func (m Mesh) draw() {
gl.EnableVertexAttribArray(0)
gl.EnableVertexAttribArray(1)
gl.EnableVertexAttribArray(2)
if m.vbo == 0 {
panic("attempt to set array buffer with VBO=0")
}
gl.BindBuffer(gl.ARRAY_BUFFER, m.vbo)
gl.VertexAttribPointer(0, 3, gl.FLOAT, false, VertexSize*4, gl.PtrOffset(0))
gl.VertexAttribPointer(1, 2, gl.FLOAT, false, VertexSize*4, gl.PtrOffset(12))
gl.VertexAttribPointer(2, 3, gl.FLOAT, false, VertexSize*4, gl.PtrOffset(20))
if m.vbo == 0 {
panic("attempt to set element array buffer with VBO=0")
}
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, m.ibo)
if m.size == 0 {
panic("attempt to draw elements with mesh size = 0")
}
gl.DrawElements(gl.TRIANGLES, m.size, gl.UNSIGNED_INT, gl.PtrOffset(0))
gl.DisableVertexAttribArray(0)
gl.DisableVertexAttribArray(1)
gl.DisableVertexAttribArray(2)
}
func (c *Context) DisableVertexAttribArray(p Program, location string) {
_ = c.runOnContextThread(func() error {
l := c.locationCache.GetAttribLocation(c, p, location)
gl.DisableVertexAttribArray(uint32(l))
return nil
})
}
func onDisplay(program uint32) {
coords := uint32(attributeCoord2d)
vcolor := uint32(attributeVColor)
gl.ClearColor(1.0, 1.0, 1.0, 1.0)
gl.Clear(gl.COLOR_BUFFER_BIT)
gl.UseProgram(program)
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
gl.Uniform1f(uniformFade, curFade)
gl.EnableVertexAttribArray(coords)
gl.EnableVertexAttribArray(vcolor)
gl.BindBuffer(gl.ARRAY_BUFFER, vboTriangle)
gl.VertexAttribPointer(coords, 2, gl.FLOAT, false, 5*floatSize, nil)
gl.VertexAttribPointer(vcolor, 3, gl.FLOAT, false, 5*floatSize, gl.PtrOffset(2*floatSize))
gl.DrawArrays(gl.TRIANGLES, 0, 3)
gl.DisableVertexAttribArray(vcolor)
gl.DisableVertexAttribArray(coords)
}
func onDisplay(program uint32, coords uint32) {
gl.ClearColor(1.0, 1.0, 1.0, 1.0)
gl.Clear(gl.COLOR_BUFFER_BIT)
gl.UseProgram(program)
gl.EnableVertexAttribArray(coords)
triangleVertices := []float32{
0.0, 0.8,
-0.8, -0.8,
0.8, -0.8}
gl.VertexAttribPointer(coords, 2, gl.FLOAT, false, 0, gl.Ptr(triangleVertices))
gl.DrawArrays(gl.TRIANGLES, 0, 3)
gl.DisableVertexAttribArray(coords)
}
func onDisplay(program uint32, coords uint32) {
gl.ClearColor(1.0, 1.0, 1.0, 1.0)
gl.Clear(gl.COLOR_BUFFER_BIT)
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
gl.UseProgram(program)
gl.EnableVertexAttribArray(coords)
gl.VertexAttribPointer(coords, 2, gl.FLOAT, false, 0, nil)
gl.DrawArrays(gl.TRIANGLES, 0, 3)
gl.DisableVertexAttribArray(coords)
}
// DisableVertexAttribArray disables a vertex attribute array.
//
// http://www.khronos.org/opengles/sdk/docs/man3/html/glDisableVertexAttribArray.xhtml
func DisableVertexAttribArray(a Attrib) {
gl.DisableVertexAttribArray(uint32(a.Value))
}
func (c *Context) DisableVertexAttribArray(p Program, location string) {
l := GetAttribLocation(c, p, location)
gl.DisableVertexAttribArray(uint32(l))
}
func (c *Context) DisableVertexAttribArray(index int) {
gl.DisableVertexAttribArray(uint32(index))
}