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This code demonstrates the bug in framebuffers with the shadows.

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This commit is contained in:
Zed A. Shaw 2026-09-19 20:08:24 -04:00
parent 6235bfb657
commit 5577ab0f0b
7 changed files with 50 additions and 61 deletions
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8
33-shadow-mapping/config.json
View file

@ -59,10 +59,6 @@
"directory": "assets",
"model_path": "window.glb"
},
"human": {
"directory": "../assets",
"model_path": "human.glb"
},
"light_bulb": {
"directory": "assets",
"model_path": "light_bulb.glb"
@ -77,7 +73,7 @@
"rotation": {"angle": 0.0, "axes": [1.0, 1.0, 1.0]},
"scale": 1.0,
"material": "shiny"},
{"model": "human", "position": [1.28, 0.0, 1.33],
{"model": "marble_cube", "position": [1.28, 0.0, 1.33],
"rotation": {"angle": 0.0, "axes": [1.0, 1.0, 1.0]},
"scale": 1.0,
"material": "default"},
@ -85,7 +81,7 @@
"rotation": {"angle": 0.0, "axes": [1.0, 1.0, 1.0]},
"scale": 1.0,
"material": "shiny"},
{"model": "human", "position": [3.13, 0.80, 3.04],
{"model": "marble_cube", "position": [3.13, 0.80, 3.04],
"rotation": {"angle": 0.0, "axes": [1.0, 1.0, 1.0]},
"scale": 1.0,
"material": "shiny"},

66
33-shadow-mapping/src/framebuffer.cpp
View file

@ -3,70 +3,52 @@
#include <GLFW/glfw3.h>
void FrameBuffer::init() {
// target_fb configuration
// -------------------------
glGenFramebuffers(1, &target_fb);
glBindFramebuffer(GL_FRAMEBUFFER, target_fb);
glGenTextures(1, &texture_color_buffer);
// create the multisamples color attachment texture
glGenTextures(1, &texture_multi);
glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, texture_multi);
glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 4, GL_RGB, SCR_WIDTH, SCR_HEIGHT, GL_TRUE);
glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, texture_multi, 0);
// create a renderbuffer object for depth and stencil attachment (we won't be sampling these)
glGenRenderbuffers(1, &target_rbo);
glBindRenderbuffer(GL_RENDERBUFFER, target_rbo);
glRenderbufferStorageMultisample(GL_RENDERBUFFER, 4, GL_DEPTH24_STENCIL8, SCR_WIDTH, SCR_HEIGHT); // use a single renderbuffer object for both a depth AND stencil buffer.
glBindRenderbuffer(GL_RENDERBUFFER, 0);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, target_rbo); // now actually attach it
// now that we actually created the target_fb and added all attachments we want to check if it is actually complete now
dbc::check(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE, "Frame buffer not complete.");
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// intermediate fbo here
glGenFramebuffers(1, &intermediate_fbo);
glBindFramebuffer(GL_FRAMEBUFFER, intermediate_fbo);
// create a color attachment texture
glGenTextures(1, &texture_buffer);
glBindTexture(GL_TEXTURE_2D, texture_buffer);
glBindTexture(GL_TEXTURE_2D, texture_color_buffer);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, SCR_WIDTH, SCR_HEIGHT, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture_buffer, 0);
dbc::check(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE, "Frame buffer not complete.");
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture_color_buffer, 0);
glGenRenderbuffers(1, &target_rbo);
glBindRenderbuffer(GL_RENDERBUFFER, target_rbo);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, SCR_WIDTH, SCR_HEIGHT);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, target_rbo);
dbc::check(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE, "Failed to init framebuffer.");
glBindFramebuffer(GL_FRAMEBUFFER, 0);
invariant();
}
void FrameBuffer::begin() {
// target_fb stuff here
glBindFramebuffer(GL_FRAMEBUFFER, target_fb);
glEnable(GL_DEPTH_TEST);
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
}
void FrameBuffer::commit() {
// disable the frame buffer
glBindFramebuffer(GL_READ_FRAMEBUFFER, target_fb);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, intermediate_fbo);
glBlitFramebuffer(0, 0, SCR_WIDTH, SCR_HEIGHT, 0, 0, SCR_WIDTH, SCR_HEIGHT, GL_COLOR_BUFFER_BIT, GL_NEAREST);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glDisable(GL_DEPTH_TEST);
glClearColor(0.0f, 0.0f, 1.0, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
}
void FrameBuffer::draw(Screen& screen) {
glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
glDisable(GL_DEPTH_TEST);
screen.shader.use();
glBindVertexArray(screen.target_VAO);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture_buffer);
glActiveTexture(GL_TEXTURE0 + screen.texture_id);
glBindTexture(GL_TEXTURE_2D, texture_color_buffer);
glDrawArrays(GL_TRIANGLES, 0, 6);
}
void FrameBuffer::invariant() {
dbc::check(target_fb != UINT_MAX, "target_fb not initialized");
dbc::check(texture_color_buffer != UINT_MAX, "texture_color_buffer not initialized");
}

