, &vbo)
// gl.GenBuffers(1, &elementvbo)
// fmt.Println(program)
gl.UseProgram(program)
for idx, img := range aggregateImages {
bindAggregateImage(img, idx)
}
}
// Creating a LineReader with an initial list of points.
func NewLineRender(shaderProgram ShaderProgram, color Color, static bool, weight float32, points []Point) *LineRender {
lr := new(LineRender)
// Setting the values non-changing values.
lr.shaderProgram = uint32(shaderProgram)
lr.color = color
lr.static = static
lr.weight = weight
// Setting up some OpenGL information.
gl.GenVertexArrays(1, &lr.vao)
gl.GenBuffers(1, &lr.vbo)
gl.GenBuffers(1, &lr.ebo)
lr.UpdatePoints(points)
return lr
}
func CreateContext(width, height int) Context {
vertexShader := `
#version 330
uniform mat4 projection;
uniform mat4 camera;
uniform mat4 model;
in vec3 vert;
void main() {
gl_Position = projection * camera * model * vec4(vert, 1);
}
` + "\x00"
fragmentShader := `
#version 330
uniform vec4 color;
out vec4 outputColor;
void main() {
outputColor = color;
}
` + "\x00"
vertices := []float32{
0.0, 0.0, 0.0,
1.0, 0.0, 0.0,
1.0, 1.0, 0.0,
1.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 0.0, 0.0,
}
if err := glfw.Init(); err != nil {
log.Fatalln("failed to initialize glfw:", err)
}
// defer glfw.Terminate()
glfw.WindowHint(glfw.Resizable, glfw.False)
glfw.WindowHint(glfw.ContextVersionMajor, 3)
glfw.WindowHint(glfw.ContextVersionMinor, 3)
glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
window, err := glfw.CreateWindow(width, height, "OpenGL", nil, nil)
if err != nil {
panic(err)
}
window.MakeContextCurrent()
if err := gl.Init(); err != nil {
panic(err)
}
program, err := newProgram(vertexShader, fragmentShader)
if err != nil {
panic(err)
}
gl.UseProgram(program)
projection := mgl32.Ortho2D(0, 800, 0, 600)
projectionUniform := gl.GetUniformLocation(program, gl.Str("projection\x00"))
gl.UniformMatrix4fv(projectionUniform, 1, false, &projection[0])
camera := mgl32.LookAtV(mgl32.Vec3{0, 0, 0.5}, mgl32.Vec3{0, 0, 0}, mgl32.Vec3{0, 1, 0})
cameraUniform := gl.GetUniformLocation(program, gl.Str("camera\x00"))
gl.UniformMatrix4fv(cameraUniform, 1, false, &camera[0])
model := mgl32.Ident4()
modelUniform := gl.GetUniformLocation(program, gl.Str("model\x00"))
gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])
var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
var vbo uint32
gl.GenBuffers(1, &vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
vertAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 3*4, gl.PtrOffset(0))
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
return Context{Window: window, program: program}
}
func main() {
vertices, normals := obj.Parse(os.Args[1])
// initialize GLFW
if err := glfw.Init(); err != nil {
panic(err)
}
defer glfw.Terminate()
// set opengl core profile 3.3
glfw.WindowHint(glfw.ContextVersionMajor, 3)
glfw.WindowHint(glfw.ContextVersionMinor, 3)
glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
window, err := glfw.CreateWindow(640, 480, "GOpenGL", nil, nil)
if err != nil {
panic(err)
}
window.MakeContextCurrent()
// initialise OpenGL library
if err := gl.Init(); err != nil {
panic(err)
}
// link program from shaders
program, err := newProgram("vertex.glsl", "fragment.glsl")
if err != nil {
panic(err)
}
gl.UseProgram(program)
// vertex attribute object holds links between attributes and vbo
