1 files changed, 144 insertions, 0 deletions
diff --git a/util/ogl_renderer/c++/state.hpp b/util/ogl_renderer/c++/state.hpp
new file mode 100644
index 0000000..c429195
--- /dev/null
+++ b/util/ogl_renderer/c++/state.hpp
@@ -0,0 +1,144 @@
+#pragma once
+
+#include "common.hpp"
+#include "program.hpp"
+
+#include "shaders/basic.hpp"
+
+namespace kel {
+namespace lbm {
+namespace sch {
+using namespace saw::schema;
+}
+
+struct ogl_state final {
+public:
+	SDL_Window* window;
+	SDL_GLContext context;
+	int version;
+	GLuint vao_id;
+	GLuint vbo_id;
+	GLuint veo_id;
+
+	GLuint program_id;
+	GLuint fbo_id;
+	GLuint tex_id;
+
+	uint64_t w, h;
+
+public:
+	ogl_state():
+		window{nullptr},
+		version{0},
+		vao_id{0u},
+		vbo_id{0u},
+		program_id{0u},
+		fbo_id{0u},
+		tex_id{0u},
+		w{1024},
+		h{1024}
+	{
+		SDL_Init(SDL_INIT_VIDEO);
+	}
+
+	~ogl_state(){
+		SDL_GL_DestroyContext(context);
+		if(window){
+			SDL_DestroyWindow(window);
+			window = nullptr;
+		}
+		SDL_Quit();
+	}
+
+	void clear(){
+		glClear(GL_COLOR_BUFFER_BIT);
+	}
+};
+
+saw::error_or<saw::own<ogl_state>> create_ogl_renderer(){
+	auto owned_state = saw::heap<ogl_state>();
+
+	auto& st = *owned_state;
+
+	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION,3);
+	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION,3);
+	SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
+
+	st.window = SDL_CreateWindow("Kel'LBM Renderer",st.w,st.h,SDL_WINDOW_OPENGL /*| SDL_WINDOW_HIDDEN*/);
+	if(not st.window){
+		return saw::make_error<saw::err::critical>("Window not created");
+	}
+	st.context = SDL_GL_CreateContext(st.window);
+
+	st.version = gladLoadGL((GLADloadfunc)SDL_GL_GetProcAddress);
+	glGenVertexArrays(1,&st.vao_id);
+	glBindVertexArray(st.vao_id);
+	glClearColor(0.0,0.0,0.0,1.0);
+
+	glGenBuffers(1,&st.vbo_id);
+	glGenBuffers(1,&st.veo_id);
+	static constexpr GLfloat vertex_buffer_data[] = {
+		-1.f, -1.f, 0.f, 0.f,
+		 1.f, -1.f, 1.f, 0.f,
+		 1.f,  1.f, 1.f, 1.f,
+		-1.f,  1.f, 0.f, 1.f
+	};
+	static unsigned int index_buffer_data[] = {
+		0, 1, 2,
+		2, 3, 0
+	};
+	glBindBuffer(GL_ARRAY_BUFFER, st.vbo_id);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_buffer_data), vertex_buffer_data, GL_STATIC_DRAW);
+
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, st.veo_id);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(index_buffer_data), index_buffer_data, GL_STATIC_DRAW);
+
+	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(GLfloat), 0);
+	glEnableVertexAttribArray(0);
+
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(GLfloat), (void*)(2 * sizeof(GLfloat)));
+	glEnableVertexAttribArray(1);
+
+	glGenFramebuffers(1,&st.fbo_id);
+	//glBindFramebuffer(GL_FRAMEBUFFER, st.fbo_id);
+
+	glGenTextures(1,&st.tex_id);
+	glBindTexture(GL_TEXTURE_2D,st.tex_id);
+
+	glTexImage2D(
+		GL_TEXTURE_2D,
+		0,
+		GL_RGBA,
+		1024,
+		1024,
+		0,
+		GL_RGBA,
+		GL_UNSIGNED_BYTE,
+		NULL
+	);
+
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+	glFramebufferTexture2D(
+		GL_FRAMEBUFFER,
+		GL_COLOR_ATTACHMENT0,
+		GL_TEXTURE_2D,
+		st.tex_id,
+		0
+	);
+
+	glViewport(0,0,1024,1024);
+	st.program_id = create_ogl_program(shader_basic_vertex.data(), shader_basic_fragment.data());
+	glUseProgram(st.program_id);
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_2D, st.tex_id);
+
+	glUniform1i(glGetUniformLocation(st.program_id, "tex_sampler"), 0);
+	st.clear();
+
+	return owned_state;
+}
+}
+}