/// <summary>
/// Vertex' attribute buffer's pointer.
/// </summary>
/// <param name="varNameInVertexShader">此顶点属性VBO对应于vertex shader中的哪个in变量？<para>Mapping variable's name in vertex shader.</para></param>
/// <param name="bufferId">用glGenBuffers()得到的VBO的Id。<para>Id got from glGenBuffers();</para></param>
/// <param name="config">This <paramref name="config"/> decides parameters' values in glVertexAttribPointer(attributeLocation, size, type, false, 0, IntPtr.Zero);
/// </param>
/// <param name="length">此VBO含有多个个元素？<para>How many elements?</para></param>
/// <param name="byteLength">此VBO中的数据在内存中占用多少个字节？<para>How many bytes in this buffer?</para></param>
/// <param name="instancedDivisor">0: not instanced. 1: instanced divisor is 1.</param>
/// <param name="patchVertexes">How many vertexes makes a patch? No patch if <paramref name="patchVertexes"/> is 0.</param>
internal VertexAttributeBufferPtr(string varNameInVertexShader,
uint bufferId, VertexAttributeConfig config, int length, int byteLength,
uint instancedDivisor = 0, int patchVertexes = 0)
: base(bufferId, length, byteLength)
{
if (glVertexAttribPointer == null)
{
glVertexAttribPointer = OpenGL.GetDelegateFor <OpenGL.glVertexAttribPointer>();
glEnableVertexAttribArray = OpenGL.GetDelegateFor <OpenGL.glEnableVertexAttribArray>();
glVertexAttribDivisor = OpenGL.GetDelegateFor <OpenGL.glVertexAttribDivisor>();
glPatchParameteri = OpenGL.GetDelegateFor <OpenGL.glPatchParameteri>();
glPatchParameterfv = OpenGL.GetDelegateFor <OpenGL.glPatchParameterfv>();
}
this.VarNameInVertexShader = varNameInVertexShader;
this.Config = config;
this.InstancedDivisor = instancedDivisor;
this.PatchVertexes = patchVertexes;
}
/// <summary>
/// 在使用<see cref="VertexArrayObject"/>后，此方法只会执行一次。
/// This method will only be invoked once when using <see cref="VertexArrayObject"/>.
/// </summary>
/// <param name="shaderProgram"></param>
public void Standby(ShaderProgram shaderProgram)
{
int location = shaderProgram.GetAttributeLocation(this.VarNameInVertexShader);
if (location < 0)
{
throw new ArgumentException();
}
uint loc = (uint)location;
VBOConfigDetail detail = this.Config.Parse();
int patchVertexes = this.PatchVertexes;
uint divisor = this.InstancedDivisor;
// 选中此VBO
// select this VBO.
if (glBindBuffer == null)
{
glBindBuffer = OpenGL.GetDelegateFor <OpenGL.glBindBuffer>();
}
glBindBuffer(OpenGL.GL_ARRAY_BUFFER, this.BufferId);
for (uint i = 0; i < detail.locationCount; i++)
{
// 指定格式
// set up data format.
switch (detail.pointerType)
{
case VertexAttribPointerType.Default:
if (glVertexAttribPointer == null)
{
glVertexAttribPointer = OpenGL.GetDelegateFor <OpenGL.glVertexAttribPointer>();
}
glVertexAttribPointer(loc + i, detail.dataSize, detail.dataType, false, detail.stride, new IntPtr(i * detail.startOffsetUnit));
break;
case VertexAttribPointerType.Integer:
if (glVertexAttribIPointer != null)
{
if (glVertexAttribIPointer == null)
{
glVertexAttribIPointer = OpenGL.GetDelegateFor <OpenGL.glVertexAttribIPointer>();
}
glVertexAttribIPointer(loc + i, detail.dataSize, detail.dataType, detail.stride, new IntPtr(i * detail.startOffsetUnit));
}
else
{
if (glVertexAttribPointer == null)
{
glVertexAttribPointer = OpenGL.GetDelegateFor <OpenGL.glVertexAttribPointer>();
}
glVertexAttribPointer(loc + i, detail.dataSize, detail.dataType, false, detail.stride, new IntPtr(i * detail.startOffsetUnit));
}
break;
case VertexAttribPointerType.Long:
if (glVertexAttribLPointer != null)
{
if (glVertexAttribLPointer == null)
{
glVertexAttribLPointer = OpenGL.GetDelegateFor <OpenGL.glVertexAttribLPointer>();
}
glVertexAttribLPointer(loc + i, detail.dataSize, detail.dataType, detail.stride, new IntPtr(i * detail.startOffsetUnit));
}
else
{
if (glVertexAttribPointer == null)
{
glVertexAttribPointer = OpenGL.GetDelegateFor <OpenGL.glVertexAttribPointer>();
}
glVertexAttribPointer(loc + i, detail.dataSize, detail.dataType, false, detail.stride, new IntPtr(i * detail.startOffsetUnit));
}
break;
default:
throw new NotImplementedException();
}
if (patchVertexes > 0)// tessellation shading.
