/// <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>
/// <param name="varNameInVertexShader"></param>
public void Standby(ShaderProgram shaderProgram, string varNameInVertexShader)
{
int location = shaderProgram.GetAttributeLocation(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.
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:
glVertexAttribPointer(loc + i, detail.dataSize, detail.dataType, false, detail.stride, new IntPtr(i * detail.startOffsetUnit));
break;
case VertexAttribPointerType.Integer:
glVertexAttribIPointer(loc + i, detail.dataSize, detail.dataType, detail.stride, new IntPtr(i * detail.startOffsetUnit));
break;
case VertexAttribPointerType.Long:
glVertexAttribLPointer(loc + i, detail.dataSize, detail.dataType, detail.stride, new IntPtr(i * detail.startOffsetUnit));
break;
default:
throw new Exception("Unexpected VertexAttribPointerType type!");
}
if (patchVertexes > 0)// tessellation shading.
{
glPatchParameteri(OpenGL.GL_PATCH_VERTICES, patchVertexes);
}
// 启用
// enable this VBO.
glEnableVertexAttribArray(loc + i);
if (divisor > 0)// instanced rendering.
{
glVertexAttribDivisor(loc + i, divisor);
}
}
glBindBuffer(OpenGL.GL_ARRAY_BUFFER, 0);
}
/// <summary>
/// Gets parameter values for glVertexAttribPointer() and glEnable/DisableVertexAttribArray().
/// </summary>
/// <param name="config"></param>
internal static VBOConfigDetail Parse(this VBOConfig config)
{
var result = new VBOConfigDetail();
switch (config)
{
case VBOConfig.Byte:
result.dataSize = 1;
result.dataType = GL.GL_BYTE;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.BVec2:
result.dataSize = 2;
result.dataType = GL.GL_BYTE;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.BVec3:
result.dataSize = 3;
result.dataType = GL.GL_BYTE;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.BVec4:
result.dataSize = 4;
result.dataType = GL.GL_BYTE;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.Int:
result.dataSize = 1;
result.dataType = GL.GL_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.IVec2:
result.dataSize = 2;
result.dataType = GL.GL_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.IVec3:
result.dataSize = 3;
result.dataType = GL.GL_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.IVec4:
result.dataSize = 4;
result.dataType = GL.GL_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.UInt:
result.dataSize = 1;
result.dataType = GL.GL_UNSIGNED_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.UVec2:
result.dataSize = 2;
result.dataType = GL.GL_UNSIGNED_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.UVec3:
result.dataSize = 3;
result.dataType = GL.GL_UNSIGNED_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.UVec4:
result.dataSize = 4;
result.dataType = GL.GL_UNSIGNED_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.Float:
result.dataSize = 1;
result.dataType = GL.GL_FLOAT;
result.pointerType = VertexAttribPointerType.Default;
break;
case VBOConfig.Vec2:
result.dataSize = 2;
result.dataType = GL.GL_FLOAT;
result.pointerType = VertexAttribPointerType.Default;
break;
case VBOConfig.Vec3:
result.dataSize = 3;
result.dataType = GL.GL_FLOAT;
result.pointerType = VertexAttribPointerType.Default;
break;
case VBOConfig.Vec4:
result.dataSize = 4;
result.dataType = GL.GL_FLOAT;
result.pointerType = VertexAttribPointerType.Default;
break;
case VBOConfig.Double:
result.dataSize = 1;
result.dataType = GL.GL_DOUBLE;
result.pointerType = VertexAttribPointerType.Long;
break;
case VBOConfig.DVec2:
result.dataSize = 2;
result.dataType = GL.GL_DOUBLE;
result.pointerType = VertexAttribPointerType.Long;
break;
case VBOConfig.DVec3:
result.dataSize = 3;
result.dataType = GL.GL_DOUBLE;
result.pointerType = VertexAttribPointerType.Long;
break;
case VBOConfig.DVec4:
result.dataSize = 4;
result.dataType = GL.GL_DOUBLE;
result.pointerType = VertexAttribPointerType.Long;
break;
case VBOConfig.Mat2:
result.locationCount = 2;
result.dataSize = 2;
result.dataType = GL.GL_FLOAT;
result.stride = Marshal.SizeOf(typeof(mat2));
result.startOffsetUnit = Marshal.SizeOf(typeof(vec2));
result.pointerType = VertexAttribPointerType.Default;
break;
case VBOConfig.Mat3:
result.locationCount = 3;
result.dataSize = 3;
result.dataType = GL.GL_FLOAT;
result.stride = Marshal.SizeOf(typeof(mat3));
result.startOffsetUnit = Marshal.SizeOf(typeof(vec3));
result.pointerType = VertexAttribPointerType.Default;
break;
case VBOConfig.Mat4:
result.locationCount = 4;
result.dataSize = 4;
result.dataType = GL.GL_FLOAT;
result.stride = Marshal.SizeOf(typeof(mat4));
result.startOffsetUnit = Marshal.SizeOf(typeof(vec4));
result.pointerType = VertexAttribPointerType.Default;
break;
default:
throw new Exception("Unexpected VBOConfig!");
}
return(result);
}
/// <summary>
/// Gets parameter values for glVertexAttribPointer() and glEnable/DisableVertexAttribArray().