var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
// vertex buffer with per-vertex data
var vbo [2]uint32
gl.GenBuffers(2, &vbo[0])
// position data
gl.BindBuffer(gl.ARRAY_BUFFER, vbo[0])
gl.BufferData(gl.ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
// set up position attribute with layout of vertices
posAttrib := uint32(gl.GetAttribLocation(program, gl.Str("position\x00")))
gl.VertexAttribPointer(posAttrib, 3, gl.FLOAT, false, 3*4, gl.PtrOffset(0))
gl.EnableVertexAttribArray(posAttrib)
// normal data
gl.BindBuffer(gl.ARRAY_BUFFER, vbo[1])
gl.BufferData(gl.ARRAY_BUFFER, len(normals)*4, gl.Ptr(normals), gl.STATIC_DRAW)
normAttrib := uint32(gl.GetAttribLocation(program, gl.Str("normal\x00")))
gl.VertexAttribPointer(normAttrib, 3, gl.FLOAT, false, 3*4, gl.PtrOffset(0))
gl.EnableVertexAttribArray(normAttrib)
uniModel := gl.GetUniformLocation(program, gl.Str("model\x00"))
uniView := gl.GetUniformLocation(program, gl.Str("view\x00"))
uniProj := gl.GetUniformLocation(program, gl.Str("proj\x00"))
matView := mgl32.LookAt(2.0, 2.0, 2.0,
0.0, 0.0, 0.0,
0.0, 0.0, 1.0)
gl.UniformMatrix4fv(uniView, 1, false, &matView[0])
matProj := mgl32.Perspective(mgl32.DegToRad(45.0), 640.0/480.0, 1.0, 10.0)
gl.UniformMatrix4fv(uniProj, 1, false, &matProj[0])
uniLightDir := gl.GetUniformLocation(program, gl.Str("lightDir\x00"))
uniLightCol := gl.GetUniformLocation(program, gl.Str("lightCol\x00"))
gl.Uniform3f(uniLightDir, -0.5, 0.0, -1.0)
gl.Uniform3f(uniLightCol, 0.0, 0.5, 0.5)
startTime := glfw.GetTime()
gl.Enable(gl.DEPTH_TEST)
gl.ClearColor(1.0, 1.0, 1.0, 1.0)
for !window.ShouldClose() {
// clear buffer
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
matRot := mgl32.HomogRotate3DZ(float32(glfw.GetTime() - startTime))
gl.UniformMatrix4fv(uniModel, 1, false, &matRot[0])
gl.DrawArrays(gl.TRIANGLES, 0, int32(len(vertices)))
window.SwapBuffers()
glfw.PollEvents()
}
}
func main() {
// init glfw
if err := glfw.Init(); err != nil {
panic(err)
}
defer glfw.Terminate()
glfw.WindowHint(glfw.Resizable, glfw.False)
glfw.WindowHint(glfw.ContextVersionMajor, 4)
glfw.WindowHint(glfw.ContextVersionMinor, 1)
glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
// make an application window
window, err := glfw.CreateWindow(windowWidth, windowHeight, "Hello", nil, nil)
if err != nil {
panic(err)
}
window.MakeContextCurrent()
// init gl
if err := gl.Init(); err != nil {
panic(err)
}
fmt.Println("OpenGL version", gl.GoStr(gl.GetString(gl.VERSION)))
// create vertex & fragment shader
program, err := newProgram(vertexShader, fragmentShader)
if err != nil {
panic(err)
}
gl.UseProgram(program)
gl.BindFragDataLocation(program, 0, gl.Str("fc\x00"))
points := []float32{
-0.5, -0.5,
0.5, 0.5,
0.5, -0.5,
-0.5, 0.5,
}
vertices := []uint32{
0, 2, 1, 3,
}
// configure the vertex data
var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
defer gl.BindVertexArray(0)
var vbo uint32
gl.GenBuffers(1, &vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(points)*4, gl.Ptr(points), gl.STATIC_DRAW)
var ibo uint32
gl.GenBuffers(1, &ibo)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, ibo)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
vertAttrib := uint32(gl.GetAttribLocation(program, gl.Str("pv\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 2, gl.FLOAT, false, 2*4, gl.PtrOffset(0))
// global settings
