private void OnLoad(object sender, EventArgs e)
{
// initialize and bind framebuffer
_framebuffer = new Framebuffer();
_framebuffer.Bind(FramebufferTarget.Framebuffer);
// initialize a renderbuffer and bind it to the depth attachment
// to support depth testing while rendering to the texture
_depthBuffer = new Renderbuffer();
_depthBuffer.Init(RenderbufferStorage.DepthComponent, FramebufferWidth, FramebufferHeight);
_framebuffer.Attach(FramebufferTarget.Framebuffer, FramebufferAttachment.DepthAttachment, _depthBuffer);
// initialize texture and bind it to the color attachment
_texture = new Texture2D(SizedInternalFormat.Rgba8, FramebufferWidth, FramebufferHeight, 1);
_framebuffer.Attach(FramebufferTarget.Framebuffer, FramebufferAttachment.ColorAttachment0, _texture);
Framebuffer.Unbind(FramebufferTarget.Framebuffer);
// initialize demonstration geometry
_cube = new ColorCube();
_cube.UpdateBuffers();
_quad = new TexturedQuad();
_quad.UpdateBuffers();
// initialize shaders
_colorProgram = ProgramFactory.Create<SimpleColorProgram>();
_textureProgram = ProgramFactory.Create<SimpleTextureProgram>();
// set up vertex attributes for the cube
_cubeVao = new VertexArray();
_cubeVao.Bind();
_cubeVao.BindAttribute(_colorProgram.InPosition, _cube.VertexBuffer);
_cubeVao.BindAttribute(_colorProgram.InColor, _cube.ColorBuffer);
_cubeVao.BindElementBuffer(_cube.IndexBuffer);
// set up vertex attributes for the quad
_quadVao = new VertexArray();
_quadVao.Bind();
_quadVao.BindAttribute(_textureProgram.InPosition, _quad.VertexBuffer);
_quadVao.BindAttribute(_textureProgram.InTexCoord, _quad.TexCoordBuffer);
// set camera position
Camera.DefaultState.Position = new Vector3(0,0,3);
Camera.ResetToDefault();
// enable depth testing
GL.Enable(EnableCap.DepthTest);
}
private void OnLoad(object sender, EventArgs e)
{
// load texture from file
using (var bitmap = new Bitmap("Data/Textures/checker.jpg"))
{
BitmapTexture.CreateCompatible(bitmap, out _texture);
_texture.LoadBitmap(bitmap);
}
_texture.GenerateMipMaps();
// initialize sampler
_sampler = new Sampler();
_sampler.SetWrapMode(TextureWrapMode.Repeat);
// create vertex data for a big plane
const int a = 10;
const int b = 10;
var vertices = new[]
{
new Vertex(-a, 0,-a, 0, 0),
new Vertex( a, 0,-a, b, 0),
new Vertex(-a, 0, a, 0, b),
new Vertex( a, 0, a, b, b)
};
// create buffer object and upload vertex data
_vbo = new Buffer<Vertex>();
_vbo.Init(BufferTarget.ArrayBuffer, vertices);
// initialize shader
_program = ProgramFactory.Create<SimpleTextureProgram>();
// activate shader program
_program.Use();
// bind sampler
_sampler.Bind(TextureUnit.Texture0);
// bind texture
_program.Texture.BindTexture(TextureUnit.Texture0, _texture);
// which is equivalent to
//_program.Texture.Set(TextureUnit.Texture0);
//_texture.Bind(TextureUnit.Texture0);
// set up vertex array and attributes
_vao = new VertexArray();
_vao.Bind();
// memory layout of our data is XYZUVXYZUV...
// the buffer abstraction knows the total size of one "pack" of vertex data
// and if a vertex attribute is bound without further arguments the first N elements are taken from each pack
// where N is provided via the VertexAttribAttribute on the program property:
_vao.BindAttribute(_program.InPosition, _vbo);
// if data should not be taken from the start of each pack, the offset must be given in bytes
// to reach the texture coordinates UV the XYZ coordinates must be skipped, that is 3 floats, i.e. an offset of 12 bytes is needed
_vao.BindAttribute(_program.InTexCoord, _vbo, 12);
// if needed all the available arguments can be specified manually, e.g.
//_vao.BindAttribute(_program.InTexCoord, _vbo, 2, VertexAttribPointerType.Float, Marshal.SizeOf(typeof(Vertex)), 12, false);
// set default camera
Camera.DefaultState.Position = new Vector3(0, 0.5f, 3);
Camera.ResetToDefault();
// set a nice clear color
GL.ClearColor(Color.MidnightBlue);
}
