path: root/advanced_lighting/9.ssao/ssao.c

#include "GL/glew.h"
#include "GLFW/glfw3.h"

#include "pwyazh.h"
#include "pwyazh_GL.h"

#include "xoshiro128plus.c"

#include "common.h"

#include "assert.h"

int main(void)
{
    // glfw init
    glfwSetErrorCallback(error_callback);
    if (glfwInit() == GLFW_FALSE)
        return 1;
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
    S32 width = 1600;
    S32 height = 900;
    GLFWwindow *window = glfwCreateWindow(width, height, "ssao", 0, 0);
    if (!window)
        return 1;
    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
    glfwMakeContextCurrent(window);
    if (glewInit() != GLEW_OK)
        return 1;
    glEnable(GL_DEPTH_TEST);

    // program init
    Arena *arena = arena_alloc(Kilobytes(256));
    Input input = input_init();
    Camera camera = {
        .pos = v3f(0.0f, 2.0f, 5.0f),
        .fovx = 90.0f,
        .near = 0.1f,
        .far = 100.0f,
        .yaw = 0.0f,
        .pitch = 0.0f
    };
    V3F camera_dp = {0};
    light_t light = {{2.0f, 2.0f, 2.0f}, {5.0f, 5.0f, 10.0f}};

    // meshes
    Mesh *quad = mesh_gen_quad(arena);
    Mesh *cube = mesh_load_obj(arena, "../../data/models/cube.obj");

    // framebuffers
    U32 gbuffer;
    glGenFramebuffers(1, &gbuffer);
    glBindFramebuffer(GL_FRAMEBUFFER, gbuffer);

    U32 gpositions;
    glGenTextures(1, &gpositions);
    glBindTexture(GL_TEXTURE_2D, gpositions);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, width, height, 0, GL_RGBA, GL_FLOAT, 0);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, gpositions, 0);

    U32 gnormals;
    glGenTextures(1, &gnormals);
    glBindTexture(GL_TEXTURE_2D, gnormals);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, width, height, 0, GL_RGBA, GL_FLOAT, 0);
    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_ATTACHMENT1, GL_TEXTURE_2D, gnormals, 0);

    U32 galbedo;
    glGenTextures(1, &galbedo);
    glBindTexture(GL_TEXTURE_2D, galbedo);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
    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_ATTACHMENT2, GL_TEXTURE_2D, galbedo, 0);
    U32 attachments[3] = {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2};
    glDrawBuffers(3, attachments);

    U32 rbo; 
    glGenRenderbuffers(1, &rbo);
    glBindRenderbuffer(GL_RENDERBUFFER, rbo);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, width, height);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rbo);

    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
        fprintf(stderr, "error: gbuffer not complete\n");
    fprintf(stdout, "info: gbuffer complete\n");

    // shaders
    U32 shader_gbuffer = load_shader("gbuffer.vert", "gbuffer.frag");
    U32 shader_ssao = load_shader("ssao.vert", "ssao.frag");
    U32 shader_deferred = load_shader("deferred.vert", "deferred.frag");
    U32 shader_screen = load_shader("screen.vert", "screen.frag");
    U32 shader_occlusion = load_shader("screen.vert", "occlusion.frag");

    glUseProgram(shader_ssao);
    shader_set_1i(shader_ssao, "positions", 0);
    shader_set_1i(shader_ssao, "normals", 1);
    shader_set_1i(shader_ssao, "noise", 2);
    glUseProgram(shader_deferred);
    shader_set_1i(shader_deferred, "positions", 0);
    shader_set_1i(shader_deferred, "normals", 1);
    shader_set_1i(shader_deferred, "albedo", 2);
    shader_set_1i(shader_deferred, "ssao", 3);
    glUseProgram(0);

    S32 show_gbuffer = 0;