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(1.0, 1.0, 1.0, 1.0)
for !window.ShouldClose() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
gl.UseProgram(program)
gl.BindVertexArray(vao)
gl.DrawElements(gl.LINE_LOOP, 4, gl.UNSIGNED_INT, gl.PtrOffset(0))
window.SwapBuffers()
glfw.PollEvents()
}
}
func createMeshes(objs []*obj) []*mesh {
var vertexTable []*objVertex
var normalTable []*objNormal
var texCoordTable []*objTexCoord
var vertices []float32
var normals []float32
var texCoords []float32
elementIndexMap := map[objFaceElement]uint16{}
var nextIndex uint16
var meshes []*mesh
var iboNames []uint32
for _, o := range objs {
for _, v := range o.vertices {
vertexTable = append(vertexTable, v)
}
for _, n := range o.normals {
normalTable = append(normalTable, n)
}
for _, tc := range o.texCoords {
texCoordTable = append(texCoordTable, tc)
}
var indices []uint16
for _, f := range o.faces {
for _, e := range f {
if _, exists := elementIndexMap[e]; !exists {
elementIndexMap[e] = nextIndex
nextIndex++
v := vertexTable[e.vertexIndex-1]
vertices = append(vertices, v.x, v.y, v.z)
n := normalTable[e.normalIndex-1]
normals = append(normals, n.x, n.y, n.z)
// Flip the y-axis to convert from OBJ to OpenGL.
// OpenGL considers the origin to be lower left.
// OBJ considers the origin to be upper left.
tc := texCoordTable[e.texCoordIndex-1]
texCoords = append(texCoords, tc.s, 1.0-tc.t)
}
indices = append(indices, elementIndexMap[e])
}
}
meshes = append(meshes, &mesh{
id: o.id,
count: int32(len(indices)),
})
iboNames = append(iboNames, createElementArrayBuffer(indices))
}
log.Printf("vertices: %d", len(vertexTable))
log.Printf("normals: %d", len(normalTable))
log.Printf("texCoords: %d", len(texCoordTable))
vbo := createArrayBuffer(vertices)
nbo := createArrayBuffer(normals)
tbo := createArrayBuffer(texCoords)
const (
positionLocation = iota
normalLocation
texCoordLocation
)
for i, m := range meshes {
gl.GenVertexArrays(1, &m.vao)
gl.BindVertexArray(m.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.EnableVertexAttribArray(positionLocation)
gl.VertexAttribPointer(positionLocation, 3, gl.FLOAT, false, 0, gl.PtrOffset(0))
gl.BindBuffer(gl.ARRAY_BUFFER, nbo)
gl.EnableVertexAttribArray(normalLocation)
gl.VertexAttribPointer(normalLocation, 3, gl.FLOAT, false, 0, gl.PtrOffset(0))
gl.BindBuffer(gl.ARRAY_BUFFER, tbo)
gl.EnableVertexAttribArray(texCoordLocation)
gl.VertexAttribPointer(texCoordLocation, 2, gl.FLOAT, false, 0, gl.PtrOffset(0))
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, iboNames[i])
gl.BindVertexArray(0)
}
return meshes
}
func loadBoundingBox(f *Font, X1 Point, X2 Point) (b *BoundingBox, err error) {
b = new(BoundingBox)
b.font = f
// create shader program and define attributes and uniforms
b.program, err = NewProgram(boxVertexShaderSource, boxFragmentShaderSource)
if err != nil {
return b, err
}
// ebo, vbo data
b.vboIndexCount = 4 * 2 // 4 indexes per bounding box (containing 2 position)
b.eboIndexCount = 6 // each rune requires 6 triangle indices for a quad
b.vboData = make([]float32, b.vboIndexCount, b.vboIndexCount)
b.eboData = make([]int32, b.eboIndexCount, b.eboIndexCount)
b.makeBufferData(X1, X2)
if f.IsDebug {
fmt.Printf("bounding %v %v\n", X1, X2)
fmt.Printf("bounding vbo data\n%v\n", b.vboData)
fmt.Printf("bounding ebo data\n%v\n", b.eboData)
}
// attributes
b.centeredPosition = uint32(gl.GetAttribLocation(b.program, gl.Str("centered_position\x00")))
