我正试图跟踪我的手然后每个x,我会在openGL窗口上画一个点。
这是我的代码:
#include "GraphicsEffects.h"
#include "Errors.h"
GraphicsEffects::GraphicsEffects():
_vboID(0)
{}
void GraphicsEffects::init(){
SDL_Init(SDL_INIT_EVERYTHING);
_window = SDL_CreateWindow("2D Painting", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED , 600, 600, SDL_WINDOW_OPENGL);
if(_window == nullptr){
fatalError("SDL window could not be created! "); }
SDL_GLContext glContext = SDL_GL_CreateContext(_window);
if(glContext == nullptr) {
fatalError("SDL_GL context could not be created!");
}
GLenum error = glewInit();
if(error != GLEW_OK){
fatalError("Could not initialize glew!");
}
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
if(_vboID == 0){
glGenBuffers(1, &_vboID);
}
_colorProgram.compileShaders("Shaders/color.vert", "Shaders/color.frag");
_colorProgram.addAttribute("vertexPosition");
_colorProgram.linkShaders();
}
void GraphicsEffects::draw(int x, int y){
int pointData[2];
pointData[0] = x;
pointData[1] = y;
glClearDepth(1.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
_colorProgram.use();
glBindBuffer(GL_ARRAY_BUFFER, _vboID);
glBufferData(GL_ARRAY_BUFFER, sizeof(pointData), pointData, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 2, GL_INT, GL_FALSE, 0, 0);
glDrawArrays(GL_POINT, 0, 1);
glBindBuffer(GL_ARRAY_BUFFER, 0);
_colorProgram.unuse();
SDL_GL_SwapWindow(_window);
}
对于Shaders / color.vert:“顶点着色器文件”
#version 130
in vec2 vertexPosition;
void main() {
gl_Position.xy = vertexPosition;
gl_Position.z = 0;
gl_Position.w = 1.0;
}
for Shader / color.frag:“fragment shader”
#version 130
out vec4 color ;
void main() {
color = vec4(1.0, 1.0, 0.0, 1.0);
}
我预计我会用我的(x,y)动作得分,但窗户上什么都没有出现!
答案 0 :(得分:0)
这一行
glDrawArrays(GL_POINT, 0, 1);
将生成GL_INVALID_ENUM
错误,不执行任何其他操作。正确的值为GL_POINTS
,而不是GL_POINT
。
您应该添加错误检查,至少对于开发版本。如果可能,请查看debug output functionality较新的OpenGL版本。