我正在开发一个图形项目，以使用 OpenGL 3.3 渲染纹理。使用 Perspective 投影时，代码将按预期方式渲染，但在 Orthoographic 投影中，不会渲染纹理。
我已经检查了由 glm :: ortho（）生成的4x4矩阵的值，并且所有值都是正确的。欢迎任何暗示可能发生的事情！
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <STBI/stb_image.h>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include "shader_m.h"
#include <iostream>
void framebuffer_size_callback( GLFWwindow* window, int width, int height );
void processInput( GLFWwindow *window );
const unsigned int SCR_WIDTH = 1920; // 1280; 800;
const unsigned int SCR_HEIGHT = 1080; // 720; 600;
int main()
{
glfwInit();
glfwWindowHint( GLFW_CONTEXT_VERSION_MAJOR, 3 );
glfwWindowHint( GLFW_CONTEXT_VERSION_MINOR, 3 );
glfwWindowHint( GLFW_OPENGL_PROFILE , GLFW_OPENGL_CORE_PROFILE );
GLFWwindow* window = glfwCreateWindow( SCR_WIDTH,
SCR_HEIGHT,
"LearnOpenGL",
NULL,
NULL );
if ( window == NULL )
{
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
glfwMakeContextCurrent( window );
glfwSetFramebufferSizeCallback( window, framebuffer_size_callback );
if ( !gladLoadGLLoader( (GLADloadproc)glfwGetProcAddress) )
{
std::cout << "Failed to initialize GLAD" << std::endl;
return -1;
}
glEnable( GL_DEPTH_TEST );
Shader ourShader( "Shaders/vertex.shader",
"Shaders/fragment.shader" );
float vertices[] =
{
100.0f, 100.0f, 0.0f, 1.0f, 1.0f,
200.0f, 100.0f, 0.0f, 1.0f, 0.0f,
200.0f, 200.0f, 0.0f, 0.0f, 0.0f,
100.0f, 200.0f, 0.0f, 0.0f, 1.0f
};
unsigned int indices[] =
{
0, 1, 3, // first triangle
1, 2, 3 // second triangle
};
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,
5 * sizeof( float ),
(void*)0 );
glEnableVertexAttribArray( 0 );
glVertexAttribPointer( 1,
2,
GL_FLOAT,
GL_FALSE,
5 * sizeof( float ),
(void*)( 3 * sizeof( float ) ) );
glEnableVertexAttribArray( 1 );
unsigned int texture1, texture2;
glGenTextures( 1,
&texture1 );
glBindTexture( GL_TEXTURE_2D,
texture1 );
glTexParameteri( GL_TEXTURE_2D,
GL_TEXTURE_WRAP_S,
GL_REPEAT );
glTexParameteri( GL_TEXTURE_2D,
GL_TEXTURE_WRAP_T,
GL_REPEAT );
glTexParameteri( GL_TEXTURE_2D,
GL_TEXTURE_MIN_FILTER,
GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D,
GL_TEXTURE_MAG_FILTER,
GL_LINEAR );
int width, height, nrChannels;
stbi_set_flip_vertically_on_load( true );
std::string filepath = "resources/container.jpg";
unsigned char *data = stbi_load( filepath.c_str(),
&width,
&height,
&nrChannels,
0 );
if ( data )
{
glTexImage2D( GL_TEXTURE_2D,
0,
GL_RGBA, //internal format
width,
height,
0,
GL_RGB, //
GL_UNSIGNED_BYTE,
data );
glGenerateMipmap( GL_TEXTURE_2D );
}
else
{
std::cout << "Failed to load texture" << std::endl;
}
stbi_image_free( data );
ourShader.use();
ourShader.setInt( "texture1",
0 );
while ( !glfwWindowShouldClose( window ) )
{
processInput( window );
glClearColor( 0.2f, 0.3f, 0.3f, 1.0f );
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glActiveTexture( GL_TEXTURE0 );
glBindTexture ( GL_TEXTURE_2D,
texture1 );
ourShader.use();
//create transformations
glm::mat4 model;
glm::mat4 view;
glm::mat4 projection;
//model = glm::rotate( model, glm::radians( -55.0f ), glm::vec3( 1.0f, 0.0f, 0.0f ) );
//model = glm::rotate( model, (float)glfwGetTime() * glm::radians( 50.0f ), glm::vec3( 0.5f, 1.0f, 0.0f ) );
view = glm::translate( view,
glm::vec3( 0.0f, 0.0f, -3.0f ) );
//-----------------------------------------------------------------------------------------
projection = glm::ortho( 0.0f,
960.0f,
0.0f,
540.0f,
-1.0f,
1.0f
);
//-----------------------------------------------------------------------------------------
/*
projection = glm::perspective( glm::radians( 45.0f ),
(float)SCR_WIDTH / (float)SCR_HEIGHT,
0.1f,
1000.0f );
*/
//-----------------------------------------------------------------------------------------
unsigned int modelLoc = glGetUniformLocation( ourShader.ID,
"model" );
unsigned int viewLoc = glGetUniformLocation( ourShader.ID,
"view" );
glUniformMatrix4fv( modelLoc,
1,
GL_FALSE,
glm::value_ptr( model ) );
glUniformMatrix4fv( viewLoc ,
1,
GL_FALSE,
&view[ 0 ][ 0 ] );
ourShader.setMat4( "projection",
projection );
glBindVertexArray( VAO );
glDrawElements( GL_TRIANGLES,
6,
GL_UNSIGNED_INT,
0 );
glfwSwapBuffers( window );
glfwPollEvents();
}
glDeleteVertexArrays( 1, &VAO );
glDeleteBuffers ( 1, &VBO );
glDeleteBuffers ( 1, &EBO );
glfwTerminate();
return 0;
}
以下是着色器：
#version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec2 aTexCoord;
out vec2 TexCoord;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
void main()
{
gl_Position = projection * view * model * vec4( aPos.x/1920.0f, aPos.y/1080.0f, 0.0f, 1.0 );
TexCoord = vec2( aTexCoord.x, aTexCoord.y );
}
#version 330 core
out vec4 FragColor;
in vec2 TexCoord;
uniform sampler2D texture1;
void main()
{
FragColor = texture( texture1, TexCoord );
}
答案 0 :(得分：1)
您必须初始化矩阵-另请参见Why is the sprite not rendering in OpenGL?：
glm::mat4 model(1.0f);
glm::mat4 view(1.0f);
glm::mat4 projection(1.0f);
由于设置了视图矩阵：
view = glm::translate(view, glm::vec3( 0.0f, 0.0f, -3.0f ) );
您必须增加到远端平面的距离：
例如10.0
projection = glm::ortho( 0.0f, 960.0f, 0.0f, 540.0f, -1.0f, 10.0f );
由于使用正交投影矩阵，因此无需缩放顶点着色器中的x和y坐标：
gl_Position = projection * view * model * vec4( aPos.x/1920.0f, aPos.y/1080.0f, 0.0f, 1.0 );
gl_Position = projection * view * model * vec4( aPos.xy, 0.0f, 1.0 );