func (cube *Cube) Draw() {
/* Bind cube vertices. Note that this is in attribute index 0 */
gl.BindBuffer(gl.ARRAY_BUFFER, cube.bufferObject)
gl.EnableVertexAttribArray(0)
gl.VertexAttribPointer(0, 3, gl.FLOAT, false, 0, nil)
/* Bind cube colours. Note that this is in attribute index 1 */
gl.BindBuffer(gl.ARRAY_BUFFER, cube.coloursObject)
gl.EnableVertexAttribArray(1)
gl.VertexAttribPointer(1, 4, gl.FLOAT, false, 0, nil)
/* Bind cube normals. Note that this is in attribute index 2 */
gl.EnableVertexAttribArray(2)
gl.BindBuffer(gl.ARRAY_BUFFER, cube.normalsObject)
gl.VertexAttribPointer(2, 3, gl.FLOAT, false, 0, nil)
// Enable this line to show model in wireframe
if cube.DrawMode == DRAW_LINES {
gl.PolygonMode(gl.FRONT_AND_BACK, gl.LINE)
} else {
gl.PolygonMode(gl.FRONT_AND_BACK, gl.FILL)
}
/* Draw our cube*/
if cube.DrawMode == DRAW_POINTS {
gl.DrawArrays(gl.POINTS, 0, int32(32))
} else {
gl.DrawArrays(gl.TRIANGLES, 0, 36)
}
}
// Draws the sphere form the previously defined vertex and index buffers
func (sphere *Sphere) Draw() {
// Adds the Sphere Model to the Active Shader
sphere.ShaderManager.SetUniformMatrix4fv(sphere.ShaderManager.ActiveShader, "model", 1, false, &sphere.Model[0])
/* Draw the vertices as GL_POINTS */
gl.BindBuffer(gl.ARRAY_BUFFER, sphere.sphereBufferObject)
gl.VertexAttribPointer(0, 3, gl.FLOAT, false, 0, nil)
gl.EnableVertexAttribArray(0)
/* Bind the sphere colours */
gl.BindBuffer(gl.ARRAY_BUFFER, sphere.sphereColours)
gl.VertexAttribPointer(1, 4, gl.FLOAT, false, 0, nil)
gl.EnableVertexAttribArray(1)
/* Bind the sphere normals */
gl.BindBuffer(gl.ARRAY_BUFFER, sphere.sphereNormals)
gl.VertexAttribPointer(2, 3, gl.FLOAT, false, 0, nil)
gl.EnableVertexAttribArray(2)
gl.PointSize(3.0)
// Enable this line to show model in wireframe
if sphere.DrawMode == DRAW_LINES {
gl.PolygonMode(gl.FRONT_AND_BACK, gl.LINE)
} else {
gl.PolygonMode(gl.FRONT_AND_BACK, gl.FILL)
}
if sphere.DrawMode == DRAW_POINTS {
gl.DrawArrays(gl.POINTS, 0, int32(sphere.numSphereVertices))
} else {
/* Bind the indexed vertex buffer */
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, sphere.elementBuffer)
/* Draw the north pole regions as a triangle */
gl.DrawElements(gl.TRIANGLE_FAN, int32(sphere.numLongs+2), gl.UNSIGNED_INT, nil)
/* Calculate offsets into the indexed array. Note that we multiply offsets by 4
because it is a memory offset the indices are type GLuint which is 4-bytes */
var lat_offset_jump int = int((sphere.numLongs * 2) + 2)
var lat_offset_start int = int(sphere.numLongs + 2)
var lat_offset_current int = lat_offset_start * 4
var i uint32
/* Draw the triangle strips of latitudes */
for i = 0; i < sphere.numLats-2; i++ {
gl.DrawElements(gl.TRIANGLE_STRIP, int32(sphere.numLongs*2+2), gl.UNSIGNED_INT, gl.PtrOffset(lat_offset_current))
lat_offset_current += (lat_offset_jump * 4)
}
/* Draw the south pole as a triangle fan */
gl.DrawElements(gl.TRIANGLE_FAN, int32(sphere.numLongs+2), gl.UNSIGNED_INT, gl.PtrOffset(lat_offset_current))
}
}
// Draws the cog form the previously defined vertex and index buffers
func (cog *Cog) Draw() {
// Adds the Sphere Model to the Active Shader
cog.ShaderManager.SetUniformMatrix4fv(cog.ShaderManager.ActiveShader, "model", 1, false, &cog.Model[0])
/* Draw the vertices as GL_POINTS */
gl.BindBuffer(gl.ARRAY_BUFFER, cog.cogBufferObject)
gl.VertexAttribPointer(0, 3, gl.FLOAT, false, 0, nil)
gl.EnableVertexAttribArray(0)