// uniforms
b.finalPositionUniform = gl.GetUniformLocation(b.program, gl.Str("final_position\x00"))
b.orthographicMatrixUniform = gl.GetUniformLocation(b.program, gl.Str("orthographic_matrix\x00"))
// size of glfloat
glfloatSize := int32(4)
gl.GenVertexArrays(1, &b.vao)
gl.GenBuffers(1, &b.vbo)
gl.GenBuffers(1, &b.ebo)
// vao
gl.BindVertexArray(b.vao)
// vbo
// specify the buffer for which the VertexAttribPointer calls apply
gl.BindBuffer(gl.ARRAY_BUFFER, b.vbo)
gl.EnableVertexAttribArray(b.centeredPosition)
gl.VertexAttribPointer(
b.centeredPosition,
2,
gl.FLOAT,
false,
0,
gl.PtrOffset(0),
)
gl.BufferData(gl.ARRAY_BUFFER, int(glfloatSize)*b.vboIndexCount, gl.Ptr(b.vboData), gl.DYNAMIC_DRAW)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, b.ebo)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, int(glfloatSize)*b.eboIndexCount, gl.Ptr(b.eboData), gl.DYNAMIC_DRAW)
gl.BindVertexArray(0)
// not necesssary, but i just want to better understand using vertex arrays
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
return b, nil
}
func main() {
// init glfw
if err := glfw.Init(); err != nil {
panic(err)
}
defer glfw.Terminate()
glfw.WindowHint(glfw.Resizable, glfw.False)
glfw.WindowHint(glfw.ContextVersionMajor, 4)
glfw.WindowHint(glfw.ContextVersionMinor, 1)
glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
// make an application window
window, err := glfw.CreateWindow(windowWidth, windowHeight, "Transform", nil, nil)
if err != nil {
panic(err)
}
window.MakeContextCurrent()
// init gl
if err := gl.Init(); err != nil {
panic(err)
}
fmt.Println("OpenGL version", gl.GoStr(gl.GetString(gl.VERSION)))
// create vertex & fragment shader
program, err := newProgram(vertexShader, fragmentShader)
if err != nil {
panic(err)
}
gl.UseProgram(program)
projection := mgl32.Perspective(mgl32.DegToRad(45.0), float32(windowWidth)/windowHeight, 0.1, 10.0)
projectionUniform := gl.GetUniformLocation(program, gl.Str("projection\x00"))
gl.UniformMatrix4fv(projectionUniform, 1, false, &projection[0])
camera := mgl32.LookAtV(
mgl32.Vec3{3, 3, 3},
mgl32.Vec3{0, 0, 0},
mgl32.Vec3{0, 1, 0},
)
cameraUniform := gl.GetUniformLocation(program, gl.Str("camera\x00"))
gl.UniformMatrix4fv(cameraUniform, 1, false, &camera[0])
model := mgl32.Ident4()
modelUniform := gl.GetUniformLocation(program, gl.Str("model\x00"))
gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])
gl.BindFragDataLocation(program, 0, gl.Str("vert\x00"))
points := []float32{
-0.9, -0.9, -0.9,
0.9, -0.9, -0.9,
0.9, -0.9, 0.9,
-0.9, -0.9, 0.9,
-0.9, 0.9, -0.9,
0.9, 0.9, -0.9,
0.9, 0.9, 0.9,
-0.9, 0.9, 0.9,
}
vertices := []uint32{
0, 1,
1, 2,
2, 3,
3, 0,
0, 4,
1, 5,
2, 6,
3, 7,
4, 5,
5, 6,
6, 7,
7, 4,
}
// configure the vertex data
var vao uint32
gl.GenVertexArrays(1, &vao)
gl.BindVertexArray(vao)
defer gl.BindVertexArray(0)
var vbo uint32
gl.GenBuffers(1, &vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(points)*4, gl.Ptr(points), gl.STATIC_DRAW)
var ibo uint32
gl.GenBuffers(1, &ibo)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, ibo)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, len(vertices)*4, gl.Ptr(vertices), gl.STATIC_DRAW)
vertAttrib := uint32(gl.GetAttribLocation(program, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 3*4, gl.PtrOffset(0))
// global settings
