Support image rendering in ui::painter

libs/ui/include/psemek/ui/painter.hpp

@@ -2,6 +2,7 @@
 
 #include <psemek/ui/font.hpp>
 #include <psemek/gfx/color.hpp>
+#include <psemek/gfx/texture.hpp>
 #include <psemek/geom/box.hpp>
 
 namespace psemek::ui
@@ -11,6 +12,7 @@ namespace psemek::ui
 	{
 		virtual void draw_rect(geom::box<float, 2> const & rect, 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 ~painter() {}
 	};

libs/ui/include/psemek/ui/painter_impl.hpp

@@ -17,6 +17,7 @@ namespace psemek::ui
 
 		void draw_rect(geom::box<float, 2> const & rect, 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 render(geom::matrix<float, 4, 4> const & transform);
 

libs/ui/source/painter_impl.cpp

@@ -39,6 +39,45 @@ void main()
 {
 	out_color = color;
 }
+)";
+
+	static char const bitmap_text_vs[] =
+R"(#version 330
+
+uniform mat4 u_transform;
+
+uniform vec2 u_atlas_size;
+
+layout (location = 0) in vec2 in_position;
+layout (location = 1) in float in_depth;
+layout (location = 2) in vec4 in_color;
+layout (location = 3) in vec2 in_texcoord;
+
+out vec4 color;
+out vec2 texcoord;
+
+void main()
+{
+	gl_Position = u_transform * vec4(in_position, 1.0 - float(in_depth) / 16777216.0 * 2.0, 1.0);
+	color = in_color;
+	texcoord = in_texcoord / u_atlas_size;
+}
+)";
+
+	static char const bitmap_text_fs[] =
+R"(#version 330
+
+uniform sampler2D u_atlas;
+
+in vec2 texcoord;
+in vec4 color;
+
+out vec4 out_color;
+
+void main()
+{
+	out_color = vec4(color.rgb, texture(u_atlas, texcoord) * color.a);
+}
 )";
 
 	static char const textured_vs[] =
@@ -76,7 +115,7 @@ out vec4 out_color;
 
 void main()
 {
-	out_color = texture(u_texture, texcoord) * color;
+	out_color = mix(texture(u_texture, texcoord), color, color.a);
 }
 )";
 
@@ -109,6 +148,18 @@ void main()
 	};
 	static_assert(sizeof(textured_vertex) == 20);
 
+	struct bitmap_text_batch
+	{
+		gfx::texture_2d const * atlas = nullptr;
+		std::vector<textured_vertex> vertices{};
+		std::vector<std::uint32_t> indices{};
+	};
+
+	bool operator == (bitmap_text_batch const & b1, bitmap_text_batch const & b2)
+	{
+		return b1.atlas == b2.atlas;
+	}
+
 	struct textured_batch
 	{
 		gfx::texture_2d const * texture = nullptr;
@@ -128,10 +179,13 @@ void main()
 		gfx::program colored_program;
 		gfx::mesh colored_mesh;
 
+		gfx::program bitmap_text_program;
+		gfx::mesh bitmap_text_mesh;
+
 		gfx::program textured_program;
 		gfx::mesh textured_mesh;
 
-		std::vector<std::variant<colored_batch, textured_batch>> batches;
+		std::vector<std::variant<colored_batch, bitmap_text_batch, textured_batch>> batches;
 
 		template <typename Batch>
 		Batch & batch(Batch && n)
@@ -151,12 +205,17 @@ void main()
 
 	painter_impl::impl::impl()
 		: colored_program{colored_vs, colored_fs}
+		, bitmap_text_program{bitmap_text_vs, bitmap_text_fs}
 		, textured_program{textured_vs, textured_fs}
 	{
+		bitmap_text_program.bind();
+		bitmap_text_program["u_atlas"] = 0;
+
 		textured_program.bind();
 		textured_program["u_texture"] = 0;
 
 		colored_mesh.setup<geom::point<float, 2>, std::uint32_t, gfx::normalized<gfx::color_rgba>>();
+		bitmap_text_mesh.setup<geom::point<float, 2>, std::uint32_t, gfx::normalized<gfx::color_rgba>, geom::vector<std::uint16_t, 2>>();
 		textured_mesh.setup<geom::point<float, 2>, std::uint32_t, gfx::normalized<gfx::color_rgba>, geom::vector<std::uint16_t, 2>>();
 	}
 
@@ -197,7 +256,7 @@ void main()
 			return r;
 		};
 
-		auto & batch = impl().batch<textured_batch>(textured_batch{&f.atlas()});
+		auto & batch = impl().batch<bitmap_text_batch>(bitmap_text_batch{&f.atlas()});
 
 		std::uint32_t const depth = impl().depth++;
 		std::uint32_t const base = batch.vertices.size();
@@ -210,6 +269,23 @@ void main()
 		batch.indices.insert(batch.indices.end(), {base + 0, base + 1, base + 2, base + 2, base + 1, base + 3});
 	}
 
+	void painter_impl::draw_image(geom::box<float, 2> const & rect, gfx::texture_2d const & tex, gfx::color_rgba const & color)
+	{
+		auto & batch = impl().batch<textured_batch>(textured_batch{&tex});
+
+		std::uint32_t const depth = impl().depth++;
+		std::uint32_t const base = batch.vertices.size();
+
+		auto const size = tex.size();
+
+		batch.vertices.push_back({rect.corner(0.f, 0.f), depth, color, {0, 0}});
+		batch.vertices.push_back({rect.corner(1.f, 0.f), depth, color, {size[0], 0}});
+		batch.vertices.push_back({rect.corner(0.f, 1.f), depth, color, {0, size[1]}});
+		batch.vertices.push_back({rect.corner(1.f, 1.f), depth, color, {size[0], size[1]}});
+
+		batch.indices.insert(batch.indices.end(), {base + 0, base + 1, base + 2, base + 2, base + 1, base + 3});
+	}
+
 	void painter_impl::render(geom::matrix<float, 4, 4> const & transform)
 	{
 		impl().colored_program.bind();
@@ -224,6 +300,14 @@ void main()
 			impl().colored_mesh.load(b.vertices, b.indices, gl::TRIANGLES);
 			impl().colored_mesh.draw();
 		},
+		[&](bitmap_text_batch const & b){
+			if (!b.atlas) return;
+			impl().bitmap_text_program.bind();
+			impl().bitmap_text_program["u_atlas_size"] = geom::cast<float>(b.atlas->size());
+			b.atlas->bind();
+			impl().bitmap_text_mesh.load(b.vertices, b.indices, gl::TRIANGLES);
+			impl().bitmap_text_mesh.draw();
+		},
 		[&](textured_batch const & b){
 			if (!b.texture) return;
 			impl().textured_program.bind();