//! On load window (once)
protected override void OnLoad()
{
_version = openGLFactory.NewVersionInformation(Console.WriteLine);
_extensions = openGLFactory.NewExtensionInformation();
_debug_callback = openGLFactory.NewDebugCallback(Console.WriteLine);
// Version strings
_version.Retrieve();
// Get OpenGL extensions
_extensions.Retrieve();
// Debug callback
_debug_callback.Init();
// create Vertex Array Object, Array Buffer Object and Element Array Buffer Object
// ...
// Create shader program
string compute_shader =
@"#version 460
layout(local_size_x = 1, local_size_y = 1) in;
layout(rgba32f, binding = 1) writeonly uniform image2D img_output;
layout(location = 1) uniform vec4 u_color;
layout(location = 2) uniform float u_margin;
layout(location = 3) uniform float u_random;
layout(std430, binding = 1) buffer TCoord1
{
vec4 pos;
} coord_inout;
vec4[7] constants = vec4[7](
vec4(0.0, 0.85, 0.2, -0.15),
vec4(0.0, 0.04, -0.26, 0.28),
vec4(0.0, -0.04, 0.23, 0.26),
vec4(0.16, 0.85, 0.22, 0.24),
vec4(0.0, 0.0, 0.0, 0.0 ),
vec4(0.0, 1.6, 1.6, 0.44),
vec4(1.0, 86.0, 93.0, 100.0 ));
void main() {
vec2 dims = vec2(imageSize(img_output)); // fetch image dimensions
int i = 0;
for (; i < 4; ++i)
{
if (u_random*100.0 < constants[6][i])
break;
}
i = min(i, 3);
vec2 fern = vec2(
constants[0][i] * coord_inout.pos.x + constants[1][i] * coord_inout.pos.y + constants[4][i],
constants[2][i] * coord_inout.pos.x + constants[3][i] * coord_inout.pos.y + constants[5][i]);
coord_inout.pos.xy = fern;
vec2 pixel_coords = vec2(
(fern.x + 2.1820 + u_margin) * dims.x / (2.1820 + 2.6558 + 2.0 * u_margin),
dims.y - (-fern.y + 9.9983 + u_margin) * dims.y / (9.9983 + 2.0 * u_margin));
// output to a specific pixel in the image
imageStore(img_output, ivec2(pixel_coords), u_color);
}";
this._compute_prog = openGLFactory.ComputeShaderProgram(compute_shader);
this._compute_prog.Generate();
// Model view projection shader storage block objects and buffers
_coord_ssbo = openGLFactory.NewStorageBuffer();
TCoordinate coord_data = new TCoordinate(Vector2.Zero);
this._coord_ssbo.Create(ref coord_data, IStorageBuffer.Usage.ReadWrite);
this._coord_ssbo.Bind(1);
// framebuffers
_fbo = openGLFactory.NewFramebuffer();
_fbo.Create(_image_cx, _image_cy, IFramebuffer.Kind.texture, IFramebuffer.Format.RGBA_F32, true, false);
_fbo.Clear(new Color4(0.2f, 0.1f, 0.0f, 1.0f));
// states
GL.ClearColor(0.0f, 0.0f, 0.0f, 0.0f);
base.OnLoad();
}