/// <summary>
/// Helper method to draw immediate preview of tileset tile.
/// </summary>
/// <remarks>
/// <para>Attached prefab will also be included in preview when applicable.</para>
/// </remarks>
/// <param name="context">Describes context of tile that is being previewed.</param>
/// <param name="previewMaterial">Material to use for preview.</param>
/// <param name="previewTile">Data for preview tile.</param>
/// <param name="transformer">Brush used to transform painted tile.
/// The <see cref="Brush.scaleMode"/> and <see cref="Brush.applyPrefabTransform"/>
/// fields of transform brush should be used. <c>transformer</c> may refer to this
/// brush, or it may refer to another (like alias or oriented for example).</param>
protected void DrawImmediateTilePreview(IBrushContext context, Material previewMaterial, TileData previewTile, Brush transformer)
{
var atlasTexture = Tileset.AtlasTexture;
if (atlasTexture == null)
{
return;
}
// Prepare mesh for tile background.
Rect texCoords = Tileset.CalculateTexCoords(previewTile.tilesetIndex);
var mesh = ImmediatePreviewUtility.UpdateQuadPreviewMesh(texCoords);
// Compute matrix for tile background.
var tileSystem = context.TileSystem;
Matrix4x4 matrix;
tileSystem.CalculateTileMatrix(out matrix, context.Row, context.Column, TileFacing.Sideways, previewTile.Rotation);
MathUtility.MultiplyMatrixByScale(ref matrix, tileSystem.CalculateCellSizeScale(previewTile.Rotation));
matrix = ImmediatePreviewUtility.Matrix * matrix;
// Draw tile background.
previewMaterial.mainTexture = atlasTexture;
ImmediatePreviewUtility.DrawNow(previewMaterial, mesh, matrix);
// Draw preview of tile attachment?
if (this.attachPrefab != null)
{
int rotation = this.applySimpleRotationToAttachment ? previewTile.PaintedRotation : 0;
var attachmentTransform = this.attachPrefab.transform;
matrix = tileSystem.transform.localToWorldMatrix * transformer.GetTransformMatrix(tileSystem, context.Row, context.Column, rotation, attachmentTransform);
ImmediatePreviewUtility.DrawNow(previewMaterial, attachmentTransform, matrix, context.Brush as IMaterialMappings);
}
}