func (t *Text) Draw() {
if t.IsDebug {
t.BoundingBox.Draw()
}
gl.UseProgram(t.font.program)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, t.font.textureID)
// uniforms
gl.Uniform1i(t.font.fragmentTextureUniform, 0)
gl.Uniform4fv(t.font.colorUniform, 1, &t.color[0])
gl.Uniform2fv(t.font.finalPositionUniform, 1, &t.finalPosition[0])
gl.UniformMatrix4fv(t.font.orthographicMatrixUniform, 1, false, &t.font.OrthographicMatrix[0])
gl.UniformMatrix4fv(t.font.scaleMatrixUniform, 1, false, &t.scaleMatrix[0])
// draw
drawCount := int32(t.RuneCount * 6)
if drawCount > int32(t.eboIndexCount) {
drawCount = int32(t.eboIndexCount)
}
if drawCount < 0 {
drawCount = 0
}
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
gl.BindVertexArray(t.vao)
gl.DrawElements(gl.TRIANGLES, drawCount, gl.UNSIGNED_INT, nil)
gl.BindVertexArray(0)
gl.Disable(gl.BLEND)
}
func (lr *LinesRenderer) Draw(line *LineGeometry, mv mgl32.Mat4, style *LineStyle) (err error) {
var (
dataBytes int = len(line.Vertices) * int(lr.stride)
indexBytes int = len(line.Indices) * int(lr.stride)
elementCount int32 = int32(len(line.Indices))
r, g, b, a = style.Color.RGBA()
)
gl.Uniform1f(lr.thicknessLoc, style.Thickness)
gl.Uniform1f(lr.innerLoc, style.Inner)
gl.Uniform4f(lr.colorLoc, float32(r)/255.0, float32(g)/255.0, float32(b)/255.0, float32(a)/255.0)
gl.UniformMatrix4fv(lr.modelviewLoc, 1, false, &mv[0])
if dataBytes > lr.bufferBytes {
lr.bufferBytes = dataBytes
gl.BufferData(gl.ARRAY_BUFFER, dataBytes, gl.Ptr(line.Vertices), gl.STREAM_DRAW)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, indexBytes, gl.Ptr(line.Indices), gl.STREAM_DRAW)
} else {
gl.BufferSubData(gl.ARRAY_BUFFER, 0, dataBytes, gl.Ptr(line.Vertices))
gl.BufferSubData(gl.ELEMENT_ARRAY_BUFFER, 0, indexBytes, gl.Ptr(line.Indices))
}
gl.DrawElements(gl.TRIANGLES, elementCount, gl.UNSIGNED_INT, gl.PtrOffset(0))
if e := gl.GetError(); e != 0 {
err = fmt.Errorf("ERROR: OpenGL error %X", e)
}
return
}
// Rendering this LineRender.
func (lr *LineRender) Render() {
// Binding the appropriate information.
gl.BindVertexArray(lr.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, lr.vbo)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, lr.ebo)
gl.UseProgram(lr.shaderProgram)
// Loading up vertex attributes.
vertAttrib := uint32(gl.GetAttribLocation(lr.shaderProgram, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 2, gl.FLOAT, false, 2*4, gl.PtrOffset(0))
// Line thickness information.
gl.Uniform1f(
gl.GetUniformLocation(lr.shaderProgram, gl.Str("in_thickness\x00")),
lr.weight)
// Fragment shader color information.
gl.Uniform4f(
gl.GetUniformLocation(lr.shaderProgram, gl.Str("in_color\x00")),
lr.color.Red,
lr.color.Green,
lr.color.Blue,
lr.color.Alpha)
gl.BindFragDataLocation(lr.shaderProgram, 0, gl.Str("out_color\x00"))
// Performing the render.
gl.DrawElements(gl.LINE_STRIP, lr.points, gl.UNSIGNED_INT, nil)
}
func (b *BoundingBox) Draw() {
gl.UseProgram(b.program)
// uniforms
gl.Uniform2fv(b.finalPositionUniform, 1, &b.finalPosition[0])
gl.UniformMatrix4fv(b.orthographicMatrixUniform, 1, false, &b.font.OrthographicMatrix[0])
// draw
gl.BindVertexArray(b.vao)
gl.DrawElements(gl.TRIANGLES, int32(b.eboIndexCount), gl.UNSIGNED_INT, nil)
gl.BindVertexArray(0)
}
func (s *Sprite) Draw() {
s.shader.Use()
s.texture.Bind()
gl.BindVertexArray(s.vao)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, s.ebo)
gl.BindBuffer(gl.ARRAY_BUFFER, s.vbo)
//gl.DrawArrays(gl.TRIANGLES, 0, 3)
gl.DrawElements(gl.TRIANGLES, 6, gl.UNSIGNED_INT, gl.PtrOffset(0))
gl.BindVertexArray(0)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0)
}
func (renderObject *RenderObject) Render() {
gl.BindVertexArray(renderObject.vao)
gl.BindBuffer(gl.ARRAY_BUFFER, renderObject.vbo)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, renderObject.ebo)
gl.UseProgram(renderObject.shaderProgram)
// Binding the texture.
