Very clean render, with fbo pass, etc etc

lib/app.cpp

@@ -6,28 +6,33 @@
 
 using namespace std;
 
-static std::vector<Vertex> generate_random_points(size_t N){
-	std::vector<Vertex> ret(N);
-
-	const float d = 0.1;
-	for(auto& x : ret){
-		x[0] = d * rand() / float(RAND_MAX);
-		x[1] = d * rand() / float(RAND_MAX);
-		x[2] = d * rand() / float(RAND_MAX);
-	}
-
-	return ret;
-}
-
-enum {
-	POS_ATTR,
-	TEX_ATTR
+// implementation follow later
+static moggle::shader_program create_shader_from_files(std::string vertex, std::string fragment);
+template <typename T>
+static moggle::vbo<T> create_vbo(std::vector<T> const & data);
+static moggle::vao create_vao(moggle::vbo<GLPoint> const & vbo);
+static moggle::vao create_vao(moggle::vbo<Vertex> const & vbo);
+static GLuint create_gl_texture(GLsizei width, GLsizei height);
+static std::vector<GLPoint> generate_random_points(size_t N);
+cl::Context create_shared_cl_context(GLContext & gl_context);
+
+std::vector<Vertex> quad = {
+	{{-1, -1}, {0, 0}},
+	{{ 1, -1}, {1, 0}},
+	{{-1,  1}, {0, 1}},
+	{{ 1,  1}, {1, 1}},
 };
 
+static const GLsizei FBO_SIZE = 1024;
+
 App::App(GLContext& gl_context)
 : gl_vbo(create_vbo(generate_random_points(N)))
 , gl_vao(create_vao(gl_vbo))
-, gl_program(create_shader_from_files("Fractal.vsh", "Fractal.fsh"))
+, gl_quad_vbo(create_vbo(quad))
+, gl_quad_vao(create_vao(gl_quad_vbo))
+, gl_points_program(create_shader_from_files("Points.vsh", "Points.fsh"))
+, gl_texture_program(create_shader_from_files("Texture.vsh", "Texture.fsh"))
+, gl_fbo(moggle::fbo::create_default(FBO_SIZE, FBO_SIZE))
 , cl_context(create_shared_cl_context(gl_context))
 , cl_device(cl_context.getInfo<CL_CONTEXT_DEVICES>().front())
 , cl_queue(cl_context, cl_device)
@@ -40,35 +45,68 @@ App::App(GLContext& gl_context)
 	moggle::gl::enable(GL_BLEND);
 	moggle::gl::blend_function(GL_ONE, GL_ONE);
 	moggle::gl::blend_equation(GL_FUNC_ADD);
+
+	moggle::gl::active_texture(GL_TEXTURE0);
+	moggle::gl::texture_parameter_i(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	moggle::gl::texture_parameter_i(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 }
 
-void App::draw(){
+void App::draw(std::function<void(void)> bind, std::function<void(void)> flush){
 	auto dt = 1/60.0;
 	time += dt;
-	if(wait > 0) wait -= dt;
 
-	if(wait <= 0){
+	// OpenCL update
 	k_update(cl_queue, N, p_s, p_r, p_b, p_dt, cl_buffer);
-	}
-
 	cl::checky(cl_queue.finish());
 
-	moggle::gl::clear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	// OpenGL to fbo
+	gl_fbo.bind();
+	moggle::gl::viewport(0, 0, FBO_SIZE, FBO_SIZE);
 
