有这个代码:
#include <iostream>
#include <vector>
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#define STB_IMAGE_IMPLEMENTATION
#include <stb/stb_image.h>
#include <test/main/shader.hpp>
// size of the images has to be the same
// https://stackoverflow.com/questions/75976623/how-to-use-gl-texture-2d-array-for-binding-multiple-textures-as-array/75976728?noredirect=1#comment134006728_75976728
uint32_t BuildTextureArray(const std::vector<std::string>& paths) {
int width, height;
stbi_set_flip_vertically_on_load(1);
uint8_t *data_of_first = stbi_load(paths[0].c_str(), &width, &height, nullptr, 4);
uint32_t array_id;
glGenTextures(1, &array_id);
glBindTexture(GL_TEXTURE_2D_ARRAY, array_id);
glTexImage3D(GL_TEXTURE_2D_ARRAY, 0, GL_RGBA, width, height, paths.size(), 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexSubImage3D(GL_TEXTURE_2D_ARRAY, 0, 0, 0, 0, width, height, 1, GL_RGBA, GL_UNSIGNED_BYTE, data_of_first);
for (int i = 1; i < paths.size(); i++) {
uint8_t *data = stbi_load(paths[i].c_str(), nullptr, nullptr, nullptr, 4);
glTexSubImage3D(GL_TEXTURE_2D_ARRAY, 0, 0, 0, i, width, height, 1, GL_RGBA, GL_UNSIGNED_BYTE, data);
}
return array_id;
}
int main() {
glfwInit();
GLFWwindow *window = glfwCreateWindow(960, 540, "test", nullptr, nullptr);
if (window == nullptr) {
std::cerr << "failed to create GLFW window\n";
}
glfwMakeContextCurrent(window);
glfwSetFramebufferSizeCallback(window, [](GLFWwindow *_, int width, int height) {
glViewport(0, 0, width, height);
});
if (!gladLoadGLLoader((GLADloadproc) glfwGetProcAddress)) {
std::cerr << "failed to initialize GLAD\n";
}
glEnable(GL_DEPTH_TEST);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
Shader shader("assets/GLSL/test.glsl");
shader.Bind();
uint32_t texture_array = BuildTextureArray({"assets/textures/logo.png", "assets/textures/homer.png"});
glBindTexture(GL_TEXTURE_2D_ARRAY, texture_array);
shader.SetInt("u_textures", 0);
uint32_t quad_va, quad_vb, quad_ib;
glGenVertexArrays(1, &quad_va);
glBindVertexArray(quad_va);
float vertices[] = {
// first texture - logo.png
-1.5f, -0.5f, 0.0f, 0.0f, 0.0f, 0.0f,
-0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f,
-0.5f, 0.5f, 0.0f, 1.0f, 1.0f, 0.0f,
-1.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f,
// second texture - homer.png
0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f,
1.5f, -0.5f, 0.0f, 1.0f, 0.0f, 1.0f,
1.5f, 0.5f, 0.0f, 1.0f, 1.0f, 1.0f,
0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f
};
glGenBuffers(1, &quad_vb);
glBindBuffer(GL_ARRAY_BUFFER, quad_vb);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(float) * 6, nullptr);
glEnableVertexAttribArray(0);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 6,
reinterpret_cast<const void *>(sizeof(float) * 3));
glEnableVertexAttribArray(1);
glVertexAttribPointer(2, 1, GL_FLOAT, GL_FALSE, sizeof(float) * 6,
reinterpret_cast<const void *>(sizeof(float) * 5));
glEnableVertexAttribArray(2);
uint32_t indices[] = {
0, 1, 2, 2, 3, 0,
4, 5, 6, 6, 7, 4
};
glGenBuffers(1, &quad_ib);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, quad_ib);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
while (!glfwWindowShouldClose(window)) {
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
shader.Bind();
glBindVertexArray(quad_va);
glDrawElements(GL_TRIANGLES, 12, GL_UNSIGNED_INT, nullptr);
glfwSwapBuffers(window);
glfwPollEvents();
}
}
着色器:
#type vertex
#version 450 core
layout(location = 0) in vec3 a_pos;
layout(location = 1) in vec2 a_texcoord;
layout(location = 0) in float a_texindex;
out vec2 v_texcoord;
out float v_texindex;
void main()
{
v_texcoord = a_texcoord;
v_texindex = a_texindex;
gl_Position = vec4(a_pos, 1.0);
}
#type fragment
#version 450 core
in vec2 v_texcoord;
in float v_texindex;
uniform sampler2DArray u_textures;
out vec4 color;
void main()
{
color = texture(u_textures, vec3(v_texcoord.xy, v_texindex));
}
其中Shader类(未显示)仅使用顶点和片段部分解析着色器文件。现在两个纹理通过最后一个属性指针进行区分,第一个纹理为浮点0.0f,第二个纹理为1.0f。运行此操作将导致segfault。segfault由BuildTextureArray()
函数引起(它可以在没有它的情况下运行,但当然不会有数组纹理)。我已经尝试根据How to use GL_TEXTURE_2D_ARRAY in OpenGL 3.2创建该函数,所以不应该重复,因为我正在使用那里的代码。而且因为我手头没有调试器,我不能通过这个函数。但是因为它是刚刚复制的,什么地方出错了?图像logo.png
和homer.png
的大小相同1024x1024
PS:为了完整性,这里是着色器类:
- header*:
#ifndef TEST_SHADER_HPP
#define TEST_SHADER_HPP
#include <string>
#include <glm/glm.hpp>
class Shader {
public:
explicit Shader(const std::string& filepath);
void Bind() const;
