我现在正在跃跃欲试的学习opengl，我遇到了一个问题。在我的台式电脑上，使用nvidia gtx 780，opengl通过glDebugMessageCallback机制打印出一个警告。
"缓冲对象1（绑定到_GL_ARRAY_BUFFER_ARB，使用提示是GL_STATIC_DRAW）将使用VIDEO内存作为缓冲对象操作的源头。"
我正在渲染1个带有顶点和索引缓冲区的立方体，所以这个消息在我创建的每一个缓冲对象（2个）中重复出现。然而，最后还有一条警告，其中写道："程序3中的顶点着色器在程序3中。
"程序3的顶点着色器正在根据GL状态重新编译"
我之前渲染的立方体还是可以渲染的，但是我设置的颜色现在却在白色和颜色之间闪烁。我在网上搜索了一下，找到了这个答案--。https:/community.khronos.orgtnvidia-output-debug-error-13118566033。 - 其中基本上说这只是一个警告，一切都应该是好的，但这不会解释为什么我的立方体现在在白色和我的颜色之间闪烁。这同样的代码在我的笔记本电脑上工作得很好（2019年华硕笔记本电脑，它也有一个nvidia GTX图形芯片）。之前有人遇到过这个问题吗？下面是相关代码。
const char* vertexShaderCode =
R"HereDoc(
#version 430
in layout(location=0) vec3 position;
in layout(location=1) vec3 color;
out vec3 fragColor;
uniform mat4 transformationMatrix;
void main()
{
vec4 newPos = vec4(position, 1.0) * transformationMatrix;//vector is on the left side because my matrices are row major
gl_Position = newPos;
vec3 changedColors;
changedColors.r += color.r + 0;
changedColors.g += color.g + 0;
changedColors.b += color.b + 0;
fragColor = changedColors;
};
)HereDoc";
const char* fragmentShaderCode =
R"HereDoc(
#version 430
out vec4 color;
in vec3 fragColor;
void main()
{
color = vec4(fragColor, 1.0f);
};
)HereDoc";
void GLAPIENTRY MyOpenGLErrorCallbackFunc(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar *message, const void *userParam)
{
BGZ_CONSOLE("%s type=0x%x %s\n", ( type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : "" ), type, message);
};
void CheckCompileStatus(GLuint shaderID)
{
GLint compileStatus;
glGetShaderiv(shaderID, GL_COMPILE_STATUS, &compileStatus);
if(compileStatus != GL_TRUE)
{
GLint infoLogLength;
glGetShaderiv(shaderID, GL_INFO_LOG_LENGTH, &infoLogLength);
GLchar buffer[512] = {};
GLsizei bufferSize;
glGetShaderInfoLog(shaderID, infoLogLength, &bufferSize, buffer);
BGZ_CONSOLE("%s", buffer);
InvalidCodePath;
};
};
void CheckLinkStatus(GLuint programID)
{
GLint linkStatus;
glGetProgramiv(programID, GL_LINK_STATUS, &linkStatus);
if(linkStatus != GL_TRUE)
{
GLint infoLogLength;
glGetProgramiv(programID, GL_INFO_LOG_LENGTH, &infoLogLength);
GLchar buffer[512] = {};
GLsizei bufferSize;
glGetProgramInfoLog(programID, infoLogLength, &bufferSize, buffer);
BGZ_CONSOLE("%s", buffer);
InvalidCodePath;
};
};
local_func void InstallShaders()
{
GLuint vertexShaderID = glCreateShader(GL_VERTEX_SHADER);
GLuint fragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER);
const char* adapter[1];
adapter[0] = vertexShaderCode;
glShaderSource(vertexShaderID, 1, adapter, 0);
adapter[0] = fragmentShaderCode;
glShaderSource(fragmentShaderID, 1, adapter, 0);
glCompileShader(vertexShaderID);
glCompileShader(fragmentShaderID);
CheckCompileStatus(vertexShaderID);
CheckCompileStatus(fragmentShaderID);
GLuint programID = glCreateProgram();
glAttachShader(programID, vertexShaderID);
glAttachShader(programID, fragmentShaderID);
glLinkProgram(programID);
CheckLinkStatus(programID);
glUseProgram(programID);
};
local_func void
GLInit(int windowWidth, int windowHeight)
{
glEnable(GL_DEBUG_OUTPUT);
glDebugMessageCallback(MyOpenGLErrorCallbackFunc, 0);
glViewport(0, 0, windowWidth, windowHeight);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);//Defaults to CCW ordering of indicies meaning all indicies that, from the viewers perspective, creating triangles in a CW manner repsrent visible triangles.
