/// <summary>
/// 用随机颜色更新当前的颜色。
/// </summary>
public void UpdateColorBuffer()
{
var colorArray = new UnmanagedArray<vec3>(size * size * size * 8);
Random random = new Random();
int index = 0;
for (int i = 0; i < size; i++)
{
for (int j = 0; j < size; j++)
{
for (int k = 0; k < size; k++)
{
//vec3 color = new vec3((float)random.NextDouble(), (float)random.NextDouble(), (float)random.NextDouble());
for (int cubeIndex = 0; cubeIndex < 8; cubeIndex++)
{
vec3 color = new vec3((float)random.NextDouble(), (float)random.NextDouble(), (float)random.NextDouble());
colorArray[index++] = color;
}
}
}
}
// update buffer object.
GL.BindBuffer(BufferTarget.ArrayBuffer, this.colorBuffer[0]);
IntPtr destColors = GL.MapBuffer(BufferTarget.ArrayBuffer, MapBufferAccess.ReadWrite);
colorArray.CopyTo(destColors);
GL.UnmapBuffer(BufferTarget.ArrayBuffer);
// This do the same thing: update buffer object
using (var mappingBuffer = new MappingBuffer(BufferTarget.ArrayBuffer, this.colorBuffer[0], MapBufferAccess.ReadWrite))
{
colorArray.CopyTo(mappingBuffer.BufferPointer);
}
colorArray.Dispose();
}
private void DoRender(object sender, PaintEventArgs e)
{
// Compute the MVP (Model View Projection matrix)
{
GL.BindBuffer(BufferTarget.UniformBuffer, BufferName[1]);//BufferName[TRANSFORM]
var Pointer = GL.MapBufferRange(GL.GL_UNIFORM_BUFFER, 0, 64, (uint)(GL.GL_MAP_WRITE_BIT | GL.GL_MAP_INVALIDATE_BUFFER_BIT));
var tmp = new UnmanagedArray<mat4>(1);
mat4 projection = this.camera.GetProjectionMat4();
mat4 view = this.camera.GetViewMat4();
tmp[0] = projection * view;
tmp.CopyTo(Pointer);
GL.UnmapBuffer(GL.GL_UNIFORM_BUFFER);
tmp.Dispose();
}
// Clear color buffer
//GL.ClearBufferfv(GL_COLOR, 0, &GL.m.vec4(0.0f, 0.0f, 0.0f, 1.0f)[0]);
GL.ClearBuffer(GL.GL_COLOR, 0, new float[] { 0.0f, 0.0f, 0.0f, 1.0f });
// First draw, capture the attributes
// Disable rasterisation, vertices processing only!
GL.Enable(GL.GL_RASTERIZER_DISCARD);
transformProgram.Bind();
GL.BindVertexArray(transformArray[0]);
//GL.BindBufferBase(GL.GL_UNIFORM_BUFFER, semantic.uniform.TRANSFORM0, BufferName[buffer.TRANSFORM]);
GL.BindBufferBase(GL.GL_UNIFORM_BUFFER, 1, BufferName[1]);
GL.BindTransformFeedback(GL.GL_TRANSFORM_FEEDBACK, feedbackObj[0]);
GL.BeginTransformFeedback(GL.GL_TRIANGLES);
GL.DrawArraysInstanced(GL.GL_TRIANGLES, 0, 6, 1);//VertexCount: 6
GL.EndTransformFeedback();
GL.BindTransformFeedback(GL.GL_TRANSFORM_FEEDBACK, 0);
GL.Disable(GL.GL_RASTERIZER_DISCARD);
// Second draw, reuse the captured attributes
feedbackProgram.Bind();
GL.BindVertexArray(feedbackArray[0]);
GL.DrawTransformFeedback(GL.GL_TRIANGLES, feedbackObj[0]);
}