-	gl_program.use();
+	gl_points_program.use();
 	gl_vao.bind();
-
 	moggle::gl::draw_arrays(GL_POINTS, 0, N);
+
+	// Draw fbo
+	bind();
+	moggle::gl::clear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+	gl_texture_program.use();
+
+	gl_fbo.get_texture().bind(GL_TEXTURE_2D);
+	gl_texture_program.uniform<GLint>("tex").set(0);
+	gl_texture_program.uniform<GLfloat>("maxf").set(maxf);
+
+	gl_quad_vao.bind();
+	moggle::gl::draw_arrays(GL_TRIANGLE_STRIP, 0, 4);
+
+	flush();
 }
 
 void App::resize(size_t w, size_t h){
-	wait = 5;
-
 	W = w;
 	H = h;
 }
 
-moggle::shader_program App::create_shader_from_files(string vertex, string fragment){
+cl::Program App::create_cl_program(string file){
+	cl_int err = 0;
+
+	// build the program
+	cl::Program cl_program(cl_context, slurp(file), true, &err);
+	cout << cl_program.getBuildInfo<CL_PROGRAM_BUILD_LOG>(cl_device) << std::endl;
+
+	cl::checky(err);
+	cout << cl_program << endl;
+
+	return cl_program;
+}
+
+enum {
+	POS_ATTR,
+	TEX_ATTR
+};
+
+moggle::shader_program create_shader_from_files(string vertex, string fragment){
 	moggle::shader_program program;
 
 	auto vs = moggle::shader::from_file(moggle::shader_type::vertex, vertex);
@@ -78,20 +116,22 @@ moggle::shader_program App::create_shader_from_files(string vertex, string fragm
 	program.attach(fs);
 
 	program.bind_attribute(POS_ATTR, "position");
+	program.bind_attribute(TEX_ATTR, "tex_coord");
 
 	program.link();
 
 	return program;
 }
 
-moggle::vbo<Vertex> App::create_vbo(const std::vector<Vertex>& data){
-	moggle::vbo<Vertex> vbo;
+template <typename T>
+moggle::vbo<T> create_vbo(const std::vector<T>& data){
+	moggle::vbo<T> vbo;
 	vbo.bind(GL_ARRAY_BUFFER);
 	vbo.data(data);
 	return vbo;
 }
 
-moggle::vao App::create_vao(const moggle::vbo<Vertex>& vbo){
+moggle::vao create_vao(const moggle::vbo<GLPoint>& vbo){
 	moggle::vao vao;
 	vao.bind();
 
@@ -102,18 +142,41 @@ moggle::vao App::create_vao(const moggle::vbo<Vertex>& vbo){
 	return vao;
 }
 
-GLuint App::create_gl_texture(GLsizei width, GLsizei height){
+moggle::vao create_vao(const moggle::vbo<Vertex>& vbo){
+	moggle::vao vao;
+	vao.bind();
+
+	moggle::gl::enable_vertex_attribute_array(POS_ATTR);
+	moggle::gl::enable_vertex_attribute_array(TEX_ATTR);
+
+	vao.attribute(POS_ATTR, vbo, &Vertex::pos);
+	vao.attribute(TEX_ATTR, vbo, &Vertex::tex);
+
+	return vao;
+}
+
+GLuint create_gl_texture(GLsizei width, GLsizei height){
 	GLuint tex = 0;
-	moggle::gl::active_texture(GL_TEXTURE0);
 	moggle::gl::generate_textures(1, &tex);
 	moggle::gl::bind_texture(GL_TEXTURE_2D, tex);
 	moggle::gl::texture_image_2d(GL_TEXTURE_2D, 0, GL_RGBA32F, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
-	moggle::gl::texture_parameter_i(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-	moggle::gl::texture_parameter_i(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 	return tex;
 }
 
-cl::Context App::create_shared_cl_context(GLContext& gl_context){
+static std::vector<GLPoint> generate_random_points(size_t N){
+	std::vector<GLPoint> ret(N);
+
+	const auto d = 2.0;
+	for(auto& x : ret){
+		x[0] = d * rand() / float(RAND_MAX) - 0.5*d;
+		x[1] = d * rand() / float(RAND_MAX) - 0.5*d;
+		x[2] = d * rand() / float(RAND_MAX) - 0.5*d;
+	}
+
+	return ret;
+}
+
+cl::Context create_shared_cl_context(GLContext& gl_context){
 	CGLShareGroupObj sharegroup = CGLGetShareGroup(gl_context.ctx);
 
