func EnableVertexAttribArray(index Attrib) {
defer func() {
errstr := errDrain()
log.Printf("gl.EnableVertexAttribArray(%v) %v", index, errstr)
}()
C.glEnableVertexAttribArray(index.c())
}
// 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 (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 EnableVertexAttribArray(a Attrib) {
C.glEnableVertexAttribArray(a.c())
}
func EnableVertexAttribArray(
index uint32) {
C.glEnableVertexAttribArray(
C.GLuint(index))
}
func (indx AttribLocation) EnableArray() {
C.glEnableVertexAttribArray(C.GLuint(indx))
}
func (attrib vattrib) Enable() {
C.glEnableVertexAttribArray(attrib.index)
}
// EnableVertexAttribArray enables a vertex attribute array.
//
// http://www.khronos.org/opengles/sdk/docs/man3/html/glEnableVertexAttribArray.xhtml
func EnableVertexAttribArray(index Attrib) {
C.glEnableVertexAttribArray(index.c())
}
// Enable enables a generic vertex attribute array.
func (l VertexAttribArray) Enable() {
C.glEnableVertexAttribArray(C.GLuint(l))
}