raylib: fix clip when targetting texture

When targetting a texture, raylib does not multiply the clipping rect by the window scale.
david-vanderson · Dec 5, 2024 · 88fa1e1 · 88fa1e1
1 parent 5abff13
commit 88fa1e1
Showing 1 changed file with 12 additions and 9 deletions.
diff --git a/src/backends/raylib_backend.zig b/src/backends/raylib_backend.zig
@@ -195,23 +195,26 @@ pub fn drawClippedTriangles(self: *RaylibBackend, texture: ?*anyopaque, vtx: []c
     c.rlDrawRenderBatchActive();
 
     if (clipr_in) |clip_rect| {
-        // clipr is in pixels, but raylib multiplies by GetWindowScaleDPI(), so we
-        // have to divide by that here
-        const clipr = dvuiRectToRaylib(clip_rect);
+        if (self.fb_width == null) {
+            // clipr is in pixels, but raylib multiplies by GetWindowScaleDPI(), so we
+            // have to divide by that here
+            const clipr = dvuiRectToRaylib(clip_rect);
 
-        // figure out how much we are losing by truncating x and y, need to add that back to w and h
-        const clipx: c_int = @intFromFloat(clipr.x);
-        const clipw: c_int = @intFromFloat(@ceil(clipr.width + clipr.x - @floor(clipr.x)));
+            // figure out how much we are losing by truncating x and y, need to add that back to w and h
+            const clipx: c_int = @intFromFloat(clipr.x);
+            const clipw: c_int = @intFromFloat(@ceil(clipr.width + clipr.x - @floor(clipr.x)));
 
-        if (self.fb_width == null) {
             const clipy: c_int = @intFromFloat(clipr.y);
             const cliph: c_int = @max(0, @as(c_int, @intFromFloat(@ceil(clipr.height + clipr.y - @floor(clipr.y)))));
             c.BeginScissorMode(clipx, clipy, clipw, cliph);
         } else {
+            // raylib does NOT multiply by the window scale when targeting a texture
+            const clipx: c_int = @intFromFloat(clip_rect.x);
+            const clipw: c_int = @intFromFloat(@ceil(clip_rect.w + clip_rect.x - @floor(clip_rect.x)));
             // need to swap y
-            const ry: f32 = @as(f32, @floatFromInt(self.fb_height.?)) / dvui.windowNaturalScale() - clipr.y - clipr.height;
+            const ry: f32 = @as(f32, @floatFromInt(self.fb_height.?)) - clip_rect.y - clip_rect.h;
             const y: c_int = @intFromFloat(ry);
-            const h: c_int = @intFromFloat(@ceil(clipr.height + ry - @floor(ry)));
+            const h: c_int = @intFromFloat(@ceil(clip_rect.h + ry - @floor(ry)));
             c.BeginScissorMode(clipx, y, clipw, h);
         }
     }