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(0.0, 0.0, 0.0, 1.0)
angleX := 0.0
angleY := 0.0
angleZ := 0.0
previousTime := glfw.GetTime()
for !window.ShouldClose() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
time := glfw.GetTime()
elapsed := time - previousTime
previousTime = time
angleX += math.Sin((elapsed / period) * math.Pi * 2.0)
angleY += math.Sin((elapsed / period) / 6.0 * math.Pi * 2.0)
angleZ += math.Sin((elapsed / period) / 3.0 * math.Pi * 2.0)
model = mgl32.HomogRotate3DY(float32(angleY)).Mul4(mgl32.HomogRotate3DX(float32(angleX))).Mul4(mgl32.HomogRotate3DZ(float32(angleZ)))
gl.UseProgram(program)
gl.UniformMatrix4fv(modelUniform, 1, false, &model[0])
gl.BindVertexArray(vao)
gl.DrawElements(gl.LINES, int32(len(vertices)), gl.UNSIGNED_INT, gl.PtrOffset(0))
window.SwapBuffers()
glfw.PollEvents()
}
}
// CreateSphere generates a 3d uv-sphere with the given radius and returns a Renderable.
func CreateSphere(radius float32, rings int, sectors int) *Renderable {
// nothing to create
if rings < 2 || sectors < 2 {
return nil
}
const piDiv2 = math.Pi / 2.0
verts := make([]float32, 0, rings*sectors)
indexes := make([]uint32, 0, rings*sectors)
uvs := make([]float32, 0, rings*sectors)
normals := make([]float32, 0, rings*sectors)
R := float64(1.0 / float32(rings-1))
S := float64(1.0 / float32(sectors-1))
for ri := 0; ri < int(rings); ri++ {
for si := 0; si < int(sectors); si++ {
y := float32(math.Sin(-piDiv2 + math.Pi*float64(ri)*R))
x := float32(math.Cos(2.0*math.Pi*float64(si)*S) * math.Sin(math.Pi*float64(ri)*R))
z := float32(math.Sin(2.0*math.Pi*float64(si)*S) * math.Sin(math.Pi*float64(ri)*R))
uvs = append(uvs, float32(si)*float32(S))
uvs = append(uvs, float32(ri)*float32(R))
verts = append(verts, x*radius)
verts = append(verts, y*radius)
verts = append(verts, z*radius)
normals = append(normals, x)
normals = append(normals, y)
normals = append(normals, z)
currentRow := ri * sectors
nextRow := (ri + 1) * sectors
indexes = append(indexes, uint32(currentRow+si))
indexes = append(indexes, uint32(nextRow+si))
indexes = append(indexes, uint32(nextRow+si+1))
indexes = append(indexes, uint32(currentRow+si))
indexes = append(indexes, uint32(nextRow+si+1))
indexes = append(indexes, uint32(currentRow+si+1))
}
}
r := NewRenderable()
gl.GenVertexArrays(1, &r.Vao)
r.FaceCount = rings * sectors * 2
const floatSize = 4
const uintSize = 4
// create a VBO to hold the vertex data
gl.GenBuffers(1, &r.VertVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.VertVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(verts), gl.Ptr(&verts[0]), gl.STATIC_DRAW)
// create a VBO to hold the uv data
gl.GenBuffers(1, &r.UvVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.UvVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(uvs), gl.Ptr(&uvs[0]), gl.STATIC_DRAW)
// create a VBO to hold the normals data
gl.GenBuffers(1, &r.NormsVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.NormsVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(normals), gl.Ptr(&normals[0]), gl.STATIC_DRAW)
// create a VBO to hold the face indexes
gl.GenBuffers(1, &r.ElementsVBO)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.ElementsVBO)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, uintSize*len(indexes), gl.Ptr(&indexes[0]), gl.STATIC_DRAW)
return r
}
// CreateCube makes a new Renderable object with the specified dimensions for the cube.