{
if (glPatchParameteri != null)
{
if (glPatchParameteri == null)
{
glPatchParameteri = OpenGL.GetDelegateFor <OpenGL.glPatchParameteri>();
}
glPatchParameteri(OpenGL.GL_PATCH_VERTICES, patchVertexes);
}
}
// 启用
// enable this VBO.
if (glEnableVertexAttribArray == null)
{
glEnableVertexAttribArray = OpenGL.GetDelegateFor <OpenGL.glEnableVertexAttribArray>();
}
glEnableVertexAttribArray(loc + i);
if (divisor > 0)// instanced rendering.
{
if (glVertexAttribDivisor == null)
{
glVertexAttribDivisor = OpenGL.GetDelegateFor <OpenGL.glVertexAttribDivisor>();
}
glVertexAttribDivisor(loc + i, divisor);
}
}
glBindBuffer(OpenGL.GL_ARRAY_BUFFER, 0);
}
/// <summary>
/// 在使用<see cref="VertexArrayObject"/>后，此方法只会执行一次。
/// This method will only be invoked once when using <see cref="VertexArrayObject"/>.
/// </summary>
/// <param name="shaderProgram"></param>
public void Standby(ShaderProgram shaderProgram)
{
int location = shaderProgram.GetAttributeLocation(this.VarNameInVertexShader);
if (location < 0) { throw new ArgumentException(); }
uint loc = (uint)location;
VBOConfigDetail detail = this.Config.Parse();
int patchVertexes = this.PatchVertexes;
uint divisor = this.InstancedDivisor;
// 选中此VBO
// select this VBO.
if (glBindBuffer == null) { glBindBuffer = OpenGL.GetDelegateFor<OpenGL.glBindBuffer>(); }
glBindBuffer(OpenGL.GL_ARRAY_BUFFER, this.BufferId);
for (uint i = 0; i < detail.locationCount; i++)
{
// 指定格式
// set up data format.
switch (detail.pointerType)
{
case VertexAttribPointerType.Default:
if (glVertexAttribPointer == null) { glVertexAttribPointer = OpenGL.GetDelegateFor<OpenGL.glVertexAttribPointer>(); }
glVertexAttribPointer(loc + i, detail.dataSize, detail.dataType, false, detail.stride, new IntPtr(i * detail.startOffsetUnit));
break;
case VertexAttribPointerType.Integer:
if (glVertexAttribIPointer != null)
{
if (glVertexAttribIPointer == null) { glVertexAttribIPointer = OpenGL.GetDelegateFor<OpenGL.glVertexAttribIPointer>(); }
glVertexAttribIPointer(loc + i, detail.dataSize, detail.dataType, detail.stride, new IntPtr(i * detail.startOffsetUnit));
}
else
{
if (glVertexAttribPointer == null) { glVertexAttribPointer = OpenGL.GetDelegateFor<OpenGL.glVertexAttribPointer>(); }
glVertexAttribPointer(loc + i, detail.dataSize, detail.dataType, false, detail.stride, new IntPtr(i * detail.startOffsetUnit));
}
break;
case VertexAttribPointerType.Long:
if (glVertexAttribLPointer != null)
{
if (glVertexAttribLPointer == null) { glVertexAttribLPointer = OpenGL.GetDelegateFor<OpenGL.glVertexAttribLPointer>(); }
glVertexAttribLPointer(loc + i, detail.dataSize, detail.dataType, detail.stride, new IntPtr(i * detail.startOffsetUnit));
}
else
{
if (glVertexAttribPointer == null) { glVertexAttribPointer = OpenGL.GetDelegateFor<OpenGL.glVertexAttribPointer>(); }
glVertexAttribPointer(loc + i, detail.dataSize, detail.dataType, false, detail.stride, new IntPtr(i * detail.startOffsetUnit));
}
break;
default:
throw new NotImplementedException();
}
if (patchVertexes > 0)// tessellation shading.
{
if (glPatchParameteri != null)
{
if (glPatchParameteri == null) { glPatchParameteri = OpenGL.GetDelegateFor<OpenGL.glPatchParameteri>(); }
glPatchParameteri(OpenGL.GL_PATCH_VERTICES, patchVertexes);
}
}
// 启用
// enable this VBO.
if (glEnableVertexAttribArray == null) { glEnableVertexAttribArray = OpenGL.GetDelegateFor<OpenGL.glEnableVertexAttribArray>(); }
glEnableVertexAttribArray(loc + i);
if (divisor > 0)// instanced rendering.
{
if (glVertexAttribDivisor == null) { glVertexAttribDivisor = OpenGL.GetDelegateFor<OpenGL.glVertexAttribDivisor>(); }
glVertexAttribDivisor(loc + i, divisor);
}
}
glBindBuffer(OpenGL.GL_ARRAY_BUFFER, 0);
}