/* Bind the sphere colours */
gl.BindBuffer(gl.ARRAY_BUFFER, cog.cogColours)
gl.VertexAttribPointer(1, 4, gl.FLOAT, false, 0, nil)
gl.EnableVertexAttribArray(1)
/* Bind the sphere normals */
gl.BindBuffer(gl.ARRAY_BUFFER, cog.cogNormals)
gl.VertexAttribPointer(2, 3, gl.FLOAT, false, 0, nil)
gl.EnableVertexAttribArray(2)
gl.PointSize(3.0)
// Enable this line to show model in wireframe
if cog.DrawMode == DRAW_LINES {
gl.PolygonMode(gl.FRONT_AND_BACK, gl.LINE)
} else {
gl.PolygonMode(gl.FRONT_AND_BACK, gl.FILL)
}
if cog.DrawMode == DRAW_POINTS {
gl.DrawArrays(gl.POINTS, 0, int32(cog.numCogVertices))
} else {
// Bind the indexed vertex buffer
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, cog.elementBuffer)
// Draw the north pole regions as a triangle
gl.DrawElements(gl.TRIANGLE_FAN, int32(cog.VerticesPerDisk+2), gl.UNSIGNED_INT, nil)
// Calculate offsets into the indexed array. Note that we multiply offsets by 4
// because it is a memory offset the indices are type GLuint which is 4-bytes
var lat_offset_jump int = int((cog.VerticesPerDisk * 2) + 2)
var lat_offset_start int = int(cog.VerticesPerDisk + 2)
var lat_offset_current int = lat_offset_start * 4
// Draw the triangle strips of Sides
gl.DrawElements(gl.TRIANGLE_STRIP, int32(cog.VerticesPerDisk*2+2), gl.UNSIGNED_INT, gl.PtrOffset(lat_offset_current))
lat_offset_current += (lat_offset_jump * 4)
// Draw the south pole as a triangle fan
gl.DrawElements(gl.TRIANGLE_FAN, int32(cog.VerticesPerDisk+2), gl.UNSIGNED_INT, gl.PtrOffset(lat_offset_current))
}
}
//
// Copy the vertices, normals and element indices into vertex buffers
//
func (terrain *Terrain) CreateObject() {
// Generate the vertex buffer object
gl.GenBuffers(1, &terrain.VBOVertices)
gl.BindBuffer(gl.ARRAY_BUFFER, terrain.VBOVertices)
gl.BufferData(gl.ARRAY_BUFFER, int(len(terrain.Vertices)*3*4), gl.Ptr(terrain.Vertices), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
/* Store the normals in a buffer object */
gl.GenBuffers(1, &terrain.VBONormals)
gl.BindBuffer(gl.ARRAY_BUFFER, terrain.VBONormals)
gl.BufferData(gl.ARRAY_BUFFER, int(len(terrain.Normals)*3*4), gl.Ptr(terrain.Normals), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
/* Store the Colors in a buffer object */
gl.GenBuffers(1, &terrain.VBOColors)
gl.BindBuffer(gl.ARRAY_BUFFER, terrain.VBOColors)
gl.BufferData(gl.ARRAY_BUFFER, int(len(terrain.Colors)*5*4), gl.Ptr(terrain.Colors), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
// Generate a buffer for the indices
gl.GenBuffers(1, &terrain.VBOIndices)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, terrain.VBOIndices)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, int(len(terrain.Indices)*SizeOfUint16), gl.Ptr(terrain.Indices), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
}
func render(w *glfw.Window, r *gResources) {
/*
width, height := w.GetFramebufferSize()
gl.Viewport(0, 0, int32(width), int32(height))
gl.Clear(gl.COLOR_BUFFER_BIT)
gl.MatrixMode(gl.PROJECTION)
gl.LoadIdentity()
gl.MatrixMode(gl.MODELVIEW)
gl.LoadIdentity()
*/
////////////////
gl.UseProgram(r.program)
gl.Uniform1f(r.uniforms.fadeFactor, r.fadeFactor)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, r.textures[0])
gl.Uniform1i(r.uniforms.textures[0], 0)
gl.ActiveTexture(gl.TEXTURE1)
gl.BindTexture(gl.TEXTURE_2D, r.textures[1])
gl.Uniform1i(r.uniforms.textures[1], 1)
gl.BindBuffer(gl.ARRAY_BUFFER, r.vertexBuffer)
gl.VertexAttribPointer(