/// </summary>
/// <param name="config"></param>
internal static VBOConfigDetail Parse(this VBOConfig config)
{
var result = new VBOConfigDetail();
switch (config)
{
case VBOConfig.Byte:
result.dataSize = 1;
result.dataType = OpenGL.GL_BYTE;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.BVec2:
result.dataSize = 2;
result.dataType = OpenGL.GL_BYTE;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.BVec3:
result.dataSize = 3;
result.dataType = OpenGL.GL_BYTE;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.BVec4:
result.dataSize = 4;
result.dataType = OpenGL.GL_BYTE;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.Int:
result.dataSize = 1;
result.dataType = OpenGL.GL_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.IVec2:
result.dataSize = 2;
result.dataType = OpenGL.GL_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.IVec3:
result.dataSize = 3;
result.dataType = OpenGL.GL_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.IVec4:
result.dataSize = 4;
result.dataType = OpenGL.GL_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.UInt:
result.dataSize = 1;
result.dataType = OpenGL.GL_UNSIGNED_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.UVec2:
result.dataSize = 2;
result.dataType = OpenGL.GL_UNSIGNED_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.UVec3:
result.dataSize = 3;
result.dataType = OpenGL.GL_UNSIGNED_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.UVec4:
result.dataSize = 4;
result.dataType = OpenGL.GL_UNSIGNED_INT;
result.pointerType = VertexAttribPointerType.Integer;
break;
case VBOConfig.Float:
result.dataSize = 1;
result.dataType = OpenGL.GL_FLOAT;
result.pointerType = VertexAttribPointerType.Default;
break;
case VBOConfig.Vec2:
result.dataSize = 2;
result.dataType = OpenGL.GL_FLOAT;
result.pointerType = VertexAttribPointerType.Default;
break;
case VBOConfig.Vec3:
result.dataSize = 3;
result.dataType = OpenGL.GL_FLOAT;
result.pointerType = VertexAttribPointerType.Default;
break;
case VBOConfig.Vec4:
result.dataSize = 4;
result.dataType = OpenGL.GL_FLOAT;
result.pointerType = VertexAttribPointerType.Default;
break;
case VBOConfig.Double:
result.dataSize = 1;
result.dataType = OpenGL.GL_DOUBLE;
result.pointerType = VertexAttribPointerType.Long;
break;
case VBOConfig.DVec2:
result.dataSize = 2;
result.dataType = OpenGL.GL_DOUBLE;
result.pointerType = VertexAttribPointerType.Long;
break;
case VBOConfig.DVec3:
result.dataSize = 3;
result.dataType = OpenGL.GL_DOUBLE;
result.pointerType = VertexAttribPointerType.Long;
break;
case VBOConfig.DVec4:
result.dataSize = 4;
result.dataType = OpenGL.GL_DOUBLE;
result.pointerType = VertexAttribPointerType.Long;
break;
case VBOConfig.Mat2:
result.locationCount = 2;
result.dataSize = 2;
result.dataType = OpenGL.GL_FLOAT;
result.stride = Marshal.SizeOf(typeof(mat2));
result.startOffsetUnit = Marshal.SizeOf(typeof(vec2));
result.pointerType = VertexAttribPointerType.Default;
break;
case VBOConfig.Mat3:
result.locationCount = 3;
result.dataSize = 3;
result.dataType = OpenGL.GL_FLOAT;
result.stride = Marshal.SizeOf(typeof(mat3));
result.startOffsetUnit = Marshal.SizeOf(typeof(vec3));
result.pointerType = VertexAttribPointerType.Default;
break;
case VBOConfig.Mat4:
result.locationCount = 4;
result.dataSize = 4;
result.dataType = OpenGL.GL_FLOAT;
result.stride = Marshal.SizeOf(typeof(mat4));
result.startOffsetUnit = Marshal.SizeOf(typeof(vec4));
result.pointerType = VertexAttribPointerType.Default;
break;
default:
throw new NotImplementedException();
}
return result;
}