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, renderObject.texture)
gl.BindFragDataLocation(renderObject.shaderProgram, 0, gl.Str("outputColor\x00"))
// Drawing the object.
gl.DrawElements(gl.TRIANGLES, 6, gl.UNSIGNED_INT, 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, "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 (m *mesh) drawElements() {
gl.BindVertexArray(m.vao)
gl.DrawElements(gl.TRIANGLES, m.count, gl.UNSIGNED_SHORT, gl.Ptr(nil))
gl.BindVertexArray(0)
}
func (r *Renderable) Draw(perspective mgl.Mat4, view mgl.Mat4) {
gl.UseProgram(r.Shader)
gl.BindVertexArray(r.Vao)
model := r.GetTransformMat4()
var mvp mgl.Mat4
shaderMvp := getUniformLocation(r.Shader, "MVP_MATRIX")
if shaderMvp >= 0 {
mvp = perspective.Mul4(view).Mul4(model)
gl.UniformMatrix4fv(shaderMvp, 1, false, &mvp[0])
}
shaderMv := getUniformLocation(r.Shader, "MV_MATRIX")
if shaderMv >= 0 {
mv := view.Mul4(model)
gl.UniformMatrix4fv(shaderMv, 1, false, &mv[0])
}
shaderTex0 := getUniformLocation(r.Shader, "DIFFUSE_TEX")
if shaderTex0 >= 0 {
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, r.Tex0)
gl.Uniform1i(shaderTex0, 0)
}
shaderColor := getUniformLocation(r.Shader, "MATERIAL_DIFFUSE")
if shaderColor >= 0 {
gl.Uniform4f(shaderColor, r.Color[0], r.Color[1], r.Color[2], r.Color[3])
}
shaderTex1 := getUniformLocation(r.Shader, "MATERIAL_TEX_0")
if shaderTex1 >= 0 {
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, r.Tex0)
gl.Uniform1i(shaderTex1, 0)
}
shaderCameraWorldPos := getUniformLocation(r.Shader, "CAMERA_WORLD_POSITION")
if shaderCameraWorldPos >= 0 {
gl.Uniform3f(shaderCameraWorldPos, -view[12], -view[13], -view[14])
}
shaderPosition := getAttribLocation(r.Shader, "VERTEX_POSITION")
if shaderPosition >= 0 {
gl.BindBuffer(gl.ARRAY_BUFFER, r.VertVBO)
gl.EnableVertexAttribArray(uint32(shaderPosition))
gl.VertexAttribPointer(uint32(shaderPosition), 3, gl.FLOAT, false, 0, gl.PtrOffset(0))
}
shaderNormal := getAttribLocation(r.Shader, "VERTEX_NORMAL")
if shaderNormal >= 0 {
gl.BindBuffer(gl.ARRAY_BUFFER, r.NormsVBO)
gl.EnableVertexAttribArray(uint32(shaderNormal))
gl.VertexAttribPointer(uint32(shaderNormal), 3, gl.FLOAT, false, 0, gl.PtrOffset(0))
}
shaderVertUv := getAttribLocation(r.Shader, "VERTEX_UV_0")
if shaderVertUv >= 0 {
gl.BindBuffer(gl.ARRAY_BUFFER, r.UvVBO)
gl.EnableVertexAttribArray(uint32(shaderVertUv))
gl.VertexAttribPointer(uint32(shaderVertUv), 2, gl.FLOAT, false, 0, gl.PtrOffset(0))
}
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.ElementsVBO)
gl.DrawElements(gl.TRIANGLES, int32(r.FaceCount*3), gl.UNSIGNED_INT, gl.PtrOffset(0))
gl.BindVertexArray(0)
}
//DrawCall send a single draw call
func (m *VUNMesh) DrawCall() {
gl.DrawElements(gl.TRIANGLES, m.Size(), gl.UNSIGNED_SHORT, 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()
}
}