uint32(r.attributes.position), /* attribute */
2, /* size */
gl.FLOAT, /* type */
false, /* normalized? */
8, /* stride */
gl.PtrOffset(0)) /* array buffer offset */
gl.EnableVertexAttribArray(uint32(r.attributes.position))
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.elementBuffer)
gl.DrawElements(
gl.TRIANGLE_STRIP, /* mode */
4, /* count */
gl.UNSIGNED_INT, /* type */
gl.PtrOffset(0)) /* element array buffer offset */
gl.DisableVertexAttribArray(uint32(r.attributes.position))
}
func makeBuffer(target uint32, bufferData unsafe.Pointer, bufferSize int) uint32 {
var buffer uint32
gl.GenBuffers(1, &buffer)
gl.BindBuffer(target, buffer)
gl.BufferData(target, bufferSize, bufferData, gl.STATIC_DRAW)
return buffer
}
func CreateMesh(verticies []float32, texturePaths []string, shader *Shader) (*Mesh, error) {
modelView := mgl32.Ident4()
// // Load the texture
textures := make([]uint32, 0)
// fmt.Println(texturePaths)
for _, texturePath := range texturePaths {
// fmt.Println("Paths", texturePath, texturePaths[i])
texture, err := createTexture(texturePath)
if err != nil {
return nil, err
}
textures = append(textures, texture)
}
//
// // Configure the vertex data
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(verticies)*4, gl.Ptr(verticies), gl.STATIC_DRAW)
//
gl.EnableVertexAttribArray(shader.attributes["vert"])
gl.VertexAttribPointer(shader.attributes["vert"], 3, gl.FLOAT, false, 5*4, gl.PtrOffset(0))
//
gl.EnableVertexAttribArray(shader.attributes["vertTexCoord"])
gl.VertexAttribPointer(shader.attributes["vertTexCoord"], 2, gl.FLOAT, false, 5*4, gl.PtrOffset(3*4))
gl.BindVertexArray(0)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
return &Mesh{
modelView: modelView,
textures: textures,
verticies: verticies,
vao: vao,
vbo: vbo,
}, nil
}
func (glr *GlRenderer) initScreen() {
var err error
glr.program, err = createScreenShader()
if err != nil {
panic(err)
}
gl.UseProgram(glr.program)
projection := mgl32.Ortho2D(-1, 1, 1, -1)
projectionUniform := gl.GetUniformLocation(glr.program, gl.Str("projection\x00"))
gl.UniformMatrix4fv(projectionUniform, 1, false, &projection[0])
textureUniform := gl.GetUniformLocation(glr.program, gl.Str("tex\x00"))
gl.Uniform1i(textureUniform, 0)
glr.texture = createScreenTexture(glr.width, glr.height)
gl.GenVertexArrays(1, &glr.vao)
gl.BindVertexArray(glr.vao)
var quadVertices = []float32{
// X, Y, Z, U, V
1.0, -1.0, 0.0, 1.0, 0.0,
-1.0, -1.0, 0.0, 0.0, 0.0,
1.0, 1.0, 0.0, 1.0, 1.0,
-1.0, -1.0, 0.0, 0.0, 0.0,
-1.0, 1.0, 0.0, 0.0, 1.0,
1.0, 1.0, 0.0, 1.0, 1.0,
}
var vbo uint32
gl.GenBuffers(1, &vbo)
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
gl.BufferData(gl.ARRAY_BUFFER, len(quadVertices)*4, gl.Ptr(quadVertices), gl.STATIC_DRAW)
vertAttrib := uint32(gl.GetAttribLocation(glr.program, gl.Str("vert\x00")))
gl.EnableVertexAttribArray(vertAttrib)
gl.VertexAttribPointer(vertAttrib, 3, gl.FLOAT, false, 5*4, gl.PtrOffset(0))
texCoordAttrib := uint32(gl.GetAttribLocation(glr.program, gl.Str("vertTexCoord\x00")))
gl.EnableVertexAttribArray(texCoordAttrib)
gl.VertexAttribPointer(texCoordAttrib, 2, gl.FLOAT, false, 5*4, gl.PtrOffset(3*4))
gl.Enable(gl.DEPTH_TEST)
gl.ClearColor(1.0, 1.0, 1.0, 1.0)
}
func (objectLoader *WavefrontObject) CreateObject() {
for _, object := range objectLoader.Objects {
// Sets the Model in the Initial position
object.Model = mgl32.Ident4()
if wrapper.DEBUG {
// Print the object
