From bdaedb601ce3f3bd87cc8fb773ae8ac912fd457b Mon Sep 17 00:00:00 2001 From: Paul Trojahn Date: Tue, 8 Oct 2019 20:52:30 +0200 Subject: [PATCH] Fix draw_rect OpenGL uses the diamond exit rule to rasterize lines. If we don't shift the points down and to the right by 0.5, the line can sometimes miss a pixel when it shouldn't. The final fragment of a line isn't drawn. By drawing the lines clockwise, we can avoid a missing pixel in the rectangle. See section 3.4.1 in the OpenGL 1.5 specification. Fixes #32279 --- drivers/gles2/rasterizer_canvas_gles2.cpp | 6 +++-- drivers/gles3/rasterizer_canvas_gles3.cpp | 6 +++-- scene/2d/canvas_item.cpp | 32 +++++++++++------------ 3 files changed, 24 insertions(+), 20 deletions(-) diff --git a/drivers/gles2/rasterizer_canvas_gles2.cpp b/drivers/gles2/rasterizer_canvas_gles2.cpp index 6be48a4c582..740f641e1e6 100644 --- a/drivers/gles2/rasterizer_canvas_gles2.cpp +++ b/drivers/gles2/rasterizer_canvas_gles2.cpp @@ -494,8 +494,10 @@ void RasterizerCanvasGLES2::_canvas_item_render_commands(Item *p_item, Item *cur if (line->width <= 1) { Vector2 verts[2] = { - Vector2(line->from.x, line->from.y), - Vector2(line->to.x, line->to.y) + // Offset the line slightly to make sure we always draw the pixel at the from coordinate. + // Without this, corners of rectangles might be missing a pixel. (See diamond exit rule and #32657) + Vector2(Math::floor(line->from.x) + 0.5, Math::floor(line->from.y) + 0.5), + Vector2(Math::floor(line->to.x) + 0.5, Math::floor(line->to.y) + 0.5) }; #ifdef GLES_OVER_GL diff --git a/drivers/gles3/rasterizer_canvas_gles3.cpp b/drivers/gles3/rasterizer_canvas_gles3.cpp index edffe852a29..e09ba755eab 100644 --- a/drivers/gles3/rasterizer_canvas_gles3.cpp +++ b/drivers/gles3/rasterizer_canvas_gles3.cpp @@ -548,8 +548,10 @@ void RasterizerCanvasGLES3::_canvas_item_render_commands(Item *p_item, Item *cur if (line->width <= 1) { Vector2 verts[2] = { - Vector2(line->from.x, line->from.y), - Vector2(line->to.x, line->to.y) + // Offset the line slightly to make sure we always draw the pixel at the from coordinate. + // Without this, corners of rectangles might be missing a pixel. (See diamond exit rule and #32657) + Vector2(Math::floor(line->from.x) + 0.5, Math::floor(line->from.y) + 0.5), + Vector2(Math::floor(line->to.x) + 0.5, Math::floor(line->to.y) + 0.5) }; #ifdef GLES_OVER_GL diff --git a/scene/2d/canvas_item.cpp b/scene/2d/canvas_item.cpp index b38fbfe981f..f2536deaacf 100644 --- a/scene/2d/canvas_item.cpp +++ b/scene/2d/canvas_item.cpp @@ -777,32 +777,32 @@ void CanvasItem::draw_rect(const Rect2 &p_rect, const Color &p_color, bool p_fil VisualServer::get_singleton()->canvas_item_add_line( canvas_item, - p_rect.position + Point2(-offset, 0), + p_rect.position + Size2(-offset, 0), p_rect.position + Size2(p_rect.size.width + offset, 0), p_color, p_width, p_antialiased); VisualServer::get_singleton()->canvas_item_add_line( canvas_item, - p_rect.position + Point2(0, offset), - p_rect.position + Size2(0, p_rect.size.height - offset), - p_color, - p_width, - p_antialiased); - VisualServer::get_singleton()->canvas_item_add_line( - canvas_item, - p_rect.position + Point2(-offset, p_rect.size.height), - p_rect.position + Size2(p_rect.size.width + offset, p_rect.size.height), - p_color, - p_width, - p_antialiased); - VisualServer::get_singleton()->canvas_item_add_line( - canvas_item, - p_rect.position + Point2(p_rect.size.width, offset), + p_rect.position + Size2(p_rect.size.width, offset), p_rect.position + Size2(p_rect.size.width, p_rect.size.height - offset), p_color, p_width, p_antialiased); + VisualServer::get_singleton()->canvas_item_add_line( + canvas_item, + p_rect.position + Size2(p_rect.size.width + offset, p_rect.size.height), + p_rect.position + Size2(-offset, p_rect.size.height), + p_color, + p_width, + p_antialiased); + VisualServer::get_singleton()->canvas_item_add_line( + canvas_item, + p_rect.position + Size2(0, p_rect.size.height - offset), + p_rect.position + Size2(0, offset), + p_color, + p_width, + p_antialiased); } }