我正在尝试随着时间的推移旋转和转换我的单个三角形。我已经编写了main.cpp文件,并为我的顶点和片段着色器源码编写了单独的文件。
下面是我的main.cpp文件中的代码。
void framebuffer_size_callback(GFLWwindow* window, int width, int height);
void processInput(GLFWwindow *window);
// Shaders
const char *vertexShaderSource =
"#version 410\n"
"in vec3 vp;\n"
"void main()\n"
"{\n"
"gl_Position = vec4(aPos, 1.0);\n"
"}\0";
const char *fragmentShaderSource =
"#version 410\n"
"out vec4 FragColor;\n"
"in vec3 myColor;\n"
"void main()\n"
"{\n"
"FragColor = vec4(myColor, 1.0f);\n"
"}\n\0";
int main ()
{
// start GL context and O/S window using the GLFW helper library
if (!glfwInit ())
{
fprintf (stderr, "ERROR: could not start GLFW3\n");
return 1;
}
// uncomment these lines if on Apple OS X
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
GLFWwindow* window = glfwCreateWindow(640, 480, "LearnOpenGL", NULL, NULL);
if (!window)
{
fprintf(stderr, "ERROR: could not open window with GLFW3\n");
glfwTerminate();
return 1;
}
glfwMakeContextCurrent(window);
// start GLEW extension handler
glewExperimental = GL_TRUE;
glewInit();
// get version info
const GLubyte* renderer = glGetString(GL_RENDERER);
const GLubyte* version = glGetString(GL_VERSION);
printf("Renderer: %s\n", renderer);
printf("OpenGL version supported %s\n", version);
glEnable(GL_DEPTH_TEST); // enable depth-testing
glDepthFunc(GL_LESS);
// Draw a single triangle
float points[] = {
// positions // colors
0.0f, 0.5f, 0.0f, 1.0f, 0.0f, 0.0f,
0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f,
-0.5f, -0.5f, 0.0f, 0.0f 0.0f, 1.0f
};
GLuint VBO = 0;
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(points), points, GL_STATIC_DRAW);
// Generate a VAO.
GLuint VAO = 0;
glGenVertexArrays(1, &VAO);
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(points), points, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray(0);
// Compile a Vertex Shader
int vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShader);
// Compile a fragment shader.
int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
glCompileShader(fragmentShader);
// Compile shaders into a executable shader program.
int shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, fragmentShader);
glAttachShader(shaderProgram, vertexShader);
glLinkProgram(shaderProgram);
// Create another float array to make my triangle fan.
float points_5_triangles[] = {
-0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f,
0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f,
0.0f, 0.5f, 0.0f, 1.0f, 2.0f, 0.5f,
// Another triangle made from point 1, 3, and 4
-0.5f,
}
// Generate another VBO for my Triangle Fan
GLuint VBO_5_triangles = 0;
glGenBuffers(1, &VBO_5_triangles);
glBindBuffer(GL_ARRAY_BUFFER, VBO_5_triangles);
glBufferData(GL_ARRAY_BUFFER, sizeof(points_5_triangles), points_5_triangles, GL_STATIC_DRAW);
// Generate another VAO for my Triangle Fan
GLuint VAO_5_triangles = 0;
glGenVertexArrays(1, &VAO_5_triangles);
glBindVertexArray(VAO_5_triangles);
glBindBuffer(GL_ARRAY_BUFFER, VBO_5_triangles);
glBufferData(GL_ARRAY_BUFFER, sizeof(points_5_triangles), points_5_triangles, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray(0);
// Drawing the triangles aka render loop
while (!glfwWindowShouldClose(window))
{
processInput(window);
// wipe the drawing surface clear
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// Draw Triangle
glUseProgram(shaderProgram);
glBindVertexArray(VAO);
glDrawArrays(GL_TRIANGLES, 0, 3);
// Draw Triangle Fan
glBindVertexArray(VAO_5_triangles);
glDrawArrays(GL_TRIANGLE_FAN, 0, 7);
// swap buffers and poll IO events
glfwPollEvents();
glfwSwapBuffers(window);
}
// close GL context and any other GLFW resources
glfwTerminate();
return 0;
}
我所遵循的教程确实介绍了变换的内容 但在它所使用的例子中 三角形既有纹理也有着色器。为了达到我的目的,我想在我的代码中不添加纹理。
谁能教我如何在我的 "单个三角形 "中添加2个变换:平移和旋转,如这段代码所示?
你的三角形是否有纹理与转换无关。
你只需计算一个变换矩阵,将其传递给你的顶点着色器并与你的坐标相乘,就可以旋转你的三角形。
你的顶点着色器应该看起来像这样。
const char *vertexShaderSource =
"#version 410\n"
"layout (location = 0) in vec3 vp;\n"
"uniform mat4 transform;"
"void main()\n"
"{\n"
" gl_Position = transform * vec4(vp, 1.0);\n"
"}\0";
我建议你用glm库来实现这个功能 你计算出你的矩阵,然后像这样传递给你的着色器。
auto transformMatrix = glm::rotate( /* your rotation calculation */ );
auto transLoc = glGetUniformLocation(shaderProgram, "transform");
glUniformMatrix4fv(transLoc , 1, GL_FALSE, glm::value_ptr(transformMatrix));