From 91650cb4ac459da359b5caba52cd70e69dcac353 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Thu, 10 Dec 2020 23:33:25 +0300
Subject: [PATCH] gfx::texture::pixels: support different lods & outputting to
 existing pixmap

---
 libs/gfx/include/psemek/gfx/texture.hpp | 26 +++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/libs/gfx/include/psemek/gfx/texture.hpp b/libs/gfx/include/psemek/gfx/texture.hpp
index 66db3828..b6ec4956 100644
--- a/libs/gfx/include/psemek/gfx/texture.hpp
+++ b/libs/gfx/include/psemek/gfx/texture.hpp
@@ -47,10 +47,13 @@ namespace psemek::gfx
 		template <typename Pixel>
 		void load(util::array<Pixel, D> const & p);
 
-		void pixels(GLenum format, GLenum type, void * data) const;
+		void pixels(GLenum format, GLenum type, void * data, int layer = 0) const;
 
 		template <typename Pixmap>
-		Pixmap pixels() const;
+		void pixels(Pixmap & pixmap, int layer = 0) const;
+
+		template <typename Pixmap>
+		Pixmap pixels(int layer = 0) const;
 
 		static basic_texture from_data(GLint internal_format, geom::vector<std::size_t, D> const & size, GLenum format, GLenum type, const void * data);
 
@@ -268,24 +271,31 @@ namespace psemek::gfx
 	}
 
 	template <std::size_t D, GLenum Target>
-	void basic_texture<D, Target>::pixels(GLenum format, GLenum type, void * data) const
+	void basic_texture<D, Target>::pixels(GLenum format, GLenum type, void * data, int layer) const
 	{
 		bind();
-		gl::GetTexImage(Target, 0, format, type, data);
+		gl::GetTexImage(Target, layer, format, type, data);
 	}
 
 	template <std::size_t D, GLenum Target>
 	template <typename Pixmap>
-	Pixmap basic_texture<D, Target>::pixels() const
+	void basic_texture<D, Target>::pixels(Pixmap & pixmap, int layer) const
 	{
 		using traits = pixel_traits<typename Pixmap::value_type>;
 
 		std::array<std::size_t, D> size;
 		for (std::size_t i = 0; i < D; ++i) size[i] = size_[i];
+		pixmap.resize(size);
+		pixels(traits::format, traits::type, pixmap.data(), layer);
+	}
 
-		Pixmap p(size);
-		pixels(traits::format, traits::type, p.data());
-		return p;
+	template <std::size_t D, GLenum Target>
+	template <typename Pixmap>
+	Pixmap basic_texture<D, Target>::pixels(int layer) const
+	{
+		Pixmap pixmap;
+		pixels(pixmap, layer);
+		return pixmap;
 	}
 
 	template <std::size_t D, GLenum Target>