Add a simple colored renderer

libs/gfx/include/psemek/gfx/renderer/simple.hpp

@@ -0,0 +1,54 @@
+#pragma once
+
+#include <psemek/gfx/drawable.hpp>
+#include <psemek/gfx/color.hpp>
+#include <psemek/geom/matrix.hpp>
+
+#include <vector>
+#include <memory>
+
+namespace psemek::gfx
+{
+
+	struct simple_renderer
+	{
+		// Attributes:
+		// 0: vec3 position
+		// 1: vec4 color (if uniform color is not set)
+
+		struct render_state
+		{
+			drawable const * mesh = nullptr;
+			std::optional<color_rgba> color;
+		};
+
+		struct render_object
+		{
+			virtual std::vector<render_state> get_render_states() = 0;
+
+			virtual ~render_object() {}
+		};
+
+		struct render_options
+		{
+			geom::matrix<float, 4, 4> transform;
+		};
+
+		simple_renderer();
+		~simple_renderer();
+
+		void add(render_object * o);
+		void remove(render_object * o);
+
+		void push(render_state s);
+
+		void render(render_options const & opts);
+
+	private:
+		struct impl;
+		std::unique_ptr<struct impl> pimpl_;
+		struct impl & impl() { return *pimpl_; }
+		struct impl const & impl() const { return *pimpl_; }
+	};
+
+}

libs/gfx/source/renderer/simple.cpp

@@ -0,0 +1,129 @@
+#include <psemek/gfx/renderer/simple.hpp>
+
+#include <psemek/gfx/program.hpp>
+
+namespace psemek::gfx
+{
+
+	static char const attrib_color_vertex_source[] =
+R"(#version 330
+
+uniform mat4 u_transform;
+
+layout (location = 0) in vec4 in_position;
+layout (location = 1) in vec4 in_color;
+
+out vec4 color;
+
+void main()
+{
+	gl_Position = u_transform * in_position;
+	color = in_color;
+}
+)";
+
+	static char const uniform_color_vertex_source[] =
+R"(#version 330
+
+uniform mat4 u_transform;
+uniform vec4 u_color;
+
+layout (location = 0) in vec4 in_position;
+
+out vec4 color;
+
+void main()
+{
+	gl_Position = u_transform * in_position;
+	color = u_color;
+}
+)";
+
+	static char const fragment_source[] =
+R"(#version 330
+
+in vec4 color;
+out vec4 out_color;
+
+void main()
+{
+	out_color = color;
+}
+)";
+
+	struct simple_renderer::impl
+	{
+		program attrib_color_program{attrib_color_vertex_source, fragment_source};
+		program uniform_color_program{uniform_color_vertex_source, fragment_source};
+
+		std::vector<render_object *> objects;
+		std::vector<render_state> attrib_color_states;
+		std::vector<render_state> uniform_color_states;
+	};
+
+	simple_renderer::simple_renderer()
+		: pimpl_{std::make_unique<struct impl>()}
+	{}
+
+	simple_renderer::~simple_renderer() = default;
+
+	void simple_renderer::add(render_object * o)
+	{
+		impl().objects.push_back(o);
+	}
+
+	void simple_renderer::remove(render_object * o)
+	{
+		auto it = std::find(impl().objects.begin(), impl().objects.end(), o);
+		if (it != impl().objects.end())
+			impl().objects.erase(it);
+	}
+
+	void simple_renderer::push(render_state s)
+	{
+		if (s.mesh)
+		{
+			if (s.color)
+				impl().uniform_color_states.push_back(s);
+			else
+				impl().attrib_color_states.push_back(s);
+		}
+	}
+
+	void simple_renderer::render(render_options const & opts)
+	{
+		for (auto o : impl().objects)
+		{
+			for (auto const & s : o->get_render_states())
+				push(s);
+		}
+
+		if (!impl().attrib_color_states.empty())
+		{
+			impl().attrib_color_program.bind();
+			impl().attrib_color_program["u_transform"] = opts.transform;
+
+			for (auto const & s : impl().attrib_color_states)
+			{
+				s.mesh->draw();
+			}
+
+			impl().attrib_color_states.clear();
+		}
+
+		if (!impl().uniform_color_states.empty())
+		{
+			impl().uniform_color_program.bind();
+			impl().uniform_color_program["u_transform"] = opts.transform;
+
+			for (auto const & s : impl().uniform_color_states)
+			{
+				impl().uniform_color_program["u_color"] = to_colorf(*s.color);
+				s.mesh->draw();
+			}
+
+			impl().uniform_color_states.clear();
+		}
+	}
+
+}