func onPaint(sz size.Event) {
gl.ClearColor(rgb(156), rgb(39), rgb(176), 1)
gl.Clear(gl.COLOR_BUFFER_BIT)
var rotationMatrix = []float32{
f32.Cos(-alpha), -f32.Sin(-alpha), 0.0,
f32.Sin(-alpha), f32.Cos(-alpha), 0.0,
0.0, 0.0, 1.0,
}
gl.UseProgram(program)
// setting color
gl.Uniform4f(color, rgb(255), rgb(255), rgb(255), 1)
gl.UniformMatrix3fv(matrixId, rotationMatrix)
gl.Uniform1f(resolutionId, resIndex)
gl.BindBuffer(gl.ARRAY_BUFFER, swasBuffer)
gl.EnableVertexAttribArray(position)
gl.VertexAttribPointer(position, 3, gl.FLOAT, false, 0, 0)
gl.DrawArrays(gl.LINES, 0, 16)
gl.DisableVertexAttribArray(position)
gl.UseProgram(texProgram)
// setting color
gl.Uniform4f(color2, rgb(130), rgb(50), rgb(80), 1)
gl.Uniform1f(resolutionId2, resIndex)
gl.UniformMatrix3fv(matrixId2, rotationMatrix)
gl.BindBuffer(gl.ARRAY_BUFFER, quadBuffer)
gl.EnableVertexAttribArray(position2)
gl.VertexAttribPointer(position2, 3, gl.FLOAT, false, 0, 0)
gl.BindBuffer(gl.ARRAY_BUFFER, quadTexBuffer)
gl.EnableVertexAttribArray(textureCoords)
gl.VertexAttribPointer(textureCoords, 2, gl.FLOAT, false, 0, 0)
gl.Uniform1i(gl.GetUniformLocation(texProgram, "myTexture"), 0)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, textureId)
gl.DrawArrays(gl.TRIANGLES, 0, 6)
gl.DisableVertexAttribArray(position2)
gl.DisableVertexAttribArray(textureCoords)
if spin == true {
alpha += 0.1
}
if alpha >= 360 {
alpha = 0.0
}
}
// writeAffine writes the contents of an Affine to a 3x3 matrix GL uniform.
func writeAffine(u gl.Uniform, a *f32.Affine) {
var m [9]float32
m[0*3+0] = a[0][0]
m[0*3+1] = a[1][0]
m[0*3+2] = 0
m[1*3+0] = a[0][1]
m[1*3+1] = a[1][1]
m[1*3+2] = 0
m[2*3+0] = a[0][2]
m[2*3+1] = a[1][2]
m[2*3+2] = 1
gl.UniformMatrix3fv(u, m[:])
}
func writeAff3(u gl.Uniform, a f64.Aff3) {
var m [9]float32
m[0*3+0] = float32(a[0*3+0])
m[0*3+1] = float32(a[1*3+0])
m[0*3+2] = 0
m[1*3+0] = float32(a[0*3+1])
m[1*3+1] = float32(a[1*3+1])
m[1*3+2] = 0
m[2*3+0] = float32(a[0*3+2])
m[2*3+1] = float32(a[1*3+2])
m[2*3+2] = 1
gl.UniformMatrix3fv(u, m[:])
}