/// <summary>
/// Deletes the vertex buffer and the vertex array.
/// </summary>
protected override void DisposeInternal()
{
//delete opengl buffers
GL.DeleteVertexArray(_vertexArrayHandle);
GL.DeleteBuffer(_vertexBufferHandle);
//free certain fields?.
_shader = null;
CurrentTexture = null;
}
/// <summary>
/// Constructs a QuadRenderer with the specified max quad count and shader
/// </summary>
/// <param name="maxQuadCount">The maximum amount of quads that may be submitted for rendering at once.</param>
/// <param name="shader">The shader the renderer will use.</param>
public QuadRenderer(int maxQuadCount, QuadShader shader)
{
//Check that the arguments are valid
_shader = shader ?? throw new ArgumentNullException(nameof(shader));
MaxQuadCount =
maxQuadCount < 1 || maxQuadCount == int.MaxValue
? throw new ArgumentOutOfRangeException(nameof(maxQuadCount))
: maxQuadCount;
//Generate OpenGL buffers
_vertexBufferHandle = GL.GenBuffer();
_vertexArrayHandle = GL.GenVertexArray();
//Create the array to store the vertices client side
_vertices = new float[MaxQuadCount * FLOATS_PER_QUAD];
int sf = sizeof(float);
//Configure the vertex array and set the size of the buffer
GL.BindVertexArray(_vertexArrayHandle);
GL.BindBuffer(BufferTarget.ArrayBuffer, _vertexBufferHandle);
GL.BufferData(BufferTarget.ArrayBuffer, sf * _vertices.Length, _vertices, BufferUsageHint.StreamDraw);
int stride = FLOATS_PER_QUAD * sf;
GL.VertexAttribPointer(_shader.PosLocation, 4, VertexAttribPointerType.Float, false, stride, 0);
GL.VertexAttribPointer(_shader.TexLocation, 4, VertexAttribPointerType.Float, false, stride, 4 * sf);
GL.VertexAttribPointer(_shader.ColorLocation, 4, VertexAttribPointerType.Float, false, stride, 8 * sf);
GL.VertexAttribPointer(_shader.OriginLocation, 2, VertexAttribPointerType.Float, false, stride, sf * 12);
GL.VertexAttribPointer(_shader.ScaleLocation, 2, VertexAttribPointerType.Float, false, stride, sf * 14);
GL.VertexAttribPointer(_shader.RotLocation, 1, VertexAttribPointerType.Float, false, stride, sf * 16);
GL.EnableVertexAttribArray(_shader.PosLocation);
GL.EnableVertexAttribArray(_shader.TexLocation);
GL.EnableVertexAttribArray(_shader.ColorLocation);
GL.EnableVertexAttribArray(_shader.OriginLocation);
GL.EnableVertexAttribArray(_shader.ScaleLocation);
GL.EnableVertexAttribArray(_shader.RotLocation);
//Give the transform the identity value initially
Transform = Matrix4.Identity;
}