func CreateCube(xmin, ymin, zmin, xmax, ymax, zmax float32) *Renderable {
/* Cube vertices are layed out like this:
+--------+ 6 5
/ | /|
+--------+ | 1 0 +Y
| | | | |___ +X
| +------|-+ 7 4 /
|/ |/ +Z
+--------+ 2 3
*/
verts := [...]float32{
xmax, ymax, zmax, xmin, ymax, zmax, xmin, ymin, zmax, xmax, ymin, zmax, // v0,v1,v2,v3 (front)
xmax, ymax, zmin, xmax, ymax, zmax, xmax, ymin, zmax, xmax, ymin, zmin, // v5,v0,v3,v4 (right)
xmax, ymax, zmin, xmin, ymax, zmin, xmin, ymax, zmax, xmax, ymax, zmax, // v5,v6,v1,v0 (top)
xmin, ymax, zmax, xmin, ymax, zmin, xmin, ymin, zmin, xmin, ymin, zmax, // v1,v6,v7,v2 (left)
xmax, ymin, zmax, xmin, ymin, zmax, xmin, ymin, zmin, xmax, ymin, zmin, // v3,v2,v7,v4 (bottom)
xmin, ymax, zmin, xmax, ymax, zmin, xmax, ymin, zmin, xmin, ymin, zmin, // v6,v5,v4,v7 (back)
}
indexes := [...]uint32{
0, 1, 2, 2, 3, 0,
4, 5, 6, 6, 7, 4,
8, 9, 10, 10, 11, 8,
12, 13, 14, 14, 15, 12,
16, 17, 18, 18, 19, 16,
20, 21, 22, 22, 23, 20,
}
uvs := [...]float32{
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0,
}
normals := [...]float32{
0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, // v0,v1,v2,v3 (front)
1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, // v5,v0,v3,v4 (right)
0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, // v5,v6,v1,v0 (top)
-1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, // v1,v6,v7,v2 (left)
0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, // v3,v2,v7,v4 (bottom)
0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, // v6,v5,v4,v7 (back)
}
r := NewRenderable()
gl.GenVertexArrays(1, &r.Vao)
r.FaceCount = 12
const floatSize = 4
const uintSize = 4
// create a VBO to hold the vertex data
gl.GenBuffers(1, &r.VertVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.VertVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(verts), gl.Ptr(&verts[0]), gl.STATIC_DRAW)
// create a VBO to hold the uv data
gl.GenBuffers(1, &r.UvVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.UvVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(uvs), gl.Ptr(&uvs[0]), gl.STATIC_DRAW)
// create a VBO to hold the normals data
gl.GenBuffers(1, &r.NormsVBO)
gl.BindBuffer(gl.ARRAY_BUFFER, r.NormsVBO)
gl.BufferData(gl.ARRAY_BUFFER, floatSize*len(normals), gl.Ptr(&normals[0]), gl.STATIC_DRAW)
// create a VBO to hold the face indexes
gl.GenBuffers(1, &r.ElementsVBO)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.ElementsVBO)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, uintSize*len(indexes), gl.Ptr(&indexes[0]), gl.STATIC_DRAW)
return r
}
// bindString generates all of the vertex buffers and vertex arrays for a single constant line of
// text. No error checking is done.
