OpenGL 混合会在纹理周围创建白色边框

我正在尝试使用OpenGL(C++(将两个纹理渲染到一个矩形上。不过，我在将它们两者融合起来时遇到了一些麻烦。

第一个图像来自.jpg文件 (https://learnopengl.com/img/textures/container.jpg(。 此图像没有 Alpha 通道。

第二个图像来自.png文件 (https://learnopengl.com/img/textures/awesomeface.png(，并且确实具有 alpha 通道。

问题是当我尝试混合两个图像时，它会在透明图像周围创建一个白色边框。

我已经尝试了几种不同的混合模式(正如 OP 在这个问题中的建议：具有多种纹理的 Alpha 混合会留下彩色边框(，但它们似乎都不起作用。

我的片段着色器如下所示：

#version 330 core
out vec4 FragColor;
in vec3 ourColor;
in vec2 TexCoord;
// texture samplers
uniform sampler2D texture1;
uniform sampler2D texture2;
void main()
{
// linearly interpolate between both textures
FragColor = mix(texture(texture1, TexCoord), texture(texture2, TexCoord), 0.5);
}

我启用了深度测试(似乎没有任何效果(，并且我使用以下代码来设置混合：

glEnable(GL_DEPTH_TEST);
glEnable(GL_BLEND);
glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);

这是我的主要渲染循环：

Rendering::Pipeline pipeline = Rendering::Pipeline("src/GLSL/vertex.glsl", "src/GLSL/fragment.glsl");
pipeline.load();
//                     Position,               Color,                   Texture Coord.
//                     (X Y Z)                 (R G B)                  (S T)
float vertices [32] = { 0.5f,   0.5f,   0.0f,   1.0f,   0.0f,   0.0f,   1.0f, 1.0f, // top right
0.5f,   -0.5f,  0.0f,   0.0f,   1.0f,   0.0f,   1.0f, 0.0f, // bottom right
-0.5f,  -0.5f,  0.0f,   0.0f,   0.0f,   1.0f,   0.0f, 0.0f, // bottom left
-0.5f,  0.5f,   0.0f,   1.0f,   1.0f,   0.0f,   0.0f, 1.0f  };// top left
unsigned int vertexIndices [6] = {  3,  2,  0,
2,  1,  0   };

unsigned int vbo;
unsigned int vao;
unsigned int 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(vertexIndices), vertexIndices, 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 texture1;
unsigned int texture2;
int width;
int height;
int numChannels;
unsigned char* data;
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);
data = stbi_load("res/jpg/container.jpg", &width, &height, &numChannels, STBI_rgb);
if (data)
{
lTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
}
stbi_image_free(data);
glGenTextures(1, &texture2);
glBindTexture(GL_TEXTURE_2D, texture2);
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);
stbi_set_flip_vertically_on_load(true);
data = stbi_load("res/png/awesomeface.png", &width, &height, &numChannels, STBI_rgb_alpha);
if (data)
{
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
}
stbi_image_free(data);
glUseProgram(pipeline.getProgramId());
glUniform1i(glGetUniformLocation(pipeline.getProgramId(), "texture1"), 0);
glUniform1i(glGetUniformLocation(pipeline.getProgramId(), "texture2"), 1);
while (!this->mQuit)
{
this->counter.start();
InputProcessor::getInstance().processInputs();
if (this->debugOverlay)
{
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
}
else
{
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
}
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);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, texture2);
pipeline.use();
glBindVertexArray(vao);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
SDL_GL_SwapWindow(this->sdlWindow);
this->counter.stop();
this->deltaTime = this->counter.getDelta();
}
this->quit();

将 0.5 作为参数传递给片段着色器中的 mix(( 函数时，最容易观察到此问题。当使用 0.0 或 1.0 时，我(如预期的那样(只得到其中一个纹理。