 	cl_context_properties properties[] = {
@@ -127,16 +190,3 @@ cl::Context App::create_shared_cl_context(GLContext& gl_context){
 
 	return cl_context;
 }
-
-cl::Program App::create_cl_program(string file){
-	cl_int err = 0;
-
-	// build the program
-	cl::Program cl_program(cl_context, slurp(file), true, &err);
-	cout << cl_program.getBuildInfo<CL_PROGRAM_BUILD_LOG>(cl_device) << std::endl;
-
-	cl::checky(err);
-	cout << cl_program << endl;
-
-	return cl_program;
-}

lib/app.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "fbo.hpp"
 #include <moggle/core/gl.hpp>
 #include <moggle/core/shader.hpp>
 #include <moggle/core/vao.hpp>
@@ -8,27 +9,38 @@
 #include <cl2.hpp>
 #include <NSGLWrapper.hpp>
 
-using Vertex = moggle::hvector4<GLfloat>;
+// Used for the bare points
+using GLPoint = moggle::hvector4<GLfloat>;
+
+// Used for rendering a textured quad
+struct Vertex {
+	moggle::vector2<GLfloat> pos;
+	moggle::vector2<GLfloat> tex;
+};
 
 struct App {
 	size_t W = 128;
 	size_t H = 128;
-	size_t N = 1 << 20;
+	size_t N = 1 << 18;
 	float time = 0;
-	float wait = 5;
 	float p_s = 10.962073;
 	float p_r = 31.211250;
 	float p_b = 1.537946;
 	float p_dt = 0.013040;
+	float maxf = 500;
 
 	App(GLContext & gl_context);
-	void draw();
+	void draw(std::function<void(void)> bind, std::function<void(void)> flush);
 	void resize(size_t w, size_t h);
 
 private:
-	moggle::vbo<Vertex> gl_vbo;
+	moggle::vbo<GLPoint> gl_vbo;
 	moggle::vao gl_vao;
-	moggle::shader_program gl_program;
+	moggle::vbo<Vertex> gl_quad_vbo;
+	moggle::vao gl_quad_vao;
+	moggle::shader_program gl_points_program;
+	moggle::shader_program gl_texture_program;
+	moggle::fbo gl_fbo;
 
 	cl::Context cl_context;
 	cl::Device cl_device;
@@ -37,10 +49,5 @@ private:
 	cl::Program cl_program;
 	KernelOp k_update;
 
-	static moggle::shader_program create_shader_from_files(std::string vertex, std::string fragment);
-	static moggle::vbo<Vertex> create_vbo(std::vector<Vertex> const & data);
-	static moggle::vao create_vao(moggle::vbo<Vertex> const & vbo);
-	static GLuint create_gl_texture(GLsizei width, GLsizei height);
-	static cl::Context create_shared_cl_context(GLContext & gl_context);
 	cl::Program create_cl_program(std::string file);
 };

