GLFW GLAD 未绘制纹理,黑色方块
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【中文标题】GLFW GLAD 未绘制纹理,黑色方块【英文标题】:GLFW GLAD Texture not drawn, black square 【发布时间】:2019-03-22 17:13:14 【问题描述】:我正在尝试为由两个三角形组成的正方形绘制纹理。但是,它显示的不是带有纹理的正方形,而是黑色正方形。此外,shader.h 与颜色完美搭配。这不是 main.cpp 中的所有代码,只是纹理代码。
Main.cpp
Shader defShader("resources/shaders/vertex.txt", "resources/shaders/fragment.txt");
float vertices[] =
0.5f, 0.5f, 0.0f, 1.0f,0.0f,0.0f, 1.0f,1.0f,
0.5f, -0.5f, 0.0f, 0.0f,1.0f,0.0f, 1.0f,0.0f,
-0.5f,-0.5f, 0.0f, 1.0f,1.0f,0.0f, 0.0f,1.0f,
-0.5f, 0.5f, 0.0f, 1.0f,1.0f,0.0f, 0.0f,1.0f
;
unsigned int indices[] =
0,1,3,
1,2,3
;
unsigned int VBO, VAO, EBO;
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
glGenBuffers(1, &EBO);
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
glEnableVertexAttribArray(1);
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
glEnableVertexAttribArray(2);
unsigned int texture;
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
// Set texture wrap parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
// Set texture filtering paremeters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// Load image, create texture and generate mipmaps
int w, h, nrChannels;
unsigned char *data = stbi_load("resources/textures/wall.jpg", &w, &h, &nrChannels, 0);
if (data)
std::cout << "LOADING TEXTURE\n" << std::endl;
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, w, h, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, 0);
else
std::cout << "FAILED TO LOAD TEXTURE\n" << std::endl;
stbi_image_free(data);
while (!glfwWindowShouldClose(window))
processInput(window);
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
// Render stuff
defShader.Use();
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
glBindVertexArray(0);
glfwSwapBuffers(window);
glfwPollEvents();
glfwTerminate();
return 0;
这里是着色器。 vertShader.txt
#version 330 core
layout(location = 0) in vec3 aPos;
layout(location = 1) in vec3 aColor;
layout(location = 2) in vec2 aTexCoord;
out vec3 ourColor;
out vec2 TexCoord;
void main()
gl_Position = vec4(aPos, 1.0);
ourColor = aColor;
TexCoord = aTexCoord;
fragShader.txt
#version 330 core
out vec4 FragColor;
in vec3 ourColor;
in vec2 TexCoord;
uniform sampler2D ourTexture;
void main()
FragColor = texture(ourTexture, TexCoord);
【问题讨论】:
Related: ***.com/questions/4041124/… 如果没有,您应该尝试使用renderdoc等工具进行捕获 为什么在绘制之前不重新绑定纹理对象? @genpfault 我该怎么做? @Borgleader 如何使用 renderdoc? 与上传纹理图像的方式相同:glBindTexture(GL_TEXTURE_2D, texture)
.
