opengl 不会重叠超过 1 个纹理

Question

我正在尝试创建一个 opengl 程序来创建一个二维正方形，并在其上应用 2 个纹理。

我遵循了这个教程：https://learnopengl.com/Getting-started/Textures

这是我的片段着色器：

#version 330 core

//in vec3 Color;
in vec2 TexCoord;

out vec4 FragColor;

uniform sampler2D Texture1;
uniform sampler2D Texture2;

void main()
{
    FragColor = mix(texture(Texture1, TexCoord), texture(Texture2, TexCoord), 0.5);
}

这是发送纹理和制服的代码：

GLuint Tex1, Tex2;

int TexWidth, TexHeight, TexNrChannels;
unsigned char* TexData = stbi_load("container.jpg", &TexWidth, &TexHeight, &TexNrChannels, 0);
glGenTextures(1, &Tex1);
glBindTexture(GL_TEXTURE_2D, Tex1);
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);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, TexWidth, TexHeight, 0, GL_RGB, GL_UNSIGNED_BYTE, TexData);
glGenerateMipmap(GL_TEXTURE_2D);
glUniform1i(glGetUniformLocation(Program, "Texture1"), 0);
stbi_image_free(TexData);

TexData = stbi_load("awesomeface.png", &TexWidth, &TexHeight, &TexNrChannels, 0);
glGenTextures(1, &Tex2);
glBindTexture(GL_TEXTURE_2D, Tex2);
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);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TexWidth, TexHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, TexData);
glGenerateMipmap(GL_TEXTURE_2D);
glUniform1i(glGetUniformLocation(Program, "Texture2"), 1);
stbi_image_free(TexData);

这是渲染循环：

    while (!glfwWindowShouldClose(window))
{
    processInput(window);

    // GL render here
    glClearColor(0.05f, 0.0f, 0.1f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, Tex1);
    glActiveTexture(GL_TEXTURE1);
    glBindTexture(GL_TEXTURE_2D, Tex2);

    glUseProgram(Program);
    glBindVertexArray(VAO);
    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

    glfwSwapBuffers(window);
    glfwPollEvents();
}

当我运行它时，只有第一个纹理出现在正方形上，着色器中混合函数的 a 参数（最后一个参数）不会对任意值。

我尝试在渲染循环中首先激活（glActiveTexture + GlBindTexture）第二个纹理，它导致第二个纹理被独占显示。

如何像教程中那样将纹理混合在一起？

如果这个方法是错误的，我想学习另一种方法来实现同样的结果。

Answer 1

glUniform1i 在当前安装程序的默认统一块中设置一个值。您必须使用 glUseProgram 安装程序，然后才能设置统一变量的值：

GLint t1_loc = glGetUniformLocation(Program, "Texture1");
GLint t2_loc = glGetUniformLocation(Program, "Texture2");

glUseProgram(Program);
glUniform1i(t1_loc, 0);
glUniform1i(t2_loc, 1);

或者您可以使用 glProgramUniform1i:

glProgramUniform1i(Program, t1_loc, 0);
glProgramUniform1i(Program, t2_loc, 1);

opengl 不会重叠超过 1 个纹理

opengl won't overlap more than 1 texture

c++

windows

opengl