lib/fbo.hpp

@@ -0,0 +1,91 @@
+#pragma once
+
+#include <moggle/core/gl.hpp>
+#include "renderbuffer.hpp"
+#include "texture.hpp"
+
+#include <vector>
+
+/*
+ * One can attach either an external renderbuffer/texture, or move one into fbo
+ * In the latter case, the fbo will own the renderbuffer/texture
+ *
+ * Attachment can be one of: GL_COLOR_ATTACHMENT0, GL_DEPTH_ATTACHMENT, or GL_STENCIL_ATTACHMENT
+ */
+
+namespace moggle {
+
+struct fbo {
+	explicit fbo(bool create_now = false) {
+		if(create_now) create();
+	}
+
+	~fbo() { destroy(); }
+
+	fbo(fbo const &) = delete;
+	fbo & operator=(fbo const&) = delete;
+
+	fbo(fbo && r) : id(r.id) { r.id = 0; }
+	fbo & operator=(fbo && r) { std::swap(id, r.id); return *this; }
+
+	bool created() const { return id; }
+	explicit operator bool() const { return created(); }
+
+	void create(){ if(!id) gl::generate_framebuffers(1, &id); }
+	void destroy(){ gl::delete_renderbuffers(1, &id); id = 0; }
+
+	void bind() {
+		create();
+		gl::bind_framebuffer(GL_FRAMEBUFFER, id);
+	}
+
+	GLuint get_id() const {
+		return id;
+	}
+
+	// Only well defined if the fbo owns the texture
+	texture & get_texture() {
+		return textures.front();
+	}
+
+	void attach(GLenum attachment, renderbuffer const & rb){
+		bind();
+		gl::framebuffer_renderbuffer(GL_FRAMEBUFFER, attachment, GL_RENDERBUFFER, rb.get_id());
+	}
+
+	void attach(GLenum attachment, renderbuffer && rb){
+		renderbuffers.push_back(std::move(rb));
+		attach(attachment, renderbuffers.back());
+	}
+
+	void attach(GLenum attachment, GLenum textarget, texture const & t){
+		bind();
+		gl::framebuffer_texture_2d(GL_FRAMEBUFFER, attachment, textarget, t.get_id(), 0);
+	}
+
+	void attach(GLenum attachment, GLenum textarget, texture && t){
+		textures.push_back(std::move(t));
+		attach(attachment, textarget, textures.back());
+	}
+
+	void clear(GLenum bufferbits){
+		bind();
+		gl::clear(bufferbits);
+	}
+
+	static fbo create_default(GLsizei width, GLsizei height){
+		fbo f;
+		f.attach(GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture::create(width, height, GL_RGBA32F));
+		f.attach(GL_DEPTH_ATTACHMENT, renderbuffer::create(width, height, 1, GL_DEPTH_COMPONENT16));
+		f.clear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		return f;
+	}
+
+private:
+	std::vector<renderbuffer> renderbuffers;
+	std::vector<texture> textures;
+
+	GLuint id = 0;
+};
+
+}

lib/renderbuffer.hpp

@@ -0,0 +1,57 @@
+#pragma once
+
+#include <moggle/core/gl.hpp>
+
+namespace moggle {
+
+struct renderbuffer {
+	explicit renderbuffer(bool create_now = false) {
+		if(create_now) create();
+	}
+
+	~renderbuffer() { destroy(); }
+
+	renderbuffer(renderbuffer const &) = delete;
+	renderbuffer & operator=(renderbuffer const&) = delete;
+
+	renderbuffer(renderbuffer && r) : id(r.id) { r.id = 0; }
+	renderbuffer & operator=(renderbuffer && r) { std::swap(id, r.id); return *this; }
+
+	bool created() const { return id; }
+	explicit operator bool() const { return created(); }
+
+	void create(){ if(!id) gl::generate_renderbuffers(1, &id); }
+	void destroy(){ gl::delete_renderbuffers(1, &id); id = 0; }
+
+	void bind() {
+		create();
+		gl::bind_renderbuffer(GL_RENDERBUFFER, id);
+	}
+
+	GLuint get_id() const {
+		return id;
+	}
+
+	void storage(GLenum target, GLenum internalformat, GLsizei width, GLsizei height){
+		bind();
+		gl::renderbuffer_storage(target, internalformat, width, height);
+	}
+
+	void storage_multisample(GLenum target, GLsizei samples, GLenum internalformat, GLsizei width, GLsizei height){
+		bind();
+		// TODO: wrap this call
+		glRenderbufferStorageMultisample(target, samples, internalformat, width, height);
+	}
+
+	static renderbuffer create(GLsizei width, GLsizei height, GLsizei samples = 1, GLenum format = GL_RGBA4){
+		renderbuffer r;
+		if(samples <= 1) r.storage(GL_RENDERBUFFER, format, width, height);
+		else r.storage_multisample(GL_RENDERBUFFER, samples, format, width, height);
+		return r;
+	}
+
+private:
+	GLuint id = 0;
+};
+
+}

