public unsafe SkyboxDrawer(IContext glContext)
{
this.glContext = glContext;
sampler = glContext.Create.Sampler();
sampler.SetMagFilter(TextureMagFilter.Linear);
sampler.SetMinFilter(TextureMinFilter.LinearMipmapLinear);
sampler.SetWrapR(TextureWrapMode.Clamp);
sampler.SetWrapS(TextureWrapMode.Clamp);
sampler.SetWrapT(TextureWrapMode.Clamp);
sampler.SetMaxAnisotropy(16f);
#region Shader Text
const string vertexShaderText =
@"#version 150
layout(std140) uniform Camera
{
mat4 ViewProjection;
};
in vec3 in_position;
out vec3 v_tex_coord;
void main()
{
vec4 worldPosition = vec4(in_position, 1.0f);
gl_Position = worldPosition * ViewProjection;
gl_Position.y = -gl_Position.y;
gl_Position.z = 2.0 * gl_Position.z - gl_Position.w;
v_tex_coord = vec3(-worldPosition.x, worldPosition.y, worldPosition.z);
}
";
const string fragmentShaderText =
@"#version 150
uniform samplerCube Texture;
in vec3 v_tex_coord;
out vec4 out_color;
void main()
{
out_color = texture(Texture, v_tex_coord);
}
";
#endregion
var vs = glContext.Create.VertexShader(vertexShaderText);
var fs = glContext.Create.FragmentShader(fragmentShaderText);
shaderProgram = glContext.Create.Program(new ShaderProgramDescription
{
VertexShaders = new[] { vs },
FragmentShaders = new[] { fs },
VertexAttributeNames = new[] { "in_position" },
UniformBufferNames = new[] { "Camera" },
SamplerNames = new[] { "Texture" }
});
var vertices = new[]
{
new Vector4(-10, -10, -1, 1),
new Vector4(-10, 10, -1, 1),
new Vector4(10, 10, -1, 1),
new Vector4(10, -10, -1, 1),
new Vector4(-10, -10, 1, 1),
new Vector4(-10, 10, 1, 1),
new Vector4(10, 10, 1, 1),
new Vector4(10, -10, 1, 1),
};
var indices = new[]
{
0, 1, 2, 0, 2, 3,
4, 5, 6, 4, 6, 7,
0, 4, 7, 0, 7, 3,
0, 4, 5, 0, 5, 1,
1, 5, 6, 1, 6, 2,
3, 7, 6, 3, 6, 2
};
IBuffer vertexBuffer;
fixed(Vector4 *data = vertices)
vertexBuffer = glContext.Create.Buffer(BufferTarget.Array, 4 * sizeof(float) * vertices.Length, BufferUsageHint.StaticDraw, (IntPtr)data);
IBuffer indexBuffer;
fixed(int *data = indices)
indexBuffer = glContext.Create.Buffer(BufferTarget.ElementArray, sizeof(int) * indices.Length, BufferUsageHint.StaticDraw, (IntPtr)data);
vao = glContext.Create.VertexArray();
vao.SetVertexAttributeF(0, vertexBuffer, VertexAttributeDimension.Three, VertexAttribPointerType.Float, false, 4 * sizeof(float), 0);
vao.SetElementArrayBuffer(indexBuffer);
cameraUb = new UniformBufferSugar <Matrix4x4>(glContext);
}