fmt.Println(object)
}
// Generate the vertex buffer object
gl.GenBuffers(1, &object.VertexBufferObjectVertices)
gl.BindBuffer(gl.ARRAY_BUFFER, object.VertexBufferObjectVertices)
gl.BufferData(gl.ARRAY_BUFFER, int(len(object.Vertex)*4), gl.Ptr(&(object.Vertex[0])), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
// Obj might not have normals
if len(object.Normals) != 0 {
// Store the normals in a buffer object
gl.GenBuffers(1, &object.VertexBufferObjectNormals)
gl.BindBuffer(gl.ARRAY_BUFFER, object.VertexBufferObjectNormals)
gl.BufferData(gl.ARRAY_BUFFER, int(len(object.Normals)*4), gl.Ptr(&(object.Normals[0])), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
}
// Generate a buffer for the indices
gl.GenBuffers(1, &object.VertexBufferObjectFaces)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, object.VertexBufferObjectFaces)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, int(len(object.Faces)*3), gl.Ptr(&(object.Faces[0])), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
if len(object.Coordinates) != 0 {
// Generate a buffer for the Texture Coordinates
gl.GenBuffers(1, &object.VertexBufferObjectTextureCoords)
gl.BindBuffer(gl.ARRAY_BUFFER, object.VertexBufferObjectTextureCoords)
gl.BufferData(gl.ARRAY_BUFFER, int(len(object.Coordinates)*2)*2, gl.Ptr(&(object.Coordinates[0])), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
}
}
}
func (cube *Cube) MakeVBO() {
// Create a vertex buffer object to store vertices for the cube
gl.GenBuffers(1, &cube.bufferObject)
gl.BindBuffer(gl.ARRAY_BUFFER, cube.bufferObject)
gl.BufferData(gl.ARRAY_BUFFER, len(*cube.vertexPositions)*4, gl.Ptr(*cube.vertexPositions), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
// Create a vertex buffer object to store vertex colours for the cube
gl.GenBuffers(1, &cube.coloursObject)
gl.BindBuffer(gl.ARRAY_BUFFER, cube.coloursObject)
gl.BufferData(gl.ARRAY_BUFFER, len(*cube.vertexColours)*4, gl.Ptr(*cube.vertexColours), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
// Create the normals buffer for the cube
gl.GenBuffers(1, &cube.normalsObject)
gl.BindBuffer(gl.ARRAY_BUFFER, cube.normalsObject)
gl.BufferData(gl.ARRAY_BUFFER, len(*cube.normals)*4, gl.Ptr(*cube.normals), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
}
func (objectLoader *WavefrontObject) DrawObject(shaderProgram uint32) {
for _, object := range objectLoader.Objects {
// Reads the uniform Locations
modelUniform := gl.GetUniformLocation(shaderProgram, gl.Str("model\x00"))
ambientUniform := gl.GetUniformLocation(shaderProgram, gl.Str("ambient\x00"))
diffuseUniform := gl.GetUniformLocation(shaderProgram, gl.Str("diffuse\x00"))
specularUniform := gl.GetUniformLocation(shaderProgram, gl.Str("specular\x00"))
emissiveUniform := gl.GetUniformLocation(shaderProgram, gl.Str("emissive\x00"))
// Send our uniforms variables to the currently bound shader
if object.Material != nil {
gl.Uniform4f(ambientUniform, object.Material.KaR, object.Material.KaG, object.Material.KaB, object.Material.Tr) // Ambient colour.
gl.Uniform4f(diffuseUniform, object.Material.KdR, object.Material.KdG, object.Material.KdB, object.Material.Tr) // Diffuse colour.
gl.Uniform4f(specularUniform, object.Material.KsR, object.Material.KsG, object.Material.KsB, object.Material.Tr) // Specular colour.
gl.Uniform4f(emissiveUniform, object.Material.KeR, object.Material.KeG, object.Material.KeB, object.Material.Tr) // Emissive colour.
