From fec050307d83ffaaa85d6496c65185b163c594f6 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Fri, 5 Mar 2021 23:13:27 +0300
Subject: [PATCH] Add triangle painting to ui::painter

---
 libs/ui/include/psemek/ui/painter.hpp      |  2 ++
 libs/ui/include/psemek/ui/painter_impl.hpp |  1 +
 libs/ui/source/painter_impl.cpp            | 14 ++++++++++++++
 3 files changed, 17 insertions(+)

diff --git a/libs/ui/include/psemek/ui/painter.hpp b/libs/ui/include/psemek/ui/painter.hpp
index 6a50cb3d..cd031dd8 100644
--- a/libs/ui/include/psemek/ui/painter.hpp
+++ b/libs/ui/include/psemek/ui/painter.hpp
@@ -4,6 +4,7 @@
 #include <psemek/gfx/color.hpp>
 #include <psemek/gfx/texture.hpp>
 #include <psemek/geom/box.hpp>
+#include <psemek/geom/simplex.hpp>
 
 namespace psemek::ui
 {
@@ -11,6 +12,7 @@ namespace psemek::ui
 	struct painter
 	{
 		virtual void draw_rect(geom::box<float, 2> const & rect, gfx::color_rgba const & color) = 0;
+		virtual void draw_triangle(geom::triangle<geom::point<float, 2>> const & tri, gfx::color_rgba const & color) = 0;
 		virtual void draw_glyph(font const & f, char32_t c, geom::box<float, 2> const & rect, gfx::color_rgba const & color) = 0;
 		virtual void draw_image(geom::box<float, 2> const & rect, gfx::texture_2d const & tex, gfx::color_rgba const & color = {0, 0, 0, 0}) = 0;
 		virtual void draw_subimage(geom::box<float, 2> const & rect, gfx::texture_2d const & tex, geom::box<float, 2> const & part, gfx::color_rgba const & color = {0, 0, 0, 0}) = 0;
diff --git a/libs/ui/include/psemek/ui/painter_impl.hpp b/libs/ui/include/psemek/ui/painter_impl.hpp
index 34c33b1b..d0319edc 100644
--- a/libs/ui/include/psemek/ui/painter_impl.hpp
+++ b/libs/ui/include/psemek/ui/painter_impl.hpp
@@ -16,6 +16,7 @@ namespace psemek::ui
 		~painter_impl();
 
 		void draw_rect(geom::box<float, 2> const & rect, gfx::color_rgba const & color) override;
+		void draw_triangle(geom::triangle<geom::point<float, 2>> const & tri, gfx::color_rgba const & color) override;
 		void draw_glyph(font const & f, char32_t c, geom::box<float, 2> const & rect, gfx::color_rgba const & color) override;
 		void draw_image(geom::box<float, 2> const & rect, gfx::texture_2d const & tex, gfx::color_rgba const & color) override;
 		void draw_subimage(geom::box<float, 2> const & rect, gfx::texture_2d const & tex, geom::box<float, 2> const & part, gfx::color_rgba const & color = {0, 0, 0, 0}) override;
diff --git a/libs/ui/source/painter_impl.cpp b/libs/ui/source/painter_impl.cpp
index 04aefeec..e3f5d78b 100644
--- a/libs/ui/source/painter_impl.cpp
+++ b/libs/ui/source/painter_impl.cpp
@@ -249,6 +249,20 @@ void main()
 		batch.indices.insert(batch.indices.end(), {base + 0, base + 1, base + 2, base + 2, base + 1, base + 3});
 	}
 
+	void painter_impl::draw_triangle(geom::triangle<geom::point<float, 2>> const & tri, gfx::color_rgba const & color)
+	{
+		auto & batch = impl().batch<colored_batch>({});
+
+		std::uint32_t const depth = impl().depth++;
+		std::uint32_t const base = batch.vertices.size();
+
+		batch.vertices.push_back({tri[0], depth, color});
+		batch.vertices.push_back({tri[1], depth, color});
+		batch.vertices.push_back({tri[2], depth, color});
+
+		batch.indices.insert(batch.indices.end(), {base + 0, base + 1, base + 2});
+	}
+
 	void painter_impl::draw_glyph(font const & f, char32_t c, geom::box<float, 2> const & rect, gfx::color_rgba const & color)
 	{
 		auto tbox = f.texcoords(c);