    S32 nsamples = 64;
    V3F *samples = malloc(nsamples * sizeof(V3F));
    S32 file = open("/dev/urandom", O_RDONLY);
    if (file < 0) {
        perror("error:");
        return 1;
    }
    U32 seed[4];
    if (read(file, seed, sizeof(seed)) < 0) {
        perror("error");
        return 1;
    }
    for (S32 i = 0; i < nsamples; i++) {
        V3F sample = {
            nextf(seed) * 2.0f - 1.0f,
            nextf(seed) * 2.0f - 1.0f,
            nextf(seed)
        };
        sample = v3f_norm(sample);
        float scale = (F32)i / 64.0f;
        scale = lerp(0.1f, 1.0f, scale * scale);
        sample = v3f_scalef(sample, scale);
        samples[i] = sample;
        assert(-1.0f < sample.x && sample.x < 1.0f);
        assert(-1.0f < sample.y && sample.y < 1.0f);
        assert(0.0f < sample.z && sample.z < 1.0f);
        // printf("color:\t%f\t%f\t%f\n", sample.x, sample.y, sample.z);
    }
    V3F noise[16];
    for (S32 i = 0; i < 16; i++) {
        noise[i] = (V3F){
            nextf(seed) * 2.0f - 1.0f,
            nextf(seed) * 2.0f - 1.0f,
            0.0f,
        };
    }
    close(file);

    U32 noise_texture;
    glGenTextures(1, &noise_texture);
    glBindTexture(GL_TEXTURE_2D, noise_texture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, 4, 4, 0, GL_RGB, GL_FLOAT, noise);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glBindTexture(GL_TEXTURE_2D, 0);

    U32 ssao_fbo;
    glGenFramebuffers(1, &ssao_fbo);
    glBindFramebuffer(GL_FRAMEBUFFER, ssao_fbo);
    U32 ssao_colorbuffer;
    glGenTextures(1, &ssao_colorbuffer);
    glBindTexture(GL_TEXTURE_2D, ssao_colorbuffer);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width, height, 0, GL_RED, GL_FLOAT, 0);
    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, ssao_colorbuffer, 0);
    glBindTexture(GL_TEXTURE_2D, 0);

    F64 last_time = glfwGetTime();
    while (!glfwWindowShouldClose(window)) {
        F64 time = glfwGetTime();
        F32 dt = time - last_time;
        last_time = time;

        input_update_last_state(&input);

        glfwPollEvents();
        glfwGetFramebufferSize(window, &width, &height);
        process_glfw_keyboard(window, &input);
        process_glfw_mouse_pos(window, &input);

        if (key_first_press(input.exit))
            glfwSetWindowShouldClose(window, GLFW_TRUE);

        F32 speed = 2.0f;
        V3F dv = get_dv_camera_first_person(&input, &camera, speed, dt);
        camera_dp = v3f_add(camera_dp, dv);
        camera_dp = v3f_scalef(camera_dp, 0.8f);
        camera.pos = v3f_add(camera.pos, camera_dp);

        F32 sensitivity = 0.1f;
        input.mouse_offset = v2f_scalef(input.mouse_offset, sensitivity);
        camera.yaw += input.mouse_offset.x;
        camera.pitch += input.mouse_offset.y;
        if (camera.pitch > 89.0f)
            camera.pitch = 89.0f;
        if (camera.pitch < -89.0f)
            camera.pitch = -89.0f;

        // update
        if (key_first_press(input.jump))
            show_gbuffer = !show_gbuffer;

        // render
        F32 ar = (F32)width / (F32)height;
        MAT4 projection = camera_persp(camera, ar);
        MAT4 view = get_view_matrix(&camera);

        glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        // render stuff into gbuffer
        glBindFramebuffer(GL_FRAMEBUFFER, gbuffer);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glUseProgram(shader_gbuffer);

        shader_set_mat4fv(shader_gbuffer, "projection", projection);
        shader_set_mat4fv(shader_gbuffer, "view", view);

        shader_set_mat4fv(shader_gbuffer, "model", mat4_identity());
        mesh_draw(cube);
        