【参考方案1】:
几个问题:
将stbi_load()
的desired_channels
设置为3
,而不是仅仅希望图像是3 通道。
设置glPixelStorei(GL_UNPACK_ALIGNMENT, 1)
,以防加载的图片与默认的4
不匹配。
您在加载纹理对象后立即解除绑定;请务必在绘制之前重新绑定它。
使用 stbi_set_flip_vertically_on_load(1)
(或修改您的 texcoords)为 OpenGL 以“正确”方式翻转图像。
您的顶点/texcoords/indexes 有点不稳定;我把它们修好了,让我觉得有意义。
你真的应该设置你的着色器应该从哪个特定的纹理单元进行采样,而不是依赖于未分配的采样器制服默认为零的事实:
unsigned int texture_unit = 0;
glActiveTexture( GL_TEXTURE0 + texture_unit );
glUniform1i( glGetUniformLocation( prog, "ourTexture" ), texture_unit );
大家一起:
#include <glad/glad.h>
#define GLFW_INCLUDE_NONE
#include <GLFW/glfw3.h>
#include <iostream>
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
void CheckStatus( GLuint obj, bool isShader )
GLint status = GL_FALSE, log[ 1 << 11 ] = 0 ;
( isShader ? glGetShaderiv : glGetProgramiv )( obj, isShader ? GL_COMPILE_STATUS : GL_LINK_STATUS, &status );
if( status == GL_TRUE ) return;
( isShader ? glGetShaderInfoLog : glGetProgramInfoLog )( obj, sizeof( log ), NULL, (GLchar*)log );
std::cerr << (GLchar*)log << "\n";
std::exit( EXIT_FAILURE );
void AttachShader( GLuint program, GLenum type, const char* src )
GLuint shader = glCreateShader( type );
glShaderSource( shader, 1, &src, NULL );
glCompileShader( shader );
CheckStatus( shader, true );
glAttachShader( program, shader );
glDeleteShader( shader );
const char* vert = 1 + R"GLSL(
#version 330 core
layout(location = 0) in vec3 aPos;
layout(location = 1) in vec3 aColor;
layout(location = 2) in vec2 aTexCoord;
out vec3 ourColor;
out vec2 TexCoord;
void main()
gl_Position = vec4(aPos, 1.0);
ourColor = aColor;
TexCoord = aTexCoord;
)GLSL";
const char* frag = 1 + R"GLSL(
#version 330 core
out vec4 FragColor;
in vec3 ourColor;
in vec2 TexCoord;
uniform sampler2D ourTexture;
void main()
FragColor = texture(ourTexture, TexCoord);
)GLSL";
int main( int, char** )
glfwSetErrorCallback( []( int, const char* desc ) std::cerr << desc << "\n"; std::exit( EXIT_FAILURE ); );
glfwInit();
glfwWindowHint( GLFW_CONTEXT_VERSION_MAJOR, 3 );
glfwWindowHint( GLFW_CONTEXT_VERSION_MINOR, 3 );
glfwWindowHint( GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE );
glfwWindowHint( GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE );
GLFWwindow* window = glfwCreateWindow( 640, 480, "GLFW", NULL, NULL );
glfwMakeContextCurrent( window );
gladLoadGLLoader( (GLADloadproc)glfwGetProcAddress );
GLuint prog = glCreateProgram();
AttachShader( prog, GL_VERTEX_SHADER, vert );
AttachShader( prog, GL_FRAGMENT_SHADER, frag );
glLinkProgram( prog );
CheckStatus( prog, false );
float vertices[] =
-0.5f, -0.5f, 0.0f, 1.0f,1.0f,0.0f, 0.0f,0.0f,
0.5f, -0.5f, 0.0f, 0.0f,1.0f,0.0f, 1.0f,0.0f,
0.5f, 0.5f, 0.0f, 1.0f,0.0f,0.0f, 1.0f,1.0f,
-0.5f, 0.5f, 0.0f, 1.0f,1.0f,0.0f, 0.0f,1.0f
;
unsigned int indices[] =
0,1,2,
2,3,0
;
unsigned int VBO, VAO, EBO;
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
glGenBuffers(1, &EBO);
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
glEnableVertexAttribArray(1);
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
glEnableVertexAttribArray(2);
unsigned int texture;
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
// Set texture wrap parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
// Set texture filtering paremeters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// Load image, create texture and generate mipmaps
int w, h;
stbi_set_flip_vertically_on_load( 1 );
// https://upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Brick_wall_close-up_view.jpg/800px-Brick_wall_close-up_view.jpg
unsigned char *data = stbi_load("wall.jpg", &w, &h, NULL, 3);
if (data)
std::cout << "LOADING TEXTURE: " << w << "x" << h << std::endl;
glPixelStorei( GL_UNPACK_ALIGNMENT, 1 );
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, w, h, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, 0);
else
std::cout << "FAILED TO LOAD TEXTURE\n" << std::endl;
stbi_image_free(data);
while (!glfwWindowShouldClose(window))
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
// Render stuff
glUseProgram( prog );
unsigned int texture_unit = 0;
glActiveTexture( GL_TEXTURE0 + texture_unit );
glUniform1i( glGetUniformLocation( prog, "ourTexture" ), texture_unit );
glBindTexture(GL_TEXTURE_2D, texture);
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
glBindVertexArray(0);
glfwSwapBuffers(window);
glfwPollEvents();
【讨论】:
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