OpenGL

Question

所以我终于正确设置了 opengl window 并使用 vaos、vbos 和 glDrawElements() 等显示了三角形

但现在我遇到了新问题 - 无法让着色器工作。我还不太了解他们。我希望片段着色器显示我放入单独缓冲区对象中的顶点颜色。

示例代码：

const char* vertexShaderSource = 
    "#program 330\n"
    "layout(location = 0) in vec2 position;\n"
    "layout(location = 1) in vec3 color;\n"
    "out vec4 fragColor;\n"
    "void main(void){\n"
    "gl_Position = vec4(position, 0.0, 1.0);\n"
    "fragColor = vec4(color, 1.0);\n"
    "}";

const char* fragShaderSource =
    "#program 330\n"
    "in vec4 fragColor;\n"
    "out vec4 outColor;\n"
    "void main(void){\n"
    "outColor = fragColor;\n"
    "}";

GLuint programID = glCreateProgram();
GLuint vertexShaderID = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShaderID, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShaderID);

GLuint fragShaderID = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragShaderID, 1, &fragShaderSource, NULL);
glCompileShader(fragShaderID);

glAttachShader(programID, vertexShaderID);
glAttachShader(programID, fragShaderID);
glLinkProgram(programID);
glValidateProgram(programID);

GLfloat vertexPositions[8] = 
{
    -0.5f, 0.5f,
    0.5f, 0.5f,
    -0.5f, -0.5f,
    0.5f, -0.5f,
};

GLfloat colors[18] = 
{
    1.0f, 0.0f, 0.0f,
    0.0f, 1.0f, 0.0f,
    0.0f, 0.0f, 1.0f,

    0.0f, 1.0f, 0.0f,
    1.0f, 0.0f, 0.0f,
    0.0f, 0.0f, 1.0f,
};

GLushort indices[6] =
{
    0, 1, 2,
    1, 3, 2
};

GLuint vao;
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);

GLuint vbo; //Vertices
glGenBuffers(1, &vbo);
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 8, vertexPositions, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, 0);

GLuint cbo; //Colors
glGenBuffers(1, &cbo);
glBindBuffer(GL_ARRAY_BUFFER, cbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 18, colors, GL_STATIC_DRAW);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, 0);

GLuint ibo; //Indexes
glGenBuffers(1, &ibo);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GLushort) * 6, indices, GL_STATIC_DRAW);

并渲染：

while(..)
{
    ..clear

    glBindVertexArray(vao);
    glUseProgram(programID);

    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, (void*)(0));

    ..update
}

除了着色器之外，一切似乎都运行良好。任何帮助表示赞赏:) 谢谢

Answer 1

在每个着色器中，将 "#program 330\n" 更改为 "#version 330\n"。这就是您指定要使用哪个 GLSL 版本的方式。

OpenGL - 无法让着色器显示顶点颜色

OpenGL - Can't get shader to display vertex colors

shader

vertex-attributes

vao