void SetInt(const std::string& name, int value) const;
void SetIntArray(const std::string& name, int *values, int count);
void SetFloat(const std::string& name, float value) const;
void SetVec3(const std::string& name, const glm::vec3& vec) const;
void SetVec4(const std::string& name, const glm::vec4& vec) const;
void SetMat4(const std::string& name, const glm::mat4& mat) const;
private:
static void CheckCompileErrors(uint32_t shader_id, const std::string& type, const std::string& filepath);
uint32_t id_;
};
#endif //TEST_SHADER_HP
- 来源 *:
#include <test/main/shader.hpp>
#include <iostream>
#include <fstream>
#include <sstream>
#include <glad/glad.h>
void Shader::CheckCompileErrors(uint32_t shader_id, const std::string& type, const std::string& filepath) {
int success;
char infoLog[1024];
if (type != "PROGRAM") {
glGetShaderiv(shader_id, GL_COMPILE_STATUS, &success);
if (!success) {
glGetShaderInfoLog(shader_id, 1024, nullptr, infoLog);
std::cout << "ERROR::SHADER::COMPILATION_ERROR of type: " << type << "\n" << infoLog << "filepath: "
<< filepath;
}
} else {
glGetProgramiv(shader_id, GL_LINK_STATUS, &success);
if (!success) {
glGetProgramInfoLog(shader_id, 1024, nullptr, infoLog);
std::cout << "ERROR::PROGRAM_LINKING_ERROR of type: " << type << "\n" << infoLog << "filepath: "
<< filepath;
}
}
}
Shader::Shader(const std::string& filepath) {
// 1. divide vertex and fragment part
enum class ShaderType {
NONE = -1, VERTEX = 0, FRAGMENT = 1
};
std::ifstream stream(filepath);
std::string line;
std::stringstream ss[2];
ShaderType type = ShaderType::NONE;
while (getline(stream, line)) {
if (line.find("#type") != std::string::npos) {
if (line.find("vertex") != std::string::npos) {
type = ShaderType::VERTEX;
} else if (line.find("fragment") != std::string::npos) {
type = ShaderType::FRAGMENT;
} else {
std::cout << "Unknown shader: " << line << '\n';
}
} else {
if (type == ShaderType::NONE) {
std::cout << "No shader defined" << '\n';
} else {
ss[(int) type] << line << '\n';
}
}
}
std::string vertex_code = ss[(int) ShaderType::VERTEX].str();
std::string fragment_code = ss[(int) ShaderType::FRAGMENT].str();
// 2. convert, compile and link sources to shader program
// 2.1 convert string to c str
const char *vertex_str = vertex_code.c_str();
const char *fragment_str = fragment_code.c_str();
// 2.2.1 vertex shader
uint32_t vertex_id = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertex_id, 1, &vertex_str, nullptr);
glCompileShader(vertex_id);
CheckCompileErrors(vertex_id, "VERTEX", filepath);
// 2.2.2 fragment shader
uint32_t fragment_id = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragment_id, 1, &fragment_str, nullptr);
glCompileShader(fragment_id);
CheckCompileErrors(fragment_id, "FRAGMENT", filepath);
// 2.3 shader program
id_ = glCreateProgram();
glAttachShader(id_, vertex_id);
glAttachShader(id_, fragment_id);
glLinkProgram(id_);
CheckCompileErrors(id_, "PROGRAM", filepath);
// 2.4 delete the shaders as they're linked into program and no longer necessary
glDeleteShader(vertex_id);
glDeleteShader(fragment_id);
}
void Shader::Bind() const {
glUseProgram(id_);
}
void Shader::SetInt(const std::string& name, int value) const {
glUniform1i(glGetUniformLocation(id_, name.c_str()), value);
}
void Shader::SetIntArray(const std::string& name, int *values, int count) {
glUniform1iv(glGetUniformLocation(id_, name.c_str()), count, values);
}
void Shader::SetFloat(const std::string& name, float value) const {
glUniform1f(glGetUniformLocation(id_, name.c_str()), value);
}
void Shader::SetVec4(const std::string& name, const glm::vec4& vec) const {
glUniform4f(glGetUniformLocation(id_, name.c_str()), vec.x, vec.y, vec.z, vec.w);
}
void Shader::SetVec3(const std::string& name, const glm::vec3& vec) const {
glUniform3f(glGetUniformLocation(id_, name.c_str()), vec.x, vec.y, vec.z);
}
void Shader::SetMat4(const std::string& name, const glm::mat4& mat) const {
glUniformMatrix4fv(glGetUniformLocation(id_, name.c_str()), 1, GL_FALSE, &mat[0][0]);
}
2条答案
按热度按时间mwkjh3gx1#
很有可能你的纹理根本找不到,或者两个图像的大小不一样。在glTexSubImage中使用图像加载器之前,你并没有真正检查它的返回值,也没有验证图像的大小是否相同。
测试返回值应该总是做的,特别是与文件IO,因为它总是会失败在某些时候...同样的假设图像大小...宽/高的新图像应检查-它是相同的大小作为第一个图像。
因为我手头没有调试器,所以我不能遍历该函数。
如果没有某种方法来查看代码在实际中的作用,你就不能期望编写代码时有效率。
rekjcdws2#
segfault问题发生在第二次调用
stbi_load()
(for循环内部)时,我使用nullptr
作为width,height和channels指针。我不知道为什么,但必须指定width和hight指针。我为此放置了dummy stack int,它工作了。但是由于
stbi_load()
来自第三方,我不能控制它的实现,所以我对此无能为力。