if object.Material.Texture != 0 {
textureUniform := gl.GetUniformLocation(shaderProgram, gl.Str("DiffuseTextureSampler\x00"))
gl.Uniform1i(textureUniform, 0)
normalTextureUniform := gl.GetUniformLocation(shaderProgram, gl.Str("NormalTextureSampler\x00"))
gl.Uniform1i(normalTextureUniform, 1)
specularTextureUniform := gl.GetUniformLocation(shaderProgram, gl.Str("SpecularTextureSampler\x00"))
gl.Uniform1i(specularTextureUniform, 2)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, object.Material.Texture)
gl.ActiveTexture(gl.TEXTURE1)
gl.BindTexture(gl.TEXTURE_2D, object.Material.NormalMap)
gl.ActiveTexture(gl.TEXTURE2)
gl.BindTexture(gl.TEXTURE_2D, object.Material.SpecularMap)
}
if object.Material.Tr < 1.0 {
// Enables Transparencies
gl.Enable(gl.BLEND)
// gl.BlendFunc(gl.SRC_COLOR, gl.ONE)
// gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
}
}
// Geometry
var size int32 // Used to get the byte size of the element (vertex index) array
gl.UniformMatrix4fv(modelUniform, 1, false, &object.Model[0])
// Get the vertices uniform position
verticesUniform := uint32(gl.GetAttribLocation(shaderProgram, gl.Str("position\x00")))
normalsUniform := uint32(gl.GetAttribLocation(shaderProgram, gl.Str("normal\x00")))
textureCoordinatesUniform := uint32(gl.GetAttribLocation(shaderProgram, gl.Str("texcoord\x00")))
// Describe our vertices array to OpenGL (it can't guess its format automatically)
gl.BindBuffer(gl.ARRAY_BUFFER, object.VertexBufferObjectVertices)
gl.VertexAttribPointer(
verticesUniform, // attribute index
3, // number of elements per vertex, here (x,y,z)
gl.FLOAT, // the type of each element
false, // take our values as-is
0, // no extra data between each position
nil, // offset of first element
)
gl.EnableVertexAttribArray(normalsUniform)
gl.BindBuffer(gl.ARRAY_BUFFER, object.VertexBufferObjectNormals)
gl.VertexAttribPointer(
normalsUniform, // attribute
3, // number of elements per vertex, here (x,y,z)
gl.FLOAT, // the type of each element
false, // take our values as-is
0, // no extra data between each position
nil, // offset of first element
)
gl.EnableVertexAttribArray(textureCoordinatesUniform)
gl.BindBuffer(gl.ARRAY_BUFFER, object.VertexBufferObjectTextureCoords)
gl.VertexAttribPointer(
textureCoordinatesUniform, // attribute
2, // number of elements per vertex, here (u,v)
gl.FLOAT, // the type of each element
false, // take our values as-is
0, // no extra data between each position
nil, // offset of first element
)
size = int32(len(object.Vertex))
gl.PointSize(3.0)
// Enable this line to show model in wireframe
switch objectLoader.DrawMode {
case 1:
gl.PolygonMode(gl.FRONT_AND_BACK, gl.LINE)
default:
gl.PolygonMode(gl.FRONT_AND_BACK, gl.FILL)
}
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, object.VertexBufferObjectFaces)
gl.GetBufferParameteriv(gl.ELEMENT_ARRAY_BUFFER, gl.BUFFER_SIZE, &size)
gl.DrawElements(gl.TRIANGLES, int32(len(object.Faces)), gl.UNSIGNED_SHORT, nil)
// gl.DrawElements(gl.POINTS, int32(len(object.Faces)), gl.UNSIGNED_SHORT, nil)
// Disables transparencies
gl.Disable(gl.BLEND)
}
}
// Make a sphere from two triangle fans (one at each pole) and triangle strips along latitudes
// This version uses indexed vertex buffers for both the fans at the poles and the latitude strips
func (sphere *Sphere) MakeSphereVBO() {
var i uint32
// Calculate the number of vertices required in sphere
sphere.numSphereVertices = 2 + ((sphere.numLats - 1) * sphere.numLongs)
pColours := make([]float32, (sphere.numSphereVertices * 4))
pVertices, pNormals := sphere.MakeUnitSphere()
// Define colours as the x,y,z components of the sphere vertices
for i = 0; i < sphere.numSphereVertices; i++ {
pColours[i*4] = pVertices[i*3]
pColours[i*4+1] = pVertices[i*3+1]