glCullFace(GL_BACK);//Culls only back faces (faces facing away from viewer)
InstallShaders();
}
void Draw(Memory_Partition* memPart, s32 id, RunTimeArr<s16> meshIndicies)
{
glDisable(GL_TEXTURE_2D);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 2);
glDrawElements(GL_TRIANGLES, (s32)meshIndicies.length, GL_UNSIGNED_SHORT, 0);
glEnable(GL_TEXTURE_2D);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
};
//This implements a discriminated union for buffering render commands that my game code layer uses.
void RenderViaHardware(Rendering_Info&& renderingInfo, Memory_Partition* platformMemoryPart, int windowWidth, int windowHeight)
{
local_persist bool glIsInitialized { false };
if (NOT glIsInitialized)
{
GLInit(windowWidth, windowHeight);
glClearColor(0.0f, 0.0f, 1.0f, 0.0f);
glIsInitialized = true;
};
u8* currentRenderBufferEntry = renderingInfo.cmdBuffer.baseAddress;
Camera3D camera3d = renderingInfo.camera3d;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_TEXTURE_2D);
for (s32 entryNumber = 0; entryNumber < renderingInfo.cmdBuffer.entryCount; ++entryNumber)
{
RenderEntry_Header* entryHeader = (RenderEntry_Header*)currentRenderBufferEntry;
switch (entryHeader->type)
{
case EntryType_InitBuffer:{
RenderEntry_InitBuffer bufferData = *(RenderEntry_InitBuffer*)currentRenderBufferEntry;
ScopedMemory scope{platformMemoryPart};
RunTimeArr<GLfloat> verts{};
InitArr(verts, platformMemoryPart, bufferData.verts.length * 6);
s32 i{};
f32 colorR{1.0f}, colorG{}, colorB{};//Im just hard coding color data right now while I'm learning
for(s32 j{}; j < bufferData.verts.length; ++j)
{
verts.Push(bufferData.verts[j].x);
verts.Push(bufferData.verts[j].y);
verts.Push(bufferData.verts[j].z);
verts.Push(colorR);
verts.Push(colorG);
verts.Push(colorB);
};
u32 vertexArrayID{};
glGenVertexArrays(1, &vertexArrayID);
glBindVertexArray(vertexArrayID);
GLuint bufferID;
glGenBuffers(1, &bufferID);
glBindBuffer(GL_ARRAY_BUFFER, bufferID);
glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * verts.length, verts.elements, GL_DYNAMIC_DRAW);
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 6, 0);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(GLfloat) * 6, (char*)(sizeof(GLfloat)*3));
GLuint indexBufferID;
glGenBuffers(1, &indexBufferID);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBufferID);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(s16) * bufferData.indicies.length, bufferData.indicies.elements, GL_DYNAMIC_DRAW);
currentRenderBufferEntry += sizeof(RenderEntry_InitBuffer);
}break;
//...other cases for entries which are irrelevant to problem
case EntryType_Geometry: {
ScopedMemory scope{platformMemoryPart};
