VBO::VBO(const VBO& vbo) :
m_data_size(vbo.m_data_size),
m_nbElts(vbo.m_nbElts),
m_lock(false)
{
unsigned int nbbytes = sizeof(float) * m_data_size * m_nbElts;
glGenBuffers(1, &(*m_id));
vbo.bind();
void* src = glMapBuffer(GL_ARRAY_BUFFER, GL_READ_WRITE);
bind();
glBufferData(GL_ARRAY_BUFFER, nbbytes, src, GL_STREAM_DRAW);
vbo.bind();
glUnmapBuffer(GL_ARRAY_BUFFER);
}
TEST_F(TransformFeedbackTest, test)
{
std::ifstream vsFile("data/transform_feedback.vert");
std::ifstream gsFile("data/transform_feedback.geom");
Shader vertex(GL_VERTEX_SHADER);
Shader geometry(GL_GEOMETRY_SHADER);
ShaderProgram shader;
Query query(GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN);
VAO vao;
VBO vbo;
TFBO tfbo;
const GLchar* feedbackVaryings[] = { "outValue" };
GLfloat data[] = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f };
GLfloat feedback[15];
GLuint primitives;
ASSERT_TRUE(vertex.compile(vsFile));
ASSERT_TRUE(geometry.compile(gsFile));
shader.attach(vertex);
shader.attach(geometry);
shader.setTransformFeedbackVaryings(1, feedbackVaryings, GL_INTERLEAVED_ATTRIBS);
ASSERT_TRUE(shader.link());
shader.use();
shader.printDebug();
vao.bind();
vbo.bind();
vbo.setData(sizeof(data), data, GL_STATIC_DRAW);
GLint inputAttrib = shader.getAttribLocation("inValue");
vao.enableAttrib(inputAttrib);
glVertexAttribPointer(inputAttrib, 1, GL_FLOAT, GL_FALSE, 0, 0);
tfbo.setData(sizeof(data) * 3, nullptr, GL_STATIC_READ);
tfbo.bindBufferBase(0);
mogl::enable(GL_RASTERIZER_DISCARD);
query.begin();
TransformFeedback::begin(GL_TRIANGLES);
glDrawArrays(GL_POINTS, 0, 5);
TransformFeedback::end();
query.end();
mogl::disable(GL_RASTERIZER_DISCARD);
mogl::Sync::flush();
primitives = query.get<GLuint>(GL_QUERY_RESULT);
tfbo.getSubData(0, sizeof(feedback), feedback);
std::cout << primitives << " primitives written" << std::endl;
for (unsigned int i = 0; i < 15; ++i)
std::cout << feedback[i] << std::endl;
}