pColours[i*4+2] = pVertices[i*3+2]
pColours[i*4+3] = 1.0
}
/* Generate the vertex buffer object */
gl.GenBuffers(1, &sphere.sphereBufferObject)
gl.BindBuffer(gl.ARRAY_BUFFER, sphere.sphereBufferObject)
gl.BufferData(gl.ARRAY_BUFFER, int(4*sphere.numSphereVertices*3), gl.Ptr(pVertices), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
/* Store the normals in a buffer object */
gl.GenBuffers(1, &sphere.sphereNormals)
gl.BindBuffer(gl.ARRAY_BUFFER, sphere.sphereNormals)
gl.BufferData(gl.ARRAY_BUFFER, int(4*sphere.numSphereVertices*3), gl.Ptr(pNormals), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
/* Store the colours in a buffer object */
gl.GenBuffers(1, &sphere.sphereColours)
gl.BindBuffer(gl.ARRAY_BUFFER, sphere.sphereColours)
gl.BufferData(gl.ARRAY_BUFFER, int(4*sphere.numSphereVertices*4), gl.Ptr(pColours), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
/* Calculate the number of indices in our index array and allocate memory for it */
numIndices := ((sphere.numLongs*2)+2)*(sphere.numLats-1) + ((sphere.numLongs + 2) * 2)
pIndices := make([]uint32, numIndices)
// fill "indices" to define triangle strips
var index int = 0 // Current index
// Define indices for the first triangle fan for one pole
for i = 0; i < sphere.numLongs+1; i++ {
pIndices[index] = i
index++
}
pIndices[index] = 1 // Join last triangle in the triangle fan
index++
var j uint32
var start uint32 = 1 // Start index for each latitude row
for j = 0; j < sphere.numLats-2; j++ {
for i = 0; i < sphere.numLongs; i++ {
pIndices[index] = start + i
index++
pIndices[index] = start + i + sphere.numLongs
index++
}
// close the triangle strip loop by going back to the first vertex in the loop
pIndices[index] = start
index++
// close the triangle strip loop by going back to the first vertex in the loop
pIndices[index] = start + sphere.numLongs
index++
start += sphere.numLongs
}
// Define indices for the last triangle fan for the south pole region
for i = sphere.numSphereVertices - 1; i > sphere.numSphereVertices-sphere.numLongs-2; i-- {
pIndices[index] = i
index++
}
pIndices[index] = sphere.numSphereVertices - 2 // Tie up last triangle in fan
index++
// Generate a buffer for the indices
gl.GenBuffers(1, &sphere.elementBuffer)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, sphere.elementBuffer)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, int(numIndices*4), gl.Ptr(pIndices), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
}
func (cog *Cog) MakeCogVBO() {
var i uint32
// Calculate the number of vertices required in sphere
cog.numCogVertices = ((cog.VerticesPerDisk + 2) * 4)
pVertices, pNormals := cog.MakeUnitcog()
pColours := make([]float32, ((cog.VerticesPerDisk * 4) * 4))
// Define colours as the x,y,z components of the cog vertices
for i = 0; i < (cog.VerticesPerDisk * 4); i++ {
pColours[i*4] = 0.3 + pVertices[i*2]
pColours[i*4+1] = 0.5 + pVertices[i*2+1]
pColours[i*4+2] = 0.3 + pVertices[i*2+2]
pColours[i*4+3] = 1.0
}
/* Generate the vertex buffer object */
gl.GenBuffers(1, &cog.cogBufferObject)
gl.BindBuffer(gl.ARRAY_BUFFER, cog.cogBufferObject)
gl.BufferData(gl.ARRAY_BUFFER, int(8*len(pVertices)*3), gl.Ptr(pVertices), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
/* Store the normals in a buffer object */
gl.GenBuffers(1, &cog.cogNormals)
gl.BindBuffer(gl.ARRAY_BUFFER, cog.cogNormals)
gl.BufferData(gl.ARRAY_BUFFER, int(8*len(pNormals)*3), gl.Ptr(pNormals), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
/* Store the colours in a buffer object */
gl.GenBuffers(1, &cog.cogColours)
gl.BindBuffer(gl.ARRAY_BUFFER, cog.cogColours)
gl.BufferData(gl.ARRAY_BUFFER, int(8*len(pColours)*4), gl.Ptr(pColours), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
