Fix transforms not rendering (#1771)

Co-authored-by: amylizzle <[email protected]>

OpenDreamClient/Rendering/DreamViewOverlay.cs

@@ -415,12 +415,15 @@ public void DrawIcon(DrawingHandleWorld handle, Vector2i renderTargetSize, Rende
         //KEEP_TOGETHER groups
         if (iconMetaData.KeepTogetherGroup?.Count > 0) {
             // TODO: Use something better than a hardcoded 64x64 fallback
-            iconMetaData.TextureOverride = ProcessKeepTogether(handle, iconMetaData, iconMetaData.Texture?.Size ?? (64,64));
+            Vector2i ktSize = iconMetaData.Texture?.Size ?? (64,64);
+            iconMetaData.TextureOverride = ProcessKeepTogether(handle, iconMetaData, ktSize);
+            positionOffset -= ((ktSize/EyeManager.PixelsPerMeter) - Vector2.One) * new Vector2(0.5f); //correct for KT group texture offset
         }
 
         var pixelPosition = (iconMetaData.Position + positionOffset) * EyeManager.PixelsPerMeter;
         var frame = iconMetaData.Texture;
 
+
         //if frame is null, this doesn't require a draw, so return NOP
         if (frame == null)
             return;
@@ -437,10 +440,10 @@ public void DrawIcon(DrawingHandleWorld handle, Vector2i renderTargetSize, Rende
 
         if (goFastOverride || icon.Appearance == null || icon.Appearance.Filters.Count == 0) {
             //faster path for rendering unfiltered sprites
-            DrawIconFast(handle, renderTargetSize, frame, pixelPosition, GetBlendAndColorShader(iconMetaData));
+            DrawIconFast(handle, renderTargetSize, frame, pixelPosition, iconMetaData.TransformToApply, GetBlendAndColorShader(iconMetaData));
         } else {
             //Slower path for filtered icons
-            DrawIconSlow(handle, frame, iconMetaData, renderTargetSize, pixelPosition);
+            DrawIconSlow(handle, frame, iconMetaData, renderTargetSize, pixelPosition, iconMetaData.TransformToApply);
         }
     }
 
@@ -748,8 +751,9 @@ private Texture ProcessKeepTogether(DrawingHandleWorld handle, RendererMetaData
         iconMetaData.AlphaToApply = 1f;
         iconMetaData.BlendMode = BlendMode.Default;
 
-        List<RendererMetaData> ktItems = new List<RendererMetaData>(iconMetaData.KeepTogetherGroup!.Count+1);
-        ktItems.Add(iconMetaData);
+        List<RendererMetaData> ktItems = new List<RendererMetaData>(iconMetaData.KeepTogetherGroup!.Count + 1) {
+            iconMetaData
+        };
         ktItems.AddRange(iconMetaData.KeepTogetherGroup);
         iconMetaData.KeepTogetherGroup.Clear();
 
@@ -760,7 +764,7 @@ private Texture ProcessKeepTogether(DrawingHandleWorld handle, RendererMetaData
 
         handle.RenderInRenderTarget(tempTexture, () => {
             foreach (RendererMetaData ktItem in ktItems) {
-                DrawIcon(handle, tempTexture.Size, ktItem, -ktItem.Position);
+                DrawIcon(handle, tempTexture.Size, ktItem, -ktItem.Position+((tempTexture.Size/EyeManager.PixelsPerMeter) - Vector2.One) * new Vector2(0.5f)); //draw the icon in the centre of the KT render target
             }
         }, null);
 
@@ -787,17 +791,33 @@ private Texture ProcessKeepTogether(DrawingHandleWorld handle, RendererMetaData
     /// Render a texture without applying any filters, making this faster and cheaper.
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static void DrawIconFast(DrawingHandleWorld handle, Vector2i renderTargetSize, Texture texture, Vector2 pos, ShaderInstance? shader) {
+    private static void DrawIconFast(DrawingHandleWorld handle, Vector2i renderTargetSize, Texture texture, Vector2 pos, Matrix3 transform, ShaderInstance? shader) {
         handle.UseShader(shader);
-        handle.SetTransform(CreateRenderTargetFlipMatrix(renderTargetSize, pos));
+
+        //extract scale component of transform
+        Vector2 scaleFactors = new Vector2(
+            MathF.Sqrt(MathF.Pow(transform.R0C0,2) + MathF.Pow(transform.R0C1,2)),
+            MathF.Sqrt(MathF.Pow(transform.R1C0,2) + MathF.Pow(transform.R1C1,2))
+        );
+        transform.R0C0 /= scaleFactors.X;
+        transform.R0C1 /= scaleFactors.X;
+        transform.R1C0 /= scaleFactors.Y;
+        transform.R1C1 /= scaleFactors.Y;
+
+        handle.SetTransform(
+            Matrix3.CreateTranslation(-texture.Size/2)  //translate to origin
+            * transform                                 //rotate and translate
+            * Matrix3.CreateTranslation(texture.Size/2) //translate back to original position
+            * Matrix3.CreateScale(scaleFactors)         //scale
+            * CreateRenderTargetFlipMatrix(renderTargetSize, pos-((scaleFactors-Vector2.One)*texture.Size/2))); //flip and apply scale-corrected translation
         handle.DrawTextureRect(texture, Box2.FromDimensions(Vector2.Zero, texture.Size));
     }
 
     /// <summary>
     /// A slower method of drawing an icon. This one renders an atom's filters.
     /// Use <see cref="DrawIconFast"/> instead if the icon has no special rendering needs.
     /// </summary>
-    private void DrawIconSlow(DrawingHandleWorld handle, Texture frame, RendererMetaData iconMetaData, Vector2i renderTargetSize, Vector2 pos) {
+    private void DrawIconSlow(DrawingHandleWorld handle, Texture frame, RendererMetaData iconMetaData, Vector2i renderTargetSize, Vector2 pos, Matrix3 transform) {
         //first we do ping pong rendering for the multiple filters
         // TODO: This should determine the size from the filters and their settings, not just double the original
         IRenderTexture ping = RentRenderTarget(frame.Size * 2);
@@ -827,17 +847,15 @@ private void DrawIconSlow(DrawingHandleWorld handle, Texture frame, RendererMeta
                 handle.UseShader(s);
 
                 // Technically this should be ping.Size, but they are the same size so avoid the extra closure alloc
-                var transform = CreateRenderTargetFlipMatrix(pong.Size, Vector2.Zero);
-
-                handle.SetTransform(transform);
+                handle.SetTransform(CreateRenderTargetFlipMatrix(pong.Size, Vector2.Zero));
                 handle.DrawTextureRect(pong.Texture, new Box2(Vector2.Zero, pong.Size));
             }, Color.Black.WithAlpha(0));
 
             (ping, pong) = (pong, ping);
         }
 
         //then we draw the actual icon with filters applied
-        DrawIconFast(handle, renderTargetSize, pong.Texture, pos - frame.Size / 2,
+        DrawIconFast(handle, renderTargetSize, pong.Texture, pos - frame.Size / 2, transform,
             //note we apply the color *before* the filters, so we ignore color here
             GetBlendAndColorShader(iconMetaData, ignoreColor: true)
         );