lib/texture.hpp

@@ -0,0 +1,62 @@
+#pragma once
+
+#include <moggle/core/gl.hpp>
+#include <moggle/core/gl_type_traits.hpp>
+
+/*
+ * NOTE:
+ * in glTexImage2D, border MUST be 0, so this parameter is left out in this interface.
+ */
+
+namespace moggle {
+
+struct texture {
+	explicit texture(bool create_now = false) {
+		if(create_now) create();
+	}
+
+	~texture() { destroy(); }
+
+	texture(texture const &) = delete;
+	texture & operator=(texture const&) = delete;
+
+	texture(texture && t) : id(t.id) { t.id = 0; }
+	texture & operator=(texture && t) { std::swap(id, t.id); return *this; }
+
+	bool created() const { return id; }
+	explicit operator bool() const { return created(); }
+
+	void create(){ if(!id) gl::generate_textures(1, &id); }
+	void destroy(){ gl::delete_textures(1, &id); id = 0; }
+
+	void bind(GLenum target) {
+		create();
+		gl::bind_texture(target, id);
+	}
+
+	GLuint get_id() const { return id; }
+
+	template <typename T>
+	void image_2d(GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, GLenum format, const T * data){
+		bind(target);
+		auto type = gl_type_traits<T>::gl_constant;
+		gl::texture_image_2d(target, level, internalformat, width, height, 0, format, type, data);
+	}
+
+	void image_2d(GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, std::nullptr_t){
+		bind(target);
+		gl::texture_image_2d(target, level, internalformat, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
+	}
+
+	//! creates empty texture
+	static texture create(GLsizei width, GLsizei height, GLint internalformat = GL_RGBA, GLenum target = GL_TEXTURE_2D){
+		texture t;
+		t.image_2d(target, 0, internalformat, width, height, nullptr);
+		return t;
+	}
+
+private:
+	GLuint id = 0;
+};
+
+}

resources/Fractal.vsh → resources/Points.vsh

@@ -6,5 +6,5 @@ out float mx;
 void main(){
 	gl_Position = vec4(1);
 	gl_Position.xy = 0.04*position.xy;
-	mx = cos(0.1*position.z);
+	mx = cos(0.1337*position.z);
 }

resources/Texture.fsh

@@ -0,0 +1,12 @@
+#version 330
+
+uniform sampler2D tex;
+uniform float maxf;
+
+in vec2 tex_coord_;
+
+out vec4 fragColor;
+
+void main(){
+	fragColor = sqrt(texture(tex, tex_coord_) / maxf);
+}

resources/Texture.vsh

@@ -0,0 +1,11 @@
+#version 330
+
+in vec4 position;
+in vec2 tex_coord;
+
+out vec2 tex_coord_;
+
+void main(){
+	gl_Position = position;
+	tex_coord_ = tex_coord;
+}

src/main.cpp

@@ -14,8 +14,8 @@ int main() {
 		[&](ContextParameters ctxp){
 			a = make_unique<App>(ctxp.context);
 		},
-		[&](ContextParameters){
-			a->draw();
+		[&](ContextParameters ctxp){
+			a->draw(ctxp.bind_framebuffer, ctxp.flush_drawable);
 		},
 		[&](ContextParameters, CGFloat w, CGFloat h){
 			a->resize(size_t(floor(w)), size_t(floor(h)));
@@ -30,7 +30,8 @@ int main() {
 		{"s", 10.962073, 9, 13,        [&](double x){ a->p_s = x; }},
 		{"r", 31.211250, 30, 32,       [&](double x){ a->p_r = x; }},
 		{"b", 1.537946, 0.0001, 3,     [&](double x){ a->p_b = x; }},
-		{"dt", 0.013040, 0.0001, 0.03, [&](double x){ a->p_dt = x; }}
+		{"dt", 0.013040, 0.0001, 0.03, [&](double x){ a->p_dt = x; }},
+		{"max", 500, 0.1, 50000,       [&](double x){ a->maxf = x; }},
 	}});
 
 	app.run();