        MAT4 model = mat4_make_scale(v3f(10.0f, 0.2f, 10.0f));
        model = mat4_translate(model, v3f(0.0f, -1.25f, 0.0f));
        shader_set_mat4fv(shader_gbuffer, "model", model);
        mesh_draw(cube);

        glUseProgram(0);

        glBindFramebuffer(GL_FRAMEBUFFER, 0);

        // render ssao texture
        glBindFramebuffer(GL_FRAMEBUFFER, ssao_fbo);
        glClear(GL_COLOR_BUFFER_BIT);

        glUseProgram(shader_ssao);

        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D, gpositions);

        glActiveTexture(GL_TEXTURE1);
        glBindTexture(GL_TEXTURE_2D, gnormals);

        glActiveTexture(GL_TEXTURE2);
        glBindTexture(GL_TEXTURE_2D, noise_texture);

        for (S32 i = 0; i < nsamples; i++) {

            char str[512] = {0};
            snprintf(str, 512, "samples[%d]", i);
            shader_set_3fv(shader_ssao, str, samples[i]);
        }
        shader_set_mat4fv(shader_ssao, "projection", projection);

        mesh_draw(quad);

        glUseProgram(0);

        glBindFramebuffer(GL_FRAMEBUFFER, 0);

        if (show_gbuffer) {
            MAT4 scale = mat4_make_scale(v3f(0.5f, 0.5f, 0.5f));
            MAT4 leftup = mat4_translate(scale, v3f(-0.5f, 0.5f, 0.0f));
            MAT4 rightup = mat4_translate(scale, v3f(0.5f, 0.5f, 0.0f));
            MAT4 leftdown = mat4_translate(scale, v3f(-0.5f, -0.5f, 0.0f));
            MAT4 rightdown = mat4_translate(scale, v3f(0.5f, -0.5f, 0.0f));

            glDisable(GL_DEPTH_TEST);

            glUseProgram(shader_screen);
            shader_set_mat4fv(shader_screen, "model", leftup);
            glActiveTexture(GL_TEXTURE0);
            glBindTexture(GL_TEXTURE_2D, gpositions);
            mesh_draw(quad);

            shader_set_mat4fv(shader_screen, "model", rightup);
            glBindTexture(GL_TEXTURE_2D, gnormals);
            mesh_draw(quad);

            shader_set_mat4fv(shader_screen, "model", leftdown);
            glBindTexture(GL_TEXTURE_2D, galbedo);
            mesh_draw(quad);
            glUseProgram(0);

            glUseProgram(shader_occlusion);
            shader_set_mat4fv(shader_occlusion, "model", rightdown);
            glBindTexture(GL_TEXTURE_2D, ssao_colorbuffer);
            mesh_draw(quad);
            glUseProgram(0);

            glEnable(GL_DEPTH_TEST);
        } else {
            // render scene lighting
            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

            glUseProgram(shader_deferred);

            glActiveTexture(GL_TEXTURE0);
            glBindTexture(GL_TEXTURE_2D, gpositions);

            glActiveTexture(GL_TEXTURE1);
            glBindTexture(GL_TEXTURE_2D, gnormals);
            
            glActiveTexture(GL_TEXTURE2);
            glBindTexture(GL_TEXTURE_2D, galbedo);

            glActiveTexture(GL_TEXTURE3);
            glBindTexture(GL_TEXTURE_2D, ssao_colorbuffer);

            V4F light_pos_v4 = v4f(light.position.x, light.position.y, light.position.z, 1.0f);
            V4F light_view_pos = mat4_v4f_mul(view, light_pos_v4);
            shader_set_3fv(shader_deferred, "light.position", v3f_from_v4f(light_view_pos));
            shader_set_3fv(shader_deferred, "light.color", light.color);
            shader_set_mat4fv(shader_deferred, "model", mat4_identity());

            mesh_draw(quad);

            glUseProgram(0);
        }

        glfwSwapBuffers(window);
    }

    return 0;
}