RenderEntry_Geometry geometryEntry = *(RenderEntry_Geometry*)currentRenderBufferEntry;
//camera transform setup
Mat4x4 xRotMatrix = XRotation(camera3d.rotation.x);
Mat4x4 yRotMatrix = YRotation(camera3d.rotation.y);
Mat4x4 zRotMatrix = ZRotation(camera3d.rotation.z);
Mat4x4 fullRotMatrix = xRotMatrix * yRotMatrix * zRotMatrix;
v3 xAxis = GetColumn(fullRotMatrix, 0);
v3 yAxis = GetColumn(fullRotMatrix, 1);
v3 zAxis = GetColumn(fullRotMatrix, 2);
//Setup full transform matrix
Mat4x4 camTransform = ProduceCameraTransformMatrix(xAxis, yAxis, zAxis, camera3d.worldPos);
Mat4x4 projectionTransform = ProduceProjectionTransformMatrix_UsingFOV(renderingInfo.fov, renderingInfo.aspectRatio, renderingInfo.nearPlane, renderingInfo.farPlane);
Mat4x4 fullTransformMatrix = projectionTransform * camTransform * geometryEntry.worldTransform;
//Send transform matrix to vertex shader
GLint transformMatrixUniformLocation = glGetUniformLocation(3, "transformationMatrix");
glUniformMatrix4fv(transformMatrixUniformLocation, 1, GL_FALSE, &fullTransformMatrix.elem[0][0]);
Draw(platformMemoryPart, geometryEntry.id, geometryEntry.indicies);
currentRenderBufferEntry += sizeof(RenderEntry_Geometry);
}break;
InvalidDefaultCase;
};
}
renderingInfo.cmdBuffer.entryCount = 0;
};
EDIT:
我想明白了颜色不工作的问题，这在下面的评论中得到了回答。然而，我仍然不知道这些警告试图告诉我什么，如果他们是什么，我应该寻找修复。
你的变量 vec3 changedColors; 是未初始化的。将其初始化为 vec3 changedColors = vec3(0);. 之所以在你的笔记本上能用，可能是它的显卡驱动会默认将其初始化为零，而你的其他显卡驱动不会。
关于警告（不是错误）。它只是警告你，你的缓冲区将被放在视频内存中，因为你使用的是 GL_STATIC_DRAW 的缓冲区。它实际上更像是一个日志，你可以安全地忽略它。如果你想删除它，你必须在你的回调中把它过滤掉（你把它传递给了 glDebugMessageCallback). 您的回调将有一个 severity 参数，让你过滤具有一定严重性的信息。
或者，如果你只想删除那个特定的信息，可以用它的 id 值。
下面是一个例子，取自 blog.nobel-joergensen.com:
void APIENTRY openglCallbackFunction(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar* message, const void* userParam)
{
cout << "---------------------opengl-callback-start------------" << endl;
cout << "message: "<< message << endl;
cout << "type: ";
switch (type) {
case GL_DEBUG_TYPE_ERROR:
cout << "ERROR";
break;
case GL_DEBUG_TYPE_DEPRECATED_BEHAVIOR:
cout << "DEPRECATED_BEHAVIOR";
break;
case GL_DEBUG_TYPE_UNDEFINED_BEHAVIOR:
cout << "UNDEFINED_BEHAVIOR";
break;
case GL_DEBUG_TYPE_PORTABILITY:
cout << "PORTABILITY";
break;
case GL_DEBUG_TYPE_PERFORMANCE:
cout << "PERFORMANCE";
break;
case GL_DEBUG_TYPE_OTHER:
cout << "OTHER";
break;
}
cout << endl;
cout << "id: " << id << endl;
cout << "severity: ";
switch (severity){
case GL_DEBUG_SEVERITY_LOW:
cout << "LOW";
break;
case GL_DEBUG_SEVERITY_MEDIUM:
cout << "MEDIUM";
break;
case GL_DEBUG_SEVERITY_HIGH:
cout << "HIGH";
break;
}
cout << endl;
cout << "---------------------opengl-callback-end--------------" << endl;
}