// Pointer defines an array of generic vertex attribute data.
func (l VertexAttribArray) Pointer(sz int, t DataType, norm bool, stride, offs int) {
n := 0
if norm {
n = 1
}
C.glVertexAttribPointer(C.GLuint(l), C.GLint(sz), C.GLenum(t), C.GLboolean(n), C.GLsizei(stride), unsafe.Pointer(uintptr(offs)))
}
// VertexAttribSlice uses glVertexAttribPointer to bind an element of the currently
// bound buffer at the given index. In order to be able to determine the layout of
// the buffer, you need to pass in an uninitialized element of the slice used to fill
// the buffer. If dummy is a struct, the value you pass as dummy_index determines
// which member of dummy to bind at attribute index.
//
// e.g.,
//
// VertexAttribSlice(1, false, int32(0), 0)
//
// to bind an int32 slice to attrib 1, or,
//
// VertexAttribSlice(3, true, s{}, 1)
//
// to bind the 1st element in struct s to attrib 3
//
// Precondition: VBO bound to ARRAY_BUFFER target containing data of array type dummy
func VertexAttribSlice(index uint, normalized bool, dummy interface{}, dummy_index int) error {
data, err := sliceAttrib(dummy, dummy_index)
if err != nil {
return err
}
C.glVertexAttribPointer(C.GLuint(index), C.GLint(data.Elements), C.GLenum(data.Gltype), glBool(normalized), C.GLsizei(data.Stride), unsafe.Pointer(data.Offset))
return nil
}
func VertexAttribPointer(dst Attrib, size int, ty Enum, normalized bool, stride, offset int) {
defer func() {
errstr := errDrain()
log.Printf("gl.VertexAttribPointer(%v, %v, %v, %v, %v, %v) %v", dst, size, ty, normalized, stride, offset, errstr)
}()
n := glBoolean(normalized)
s := C.GLsizei(stride)
C.glVertexAttribPointer(dst.c(), C.GLint(size), ty.c(), n, s, unsafe.Pointer(uintptr(offset)))
}
func VertexAttribPointer(
indx uint32, size int32, type_ Enum,
normalized bool, stride Sizei, ptr Void) {
C.glVertexAttribPointer(
C.GLuint(indx),
C.GLint(size),
C.GLenum(type_),
glBoolean(normalized),
C.GLsizei(stride),
unsafe.Pointer(ptr))
}
// EnableAttrib calls glEnableVertexAttribArray and glVertexAttribPointer to activate an attribute and connect it to a buffer object.
// offset specifies the first vertex, stride specifies the distance from the beginning of one vertex to the next, size specifies the number of components in a vertex (all these arguments are in units of array elements, not bytes like the underlying API).
// The byte offset of component j of vertex i is thus calculated as: sizeof(data[0]) * (offset + stride * i + j), where data is the parameter passed to Buffer.Set
func (p *Program) EnableAttrib(loc string, buf *Buffer, offset int, size int, stride int, norm bool) {
n := FALSE
if norm {
n = TRUE
}
buf.Bind(ARRAY_BUFFER)
attr := p.attr[loc]
C.glEnableVertexAttribArray(attr)
C.glVertexAttribPointer(attr, C.GLint(size), buf.t, C.GLboolean(n), C.GLsizei(stride*buf.ts), unsafe.Pointer(uintptr(buf.ts*offset)))
buf.Unbind(ARRAY_BUFFER)
}
func VertexAttribPointer(
indx uint32, size int32, type_ Enum,
normalized bool, stride Sizei, ptr interface{}) {
C.glVertexAttribPointer(
C.GLuint(indx),
C.GLint(size),
C.GLenum(type_),
glBoolean(normalized),
C.GLsizei(stride),
unsafe.Pointer(reflect.ValueOf(ptr).Pointer()))
}
func (game *game) initGL() {
log.Printf("GL_VERSION: %v GL_RENDERER: %v GL_VENDOR %v\n",
GetString(C.GL_VERSION), GetString(C.GL_RENDERER), GetString(C.GL_VENDOR))
log.Printf("GL_EXTENSIONS: %v\n", GetString(C.GL_EXTENSIONS))
C.glClearColor(0.0, 0.0, 0.0, 1.0)
C.glEnable(C.GL_CULL_FACE)
C.glEnable(C.GL_DEPTH_TEST)
game.prog = createProgram(vertShaderSrcDef, fragShaderSrcDef)
posAttrib := attribLocation(game.prog, "vPosition")
game.offsetUni = uniformLocation(game.prog, "offset")
game.colorUni = uniformLocation(game.prog, "color")
C.glUseProgram(game.prog)
C.glEnableVertexAttribArray(C.GLuint(posAttrib))
vertVBO := GenBuffer()
checkGLError()
C.glBindBuffer(C.GL_ARRAY_BUFFER, vertVBO)
verts := []float32{.0, 0.5, -0.5, -0.5, 0.5, -0.5}
C.glBufferData(C.GL_ARRAY_BUFFER, C.GLsizeiptr(len(verts)*int(unsafe.Sizeof(verts[0]))), unsafe.Pointer(&verts[0]), C.GL_STATIC_DRAW)
C.glVertexAttribPointer(C.GLuint(posAttrib), 2, C.GL_FLOAT, C.GL_FALSE, 0, unsafe.Pointer(uintptr(0)))
}
func VertexAttribPointer(dst Attrib, size int, ty Enum, normalized bool, stride int, offset unsafe.Pointer) {
n := glBoolean(normalized)
s := C.GLsizei(stride)
C.glVertexAttribPointer(dst.c(), C.GLint(size), ty.c(), n, s, offset)
}
func (indx AttribLocation) AttribPointer(size uint, typ GLenum, normalized bool, stride int, pointer interface{}) {
C.glVertexAttribPointer(C.GLuint(indx), C.GLint(size), C.GLenum(typ),
glBool(normalized), C.GLsizei(stride), ptr(pointer))
}
func VertexAttribPointer(indx uint, size int, type_ uint, normalized bool, stride int, ptr uintptr) {
C.glVertexAttribPointer(C.GLuint(indx), C.GLint(size), C.GLenum(type_),
glBoolean(normalized), C.GLsizei(stride), unsafe.Pointer(ptr))
}
func (attrib vattrib) Pointer(size int, stride int, offset uintptr) {
C.glVertexAttribPointer(attrib.index, C.GLint(size), C.GL_FLOAT, C.GL_FALSE, C.GLsizei(stride), unsafe.Pointer(offset))
}
func (attrib FloatAttrib) Pointerf(size int, stride int, data []float32) {
C.glVertexAttribPointer(attrib.index, C.GLint(size), C.GL_FLOAT, C.GL_FALSE, C.GLsizei(stride), unsafe.Pointer(&data[0]))
}