/* Calculate the number of indices in our index array and allocate memory for it */
numIndices := (2 * (cog.VerticesPerDisk + 4)) * 2
pIndices := make([]uint32, numIndices)
// fill "indices" to define triangle strips
var index int = 0 // Current index
// Define indices for the first triangle fan for one pole
for i = 0; i < cog.VerticesPerDisk+1; i++ {
pIndices[index] = i
index++
}
// Join last triangle in the triangle fan
pIndices[index] = 1
index++
// Creates the Sides
for i = 1; i < (cog.VerticesPerDisk*2)+1; i++ {
pIndices[index] = i + cog.VerticesPerDisk
index++
}
// Join last triangle in the triangle fan
pIndices[index] = 1 + cog.VerticesPerDisk
index++
// Define indices for the last triangle fan for the south pole region
// Start on a corner to avoid breaking the model
pIndices[index] = ((cog.VerticesPerDisk + 3) - 2) + (cog.VerticesPerDisk * 3)
index++
// Go to Center and keep lopping till the end
for i = (cog.VerticesPerDisk + 3) - 1; i >= 1; i-- {
pIndices[index] = i + (cog.VerticesPerDisk * 3)
index++
}
// Generate a buffer for the indices
gl.GenBuffers(1, &cog.elementBuffer)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, cog.elementBuffer)
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, int(numIndices*4), gl.Ptr(pIndices), gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, 0)
}
func render(w *glfw.Window, r *gResources) {
width, height := w.GetFramebufferSize()
ratio := float32(width) / float32(height)
var xmul, ymul float32
if ratio > 1 {
xmul, ymul = ra/ratio, ra
} else {
xmul, ymul = ra, ra*ratio
}
d := time.Since(start).Seconds()
sin := float32(math.Sin(d))
cos := float32(math.Cos(d))
gl.Viewport(0, 0, int32(width), int32(height))
gl.Clear(gl.COLOR_BUFFER_BIT)
////////////////
// axes
gl.UseProgram(r.program1)
gl.BindBuffer(gl.ARRAY_BUFFER, r.vertexBuffer1)
gl.VertexAttribPointer(
uint32(r.attributes1.position), // attribute
2, // size
gl.FLOAT, // type
false, // normalized?
8, // stride
gl.PtrOffset(0)) // array buffer offset
gl.EnableVertexAttribArray(uint32(r.attributes1.position))
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.elementBuffer1)
gl.LineWidth(1)
gl.DrawElements(
gl.LINES, // mode
4, // count
gl.UNSIGNED_INT, // type
gl.PtrOffset(0)) // element array buffer offset
gl.DisableVertexAttribArray(uint32(r.attributes1.position))
////////////////
// triangle
gl.UseProgram(r.program2)
gl.Uniform1f(r.uniforms2.xmul, xmul)
gl.Uniform1f(r.uniforms2.ymul, ymul)
gl.Uniform1f(r.uniforms2.sin, sin)
gl.Uniform1f(r.uniforms2.cos, cos)
gl.BindBuffer(gl.ARRAY_BUFFER, r.vertexBuffer2)
gl.VertexAttribPointer(
uint32(r.attributes2.position), // attribute
2, // size
gl.FLOAT, // type
false, // normalized?
8, // stride
gl.PtrOffset(0)) // array buffer offset
gl.EnableVertexAttribArray(uint32(r.attributes2.position))
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.elementBuffer2)
gl.EnableVertexAttribArray(uint32(r.attributes2.color))
gl.BindBuffer(gl.ARRAY_BUFFER, r.colorBuffer2)
gl.VertexAttribPointer(
uint32(r.attributes2.color), // attribute
3, // size
gl.FLOAT, // type
false, // normalized?
0, // stride
gl.PtrOffset(0)) // array buffer offset
gl.DrawElements(
gl.TRIANGLES, // mode
3, // count
gl.UNSIGNED_INT, // type
gl.PtrOffset(0)) // element array buffer offset
////////////////
// circle
gl.BindBuffer(gl.ARRAY_BUFFER, r.vertexBuffer3)
gl.VertexAttribPointer(
uint32(r.attributes2.position), // attribute
2, // size
gl.FLOAT, // type
false, // normalized?
8, // stride
gl.PtrOffset(0)) // array buffer offset
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, r.elementBuffer3)
gl.BindBuffer(gl.ARRAY_BUFFER, r.colorBuffer3)
gl.VertexAttribPointer(
uint32(r.attributes2.color), // attribute
3, // size
gl.FLOAT, // type
false, // normalized?
