public static extern void ImDrawData_DeIndexAllBuffers(DrawData* drawData);
/// <summary>
/// Helper to scale the ClipRect field of each ImDrawCmd.
/// Use if your final output buffer is at a different scale than ImGui expects,
/// or if there is a difference between your window resolution and framebuffer resolution.
/// </summary>
/// <param name="drawData">Pointer to the DrawData to scale.</param>
/// <param name="scale">The scale to apply.</param>
public static unsafe void ScaleClipRects(DrawData* drawData, Vector2 scale)
{
for (int i = 0; i < drawData->CmdListsCount; i++)
{
DrawList* cmd_list = drawData->CmdLists[i];
for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
{
DrawCmd* drawCmdList = (DrawCmd*)cmd_list->CmdBuffer.Data;
DrawCmd* cmd = &drawCmdList[cmd_i];
cmd->ClipRect = new Vector4(cmd->ClipRect.X * scale.X, cmd->ClipRect.Y * scale.Y, cmd->ClipRect.Z * scale.X, cmd->ClipRect.W * scale.Y);
}
}
}
private unsafe void RenderImDrawData(DrawData* draw_data)
{
// Rendering
int display_w, display_h;
display_w = _nativeWindow.Width;
display_h = _nativeWindow.Height;
Vector4 clear_color = new Vector4(114f / 255f, 144f / 255f, 154f / 255f, 1.0f);
GL.Viewport(0, 0, display_w, display_h);
GL.ClearColor(clear_color.X, clear_color.Y, clear_color.Z, clear_color.W);
GL.Clear(ClearBufferMask.ColorBufferBit);
// We are using the OpenGL fixed pipeline to make the example code simpler to read!
// Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers.
int last_texture;
GL.GetInteger(GetPName.TextureBinding2D, out last_texture);
GL.PushAttrib(AttribMask.EnableBit | AttribMask.ColorBufferBit | AttribMask.TransformBit);
GL.Enable(EnableCap.Blend);
GL.BlendFunc(BlendingFactorSrc.SrcAlpha, BlendingFactorDest.OneMinusSrcAlpha);
GL.Disable(EnableCap.CullFace);
GL.Disable(EnableCap.DepthTest);
GL.Enable(EnableCap.ScissorTest);
GL.EnableClientState(ArrayCap.VertexArray);
GL.EnableClientState(ArrayCap.TextureCoordArray);
GL.EnableClientState(ArrayCap.ColorArray);
GL.Enable(EnableCap.Texture2D);
GL.UseProgram(0);
// Handle cases of screen coordinates != from framebuffer coordinates (e.g. retina displays)
IO io = ImGui.GetIO();
ImGui.ScaleClipRects(draw_data, io.DisplayFramebufferScale);
// Setup orthographic projection matrix
GL.MatrixMode(MatrixMode.Projection);
GL.PushMatrix();
GL.LoadIdentity();
GL.Ortho(
0.0f,
io.DisplaySize.X / io.DisplayFramebufferScale.X,
io.DisplaySize.Y / io.DisplayFramebufferScale.Y,
0.0f,
-1.0f,
1.0f);
GL.MatrixMode(MatrixMode.Modelview);
GL.PushMatrix();
GL.LoadIdentity();
// Render command lists
for (int n = 0; n < draw_data->CmdListsCount; n++)
{
DrawList* cmd_list = draw_data->CmdLists[n];
byte* vtx_buffer = (byte*)cmd_list->VtxBuffer.Data;
ushort* idx_buffer = (ushort*)cmd_list->IdxBuffer.Data;
DrawVert vert0 = *((DrawVert*)vtx_buffer);
DrawVert vert1 = *(((DrawVert*)vtx_buffer) + 1);
DrawVert vert2 = *(((DrawVert*)vtx_buffer) + 2);
GL.VertexPointer(2, VertexPointerType.Float, sizeof(DrawVert), new IntPtr(vtx_buffer + DrawVert.PosOffset));
GL.TexCoordPointer(2, TexCoordPointerType.Float, sizeof(DrawVert), new IntPtr(vtx_buffer + DrawVert.UVOffset));
GL.ColorPointer(4, ColorPointerType.UnsignedByte, sizeof(DrawVert), new IntPtr(vtx_buffer + DrawVert.ColOffset));
for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
{
DrawCmd* pcmd = &(((DrawCmd*)cmd_list->CmdBuffer.Data)[cmd_i]);
if (pcmd->UserCallback != IntPtr.Zero)
{
throw new NotImplementedException();
}
else
{
GL.BindTexture(TextureTarget.Texture2D, pcmd->TextureId.ToInt32());
GL.Scissor(
(int)pcmd->ClipRect.X,
(int)(io.DisplaySize.Y - pcmd->ClipRect.W),
(int)(pcmd->ClipRect.Z - pcmd->ClipRect.X),
(int)(pcmd->ClipRect.W - pcmd->ClipRect.Y));
ushort[] indices = new ushort[pcmd->ElemCount];
for (int i = 0; i < indices.Length; i++) { indices[i] = idx_buffer[i]; }
GL.DrawElements(PrimitiveType.Triangles, (int)pcmd->ElemCount, DrawElementsType.UnsignedShort, new IntPtr(idx_buffer));
}
idx_buffer += pcmd->ElemCount;
}
}
// Restore modified state
GL.DisableClientState(ArrayCap.ColorArray);
GL.DisableClientState(ArrayCap.TextureCoordArray);
GL.DisableClientState(ArrayCap.VertexArray);
GL.BindTexture(TextureTarget.Texture2D, last_texture);
GL.MatrixMode(MatrixMode.Modelview);
GL.PopMatrix();
GL.MatrixMode(MatrixMode.Projection);
GL.PopMatrix();
GL.PopAttrib();
_graphicsContext.SwapBuffers();
}