func (d *Dictionary) bindString(str string) strData {
var data strData
gl.GenVertexArrays(1, &data.varrays[0])
gl.BindVertexArray(data.varrays[0])
gl.GenBuffers(2, &data.vbuffers[0])
var positions, texcoords []float32
var pen pos
var prev rune
for _, r := range str {
ri := d.Runes[r]
var scale float32 = 1.0 / float32(d.GlyphMax.Dy())
var posMin, posMax pos
posMin.x = pen.x + float32(ri.GlyphBounds.Min.X)*scale
posMin.y = pen.y + float32(ri.GlyphBounds.Min.Y)*scale
posMax.x = pen.x + float32(ri.GlyphBounds.Max.X)*scale
posMax.y = pen.y + float32(ri.GlyphBounds.Max.Y)*scale
var texMin, texMax pos
texMin.x = float32(ri.PixBounds.Min.X) / float32(d.Dx)
texMin.y = float32(ri.PixBounds.Min.Y) / float32(d.Dy)
texMax.x = float32(ri.PixBounds.Max.X) / float32(d.Dx)
texMax.y = float32(ri.PixBounds.Max.Y) / float32(d.Dy)
pen.x += float32(ri.AdvanceWidth) * scale
pen.x += float32(d.Kerning[RunePair{prev, r}]) * scale
// pen.x -= float32(d.Kerning[RunePair{prev, r}]) * scale
positions = append(positions, posMin.x) // lower left
positions = append(positions, posMin.y)
positions = append(positions, posMin.x) // upper left
positions = append(positions, posMax.y)
positions = append(positions, posMax.x) // upper right
positions = append(positions, posMax.y)
positions = append(positions, posMin.x) // lower left
positions = append(positions, posMin.y)
positions = append(positions, posMax.x) // upper right
positions = append(positions, posMax.y)
positions = append(positions, posMax.x) // lower right
positions = append(positions, posMin.y)
texcoords = append(texcoords, texMin.x) // lower left
texcoords = append(texcoords, texMax.y)
texcoords = append(texcoords, texMin.x) // upper left
texcoords = append(texcoords, texMin.y)
texcoords = append(texcoords, texMax.x) // upper right
texcoords = append(texcoords, texMin.y)
texcoords = append(texcoords, texMin.x) // lower left
texcoords = append(texcoords, texMax.y)
texcoords = append(texcoords, texMax.x) // upper right
texcoords = append(texcoords, texMin.y)
texcoords = append(texcoords, texMax.x) // lower right
texcoords = append(texcoords, texMax.y)
prev = r
}
data.count = int32(len(positions))
gl.BindBuffer(gl.ARRAY_BUFFER, data.vbuffers[0])
gl.BufferData(gl.ARRAY_BUFFER, len(positions)*int(unsafe.Sizeof(positions[0])), gl.Ptr(&positions[0]), gl.STATIC_DRAW)
location, _ := render.GetAttribLocation("glop.font", "position")
gl.EnableVertexAttribArray(uint32(location))
gl.VertexAttribPointer(uint32(location), 2, gl.FLOAT, false, 0, gl.PtrOffset(0))
gl.BindBuffer(gl.ARRAY_BUFFER, data.vbuffers[1])
gl.BufferData(gl.ARRAY_BUFFER, len(texcoords)*int(unsafe.Sizeof(texcoords[0])), gl.Ptr(&texcoords[0]), gl.STATIC_DRAW)
location, _ = render.GetAttribLocation("glop.font", "texCoord")
gl.EnableVertexAttribArray(uint32(location))
gl.VertexAttribPointer(uint32(location), 2, gl.FLOAT, false, 0, gl.PtrOffset(0))
return data
}
