我目前正在使用 C++ 开发 2D 引擎。
我遇到了一个问题,我似乎相信我以前遇到过一次,但后来忘记了我是如何解决它的。
该引擎是跨平台的(Win、OSX、Linux),为此我使用 GLFW 作为基础。
当做正常的纹理处理时,我最终得到了这个:
如您所见,纹理不正确(因为图像应该是我的简单图像)。
使用 geDebugger,我可以确认缓冲到 GPU 的图像是正确的,但是正如您在图像中看到的那样,它是如何结束的。
我将在下面包含一些相关代码的削减,但如果您想了解更多信息,请随时询问。
-缓冲区生成代码
glGenVertexArrays( 1, &_vao );
// Generate Buffers and so on.
glBindVertexArray( _vao );
glGenBuffers( 1, &_vboVertices );
glBindBuffer( GL_ARRAY_BUFFER, _vboVertices );
glBufferData( GL_ARRAY_BUFFER, sizeof(GLfloat) * 3 * _numVertices, _vertices, GL_STATIC_DRAW );
glGenBuffers( 1, &_vboTexCoords );
glBindBuffer( GL_ARRAY_BUFFER, _vboTexCoords );
glBufferData( GL_ARRAY_BUFFER, sizeof(GLfloat) * 2 * _numVertices, _texCoords, GL_STATIC_DRAW );
glGenBuffers( 1, &_vboIndices );
glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, _vboIndices );
glBufferData( GL_ELEMENT_ARRAY_BUFFER, sizeof(GLint) * _numIndices, _indices, GL_STATIC_DRAW );
- 渲染代码
glm::mat4 modelViewProjMatrix = projMatrix * viewMatrix * modelMatrix;
ShaderResource * shader = ShaderManager::GetInstance()->GetShader( _shaderName.c_str() );
TextureResource * texture = TextureManager::GetInstance()->GetTexture( _textureName.c_str() );
shader->BindShader();
// Bind VAO
glBindVertexArray( _vao );
// Bind all VBO's
glBindBuffer( GL_ARRAY_BUFFER, _vboVertices );
GLint posLocation = shader->GetAttribLocation("in_position");
glVertexAttribPointer( posLocation, 3, GL_FLOAT, GL_FALSE, 0, (void*)0 );
GLint texCoordLocation = shader->GetAttribLocation("in_texCoord");
glVertexAttribPointer( texCoordLocation, 2, GL_FLOAT, GL_FALSE, 0, (void*)0 );
glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, _vboIndices );
// Enable VBO Pointers
glEnableVertexAttribArray( posLocation );
glEnableVertexAttribArray( texCoordLocation );
// Find and assign Uniforms
GLint MVPMatrixLocation = shader->GetUniformLocation("in_MVPMatrix");
GLint colourLocation = shader->GetUniformLocation("in_colour");
GLint textureLocation = shader->GetUniformLocation("texMap");
glUniformMatrix4fv( MVPMatrixLocation, 1, GL_FALSE, glm::value_ptr( modelViewProjMatrix ) );
glUniform4fv( colourLocation, 1, glm::value_ptr( _colour ) );
// Texture Uniform
if( texture != 0 )
{
glActiveTexture( GL_TEXTURE0 );
glUniform1i( textureLocation, 0 );
glBindTexture( GL_TEXTURE_2D, texture->GetTextureId() );
}
glDrawElements( GL_TRIANGLES, _numIndices, GL_UNSIGNED_INT, (void*) 0 );
glDisableVertexAttribArray( posLocation );
glDisableVertexAttribArray( texCoordLocation );
shader->UnbindShader();
glBindVertexArray( 0 );
-垂直着色器
#version 150
in vec3 in_position;
in vec2 in_texCoord;
out vec4 out_colour;
smooth out vec2 out_texCoord;
uniform vec4 in_colour;
uniform mat4 in_MVPMatrix;
void main()
{
out_colour = in_colour;
out_texCoord = in_texCoord;
gl_Position = in_MVPMatrix * vec4( in_position, 1.0 );
}
-碎片着色器
#version 150
in vec4 out_colour;
smooth in vec2 out_texCoord;
out vec4 fragColor;
uniform sampler2D texMap;
void main()
{
vec4 diffuseTexel = texture2D( texMap, out_texCoord );
fragColor = out_colour * diffuseTexel;
}