0, // stride
gl.PtrOffset(0)) // array buffer offset
gl.LineWidth(5)
gl.DrawElements(
gl.LINE_LOOP, // mode
r.len3, // count
gl.UNSIGNED_INT, // type
gl.PtrOffset(0)) // element array buffer offset
gl.DisableVertexAttribArray(uint32(r.attributes2.color))
gl.DisableVertexAttribArray(uint32(r.attributes2.position))
}
/* Enable vertex attributes and draw object
Could improve efficiency by moving the vertex attribute pointer functions to the
create object but this method is more general
This code is almost untouched fomr the tutorial code except that I changed the
number of elements per vertex from 4 to 3*/
func (terrain *Terrain) DrawObject(shaderProgram uint32) {
toneUniform := gl.GetAttribLocation(shaderProgram, gl.Str("tone\x00"))
gl.Uniform4f(toneUniform, terrain.ColorTone.X(), terrain.ColorTone.Y(), terrain.ColorTone.Z(), terrain.ColorTone.W())
// gl.Uniform4f(toneUniform, 0.0, 1.0, 0.5, 1.0)
// gl.Uniform4fv(toneUniform, 1, &terrain.ColorTone[0])
// Reads the uniform Locations
modelUniform := gl.GetUniformLocation(shaderProgram, gl.Str("model\x00"))
// Send our uniforms variables to the currently bound shader
gl.UniformMatrix4fv(modelUniform, 1, false, &terrain.Model[0])
// Get the vertices uniform position
verticesUniform := uint32(gl.GetAttribLocation(shaderProgram, gl.Str("position\x00")))
normalsUniform := uint32(gl.GetAttribLocation(shaderProgram, gl.Str("normal\x00")))
colorsUniform := uint32(gl.GetAttribLocation(shaderProgram, gl.Str("colour\x00")))
// Describe our vertices array to OpenGL (it can't guess its format automatically)
gl.EnableVertexAttribArray(verticesUniform)
gl.BindBuffer(gl.ARRAY_BUFFER, terrain.VBOVertices)
gl.VertexAttribPointer(
verticesUniform, // attribute index
3, // number of elements per vertex, here (x,y,z)
gl.FLOAT, // the type of each element
false, // take our values as-is
0, // no extra data between each position
nil, // offset of first element
)
gl.EnableVertexAttribArray(normalsUniform)
gl.BindBuffer(gl.ARRAY_BUFFER, terrain.VBONormals)
gl.VertexAttribPointer(
normalsUniform, // attribute
3, // number of elements per vertex, here (x,y,z)
gl.FLOAT, // the type of each element
false, // take our values as-is
0, // no extra data between each position
nil, // offset of first element
)
gl.EnableVertexAttribArray(colorsUniform)
gl.BindBuffer(gl.ARRAY_BUFFER, terrain.VBOColors)
gl.VertexAttribPointer(
colorsUniform, // attribute
3, // number of elements per vertex, here (x,y,z)
gl.FLOAT, // the type of each element
false, // take our values as-is
0, // no extra data between each position
nil, // offset of first element
)
size := int32(len(terrain.Indices))
gl.PointSize(3.0)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, terrain.VBOIndices)
gl.GetBufferParameteriv(gl.ELEMENT_ARRAY_BUFFER, gl.BUFFER_SIZE, &size)
// Enable this line to show model in wireframe
switch terrain.DrawMode {
case 1:
gl.PolygonMode(gl.FRONT_AND_BACK, gl.LINE)
case 2:
gl.DrawArrays(gl.POINTS, 0, int32(len(terrain.Vertices)))
// gl.DrawElements(gl.POINTS, int32(len(terrain.Indices)), gl.UNSIGNED_SHORT, nil)
return
default:
gl.PolygonMode(gl.FRONT_AND_BACK, gl.FILL)
}
var location int = 0
/* Draw the triangle strips */
for i := uint32(0); i < terrain.XSize-1; i++ {
location = SizeOfUint16 * int(i*terrain.ZSize*2)
gl.DrawElements(gl.TRIANGLE_STRIP, int32(terrain.ZSize*2), gl.UNSIGNED_SHORT, gl.PtrOffset(location))
}
// gl.DrawElements(
// gl.TRIANGLE_STRIP,
// len(terrain.Indices),
// gl.UNSIGNED_SHORT,
// nil,
// )
}