func (s *screenImpl) NewTexture(size image.Point) (screen.Texture, error) {
s.mu.Lock()
defer s.mu.Unlock()
if !gl.IsProgram(s.texture.program) {
p, err := compileProgram(textureVertexSrc, textureFragmentSrc)
if err != nil {
return nil, err
}
s.texture.program = p
s.texture.pos = gl.GetAttribLocation(p, "pos")
s.texture.mvp = gl.GetUniformLocation(p, "mvp")
s.texture.uvp = gl.GetUniformLocation(p, "uvp")
s.texture.inUV = gl.GetAttribLocation(p, "inUV")
s.texture.sample = gl.GetUniformLocation(p, "sample")
s.texture.quadXY = gl.CreateBuffer()
s.texture.quadUV = gl.CreateBuffer()
gl.BindBuffer(gl.ARRAY_BUFFER, s.texture.quadXY)
gl.BufferData(gl.ARRAY_BUFFER, quadXYCoords, gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, s.texture.quadUV)
gl.BufferData(gl.ARRAY_BUFFER, quadUVCoords, gl.STATIC_DRAW)
}
t := &textureImpl{
id: gl.CreateTexture(),
size: size,
}
gl.BindTexture(gl.TEXTURE_2D, t.id)
gl.TexImage2D(gl.TEXTURE_2D, 0, size.X, size.Y, gl.RGBA, gl.UNSIGNED_BYTE, nil)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
return t, nil
}
func (w *windowImpl) Fill(dr image.Rectangle, src color.Color, op draw.Op) {
if !gl.IsProgram(w.s.fill.program) {
p, err := compileProgram(fillVertexSrc, fillFragmentSrc)
if err != nil {
// TODO: initialize this somewhere else we can better handle the error.
panic(err.Error())
}
w.s.fill.program = p
w.s.fill.pos = gl.GetAttribLocation(p, "pos")
w.s.fill.mvp = gl.GetUniformLocation(p, "mvp")
w.s.fill.color = gl.GetUniformLocation(p, "color")
w.s.fill.quadXY = gl.CreateBuffer()
gl.BindBuffer(gl.ARRAY_BUFFER, w.s.fill.quadXY)
gl.BufferData(gl.ARRAY_BUFFER, quadXYCoords, gl.STATIC_DRAW)
}
gl.UseProgram(w.s.fill.program)
writeAff3(w.s.fill.mvp, w.vertexAff3(dr))
r, g, b, a := src.RGBA()
gl.Uniform4f(
w.s.fill.color,
float32(r)/65535,
float32(g)/65535,
float32(b)/65535,
float32(a)/65535,
)
gl.BindBuffer(gl.ARRAY_BUFFER, w.s.fill.quadXY)
gl.EnableVertexAttribArray(w.s.fill.pos)
gl.VertexAttribPointer(w.s.fill.pos, 2, gl.FLOAT, false, 0, 0)
gl.DrawArrays(gl.TRIANGLE_STRIP, 0, 4)
gl.DisableVertexAttribArray(w.s.fill.pos)
}