10
33-shadow-mapping/src/framebuffer.hpp
View file

@ -4,14 +4,14 @@
#include "screen.hpp"
struct FrameBuffer {
unsigned int target_fb = 0;
unsigned int intermediate_fbo = 0;
unsigned int target_rbo = 0;
unsigned int texture_buffer = 0;
unsigned int texture_multi = 0;
unsigned int target_fb = UINT_MAX;
unsigned int target_rbo = UINT_MAX;
unsigned int texture_color_buffer = UINT_MAX;
void init();
void begin();
void commit();
void draw(Screen& screen);
void invariant();
};

2
33-shadow-mapping/src/main.cpp
View file

@ -135,7 +135,7 @@ void update(GLFWwindow* window, std::shared_ptr<Scene> scene) {
void render(GLFWwindow* window, std::shared_ptr<Scene> scene, Text &text) {
scene->render(window);
text.render(text_content, 25.0f, 25.0f, 1.0f, glm::vec3(1.0, 0.0f, 0.0f));
// text.render(text_content, 25.0f, 25.0f, 1.0f, glm::vec3(1.0, 0.0f, 0.0f));
glfwSwapBuffers(window);
}

22
33-shadow-mapping/src/scene.cpp
View file

@ -53,6 +53,8 @@ void Scene::render_scene(GLFWwindow* window, Shader& with_shader) {
}
void Scene::render_shadows(GLFWwindow* window) {
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// temporarily use the config.json positioned even though this is doing a directional
auto& light_pos = light.positioned.at(0).position;
@ -80,11 +82,9 @@ void Scene::render_shadows(GLFWwindow* window) {
void Scene::render(GLFWwindow* window) {
auto& with_shader = reflect_on ? reflect_shader : shader;
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
render_shadows(window);
// set depth_map on TEXTURE0
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, depth_map);
@ -95,14 +95,23 @@ void Scene::render(GLFWwindow* window) {
with_shader.setVec3("lightPos", light.positioned.at(0).position);
with_shader.setMat4("lightSpaceMatrix", light_space);
framebuffer.begin();
render_scene(window, with_shader);
framebuffer.commit();
framebuffer.draw(screen);
if(debug_on) {
render_debug(window);
} else {
render_scene(window, with_shader);
}
}
void Scene::render_debug(GLFWwindow* window) {
// set depth_map on TEXTURE0
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, depth_map);
depth_dbg_shader.use();
depth_dbg_shader.setInt("shadowMap", 0);
depth_dbg_shader.setFloat("near_plane", depth_near_plane);
@ -134,7 +143,9 @@ void Scene::cleanup() {
void Scene::init_shadows() {
glGenFramebuffers(1, &depth_FBO);
glBindFramebuffer(GL_FRAMEBUFFER, depth_FBO);
glGenTextures(1, &depth_map);
glBindTexture(GL_TEXTURE_2D, depth_map);
glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, SHADOW_WIDTH, SHADOW_HEIGHT, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
@ -142,7 +153,6 @@ void Scene::init_shadows() {
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glBindFramebuffer(GL_FRAMEBUFFER, depth_FBO);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depth_map, 0);
glDrawBuffer(GL_NONE);
glReadBuffer(GL_NONE);

2
33-shadow-mapping/src/screen.cpp
View file

@ -4,7 +4,7 @@
void Screen::init() {
shader.use();
shader.setInt("screenTexture", 0);
shader.setInt("screenTexture", texture_id);
glGenVertexArrays(1, &target_VAO);
glGenBuffers(1, &target_VBO);

1
33-shadow-mapping/src/screen.hpp
View file

@ -5,6 +5,7 @@ struct Screen {
Shader shader;
unsigned int target_VAO = 0;
unsigned int target_VBO = 0;
unsigned int texture_id = 10;
float vertices[24] = {
// vertex attributes for a quad that fills the entire screen in Normalized Device Coordinates.