private static void RenderDrawData(ImDrawDataPtr drawData, RID parent)
{
// allocate and clear out our CanvasItem pool as needed
int neededNodes = 0;
for (int i = 0; i < drawData.CmdListsCount; i++)
{
neededNodes += drawData.CmdListsRange[i].CmdBuffer.Size;
}
while (_children.Count < neededNodes)
{
RID newChild = VisualServer.CanvasItemCreate();
VisualServer.CanvasItemSetParent(newChild, parent);
VisualServer.CanvasItemSetDrawIndex(newChild, _children.Count);
_children.Add(newChild);
_meshes.Add(new ArrayMesh());
}
// trim unused nodes to reduce draw calls
while (_children.Count > neededNodes)
{
int idx = _children.Count - 1;
VisualServer.FreeRid(_children[idx]);
_children.RemoveAt(idx);
_meshes.RemoveAt(idx);
}
// render
drawData.ScaleClipRects(ImGui.GetIO().DisplayFramebufferScale);
int nodeN = 0;
for (int n = 0; n < drawData.CmdListsCount; n++)
{
ImDrawListPtr cmdList = drawData.CmdListsRange[n];
int idxOffset = 0;
int nVert = cmdList.VtxBuffer.Size;
Godot.Vector2[] vertices = new Godot.Vector2[nVert];
Godot.Color[] colors = new Godot.Color[nVert];
Godot.Vector2[] uvs = new Godot.Vector2[nVert];
for (int i = 0; i < cmdList.VtxBuffer.Size; i++)
{
var v = cmdList.VtxBuffer[i];
vertices[i] = new Godot.Vector2(v.pos.X, v.pos.Y);
// need to reverse the color bytes
byte[] col = BitConverter.GetBytes(v.col);
colors[i] = Godot.Color.Color8(col[0], col[1], col[2], col[3]);
uvs[i] = new Godot.Vector2(v.uv.X, v.uv.Y);
}
for (int cmdi = 0; cmdi < cmdList.CmdBuffer.Size; cmdi++, nodeN++)
{
ImDrawCmdPtr drawCmd = cmdList.CmdBuffer[cmdi];
int[] indices = new int[drawCmd.ElemCount];
for (int i = idxOffset, j = 0; i < idxOffset + drawCmd.ElemCount; i++, j++)
{
indices[j] = cmdList.IdxBuffer[i];
}
var arrays = new Godot.Collections.Array();
arrays.Resize((int)ArrayMesh.ArrayType.Max);
arrays[(int)ArrayMesh.ArrayType.Vertex] = vertices;
arrays[(int)ArrayMesh.ArrayType.Color] = colors;
arrays[(int)ArrayMesh.ArrayType.TexUv] = uvs;
arrays[(int)ArrayMesh.ArrayType.Index] = indices;
var mesh = _meshes[nodeN];
while (mesh.GetSurfaceCount() > 0)
{
mesh.SurfaceRemove(0);
}
mesh.AddSurfaceFromArrays(Mesh.PrimitiveType.Triangles, arrays);
RID child = _children[nodeN];
Texture tex = GetTexture(drawCmd.TextureId);
VisualServer.CanvasItemClear(child);
VisualServer.CanvasItemSetClip(child, true);
VisualServer.CanvasItemSetCustomRect(child, true, new Godot.Rect2(
drawCmd.ClipRect.X,
drawCmd.ClipRect.Y,
drawCmd.ClipRect.Z - drawCmd.ClipRect.X,
drawCmd.ClipRect.W - drawCmd.ClipRect.Y)
);
VisualServer.CanvasItemAddMesh(child, mesh.GetRid(), null, null, tex.GetRid(), new RID(null));
// why doesn't this quite work?
// VisualServer.CanvasItemAddTriangleArray(child, indices, vertices, colors, uvs, null, null, tex.GetRid(), -1, new RID(null));
idxOffset += (int)drawCmd.ElemCount;
}
}
}