void MyView::
windowViewWillStart(std::shared_ptr<tygra::Window> window)
{
/*
* Compile shaders and create a shader program
*/
GLint compile_status = 0;
GLuint vertex_shader = glCreateShader(GL_VERTEX_SHADER);
std::string vertex_shader_string = tygra::stringFromFile("water_vs.glsl");
const char *vertex_shader_code = vertex_shader_string.c_str();
glShaderSource(vertex_shader, 1,
(const GLchar **) &vertex_shader_code, NULL);
glCompileShader(vertex_shader);
glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &compile_status);
if (compile_status != GL_TRUE) {
const int string_length = 1024;
GLchar log[string_length]= "";
glGetShaderInfoLog(vertex_shader, string_length, NULL, log);
std::cerr << log << std::endl;
}
GLuint fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
std::string fragment_shader_string = tygra::stringFromFile("water_fs.glsl");
const char *fragment_shader_code = fragment_shader_string.c_str();
glShaderSource(fragment_shader, 1,
(const GLchar **) &fragment_shader_code, NULL);
glCompileShader(fragment_shader);
glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &compile_status);
if (compile_status != GL_TRUE) {
const int string_length = 1024;
GLchar log[string_length]= "";
glGetShaderInfoLog(fragment_shader, string_length, NULL, log);
std::cerr << log << std::endl;
}
water_sp_ = glCreateProgram();
glAttachShader(water_sp_, vertex_shader);
glBindAttribLocation(water_sp_, kVertexPosition, "vertex_position");
glDeleteShader(vertex_shader);
glAttachShader(water_sp_, fragment_shader);
glBindFragDataLocation(water_sp_, 0, "fragment_colour");
glDeleteShader(fragment_shader);
glLinkProgram(water_sp_);
GLint link_status = 0;
glGetProgramiv(water_sp_, GL_LINK_STATUS, &link_status);
if (link_status != GL_TRUE) {
const int string_length = 1024;
GLchar log[string_length]= "";
glGetProgramInfoLog(water_sp_, string_length, NULL, log);
std::cerr << log << std::endl;
}
/*
* TODO: Create vertex buffers and a vertex array object for the water mesh
*/
std::vector<int> elements(waterSim_->IndexCount());
waterSim_->GetIndices(elements.data());
glGenBuffers(1, &waterMesh_.position_vbo);
glBindBuffer(GL_ARRAY_BUFFER, waterMesh_.position_vbo);
glBufferData(GL_ARRAY_BUFFER, waterSim_->VertexCount() * sizeof(glm::vec3), nullptr, GL_DYNAMIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glGenBuffers(1, &waterMesh_.normal_vbo);
glBindBuffer(GL_ARRAY_BUFFER, waterMesh_.normal_vbo);
glBufferData(GL_ARRAY_BUFFER, waterSim_->VertexCount() * sizeof(glm::vec3), nullptr, GL_DYNAMIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glGenBuffers(1, &waterMesh_.tex_coord_vbo);
glBindBuffer(GL_ARRAY_BUFFER, waterMesh_.tex_coord_vbo);
glBufferData(GL_ARRAY_BUFFER, waterSim_->VertexCount() * sizeof(glm::vec3), nullptr, GL_DYNAMIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glGenBuffers(1, &waterMesh_.element_vbo);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, waterMesh_.element_vbo);
glBufferData(GL_ELEMENT_ARRAY_BUFFER,
elements.size() * sizeof(unsigned int),
elements.data(),
GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
waterMesh_.element_count = elements.size();
glGenVertexArrays(1, &waterMesh_.vao);
glBindVertexArray(waterMesh_.vao);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, waterMesh_.element_vbo);
glBindBuffer(GL_ARRAY_BUFFER, waterMesh_.position_vbo);
glEnableVertexAttribArray(kVertexPosition);
glVertexAttribPointer(kVertexPosition, 3, GL_FLOAT, GL_FALSE, sizeof(glm::vec3), TGL_BUFFER_OFFSET(0));
glBindBuffer(GL_ARRAY_BUFFER, waterMesh_.normal_vbo);
glEnableVertexAttribArray(kVertexNormal);
glVertexAttribPointer(kVertexNormal, 3, GL_FLOAT, GL_FALSE, sizeof(glm::vec3), TGL_BUFFER_OFFSET(1));
glBindBuffer(GL_ARRAY_BUFFER, waterMesh_.tex_coord_vbo);
glEnableVertexAttribArray(kVertexTexcoord);
glVertexAttribPointer(kVertexTexcoord, 3, GL_FLOAT, GL_FALSE, sizeof(glm::vec3), TGL_BUFFER_OFFSET(2));
glBufferData(GL_ELEMENT_ARRAY_BUFFER, elements.size() * sizeof(unsigned int), elements.data(), GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}
/*
* \brief Create the mesh
*/
void Mesh::Create(
Vertex *vertices, //! A pointer to an array of verticies
const int noofVerticies, //! The number of verticies in the above array
unsigned int *elements, //! A pointer to an array of elements
const int noofElements //! The number of elements in the above array
)
{
// verticies
glGenVertexArrays(1, &m_vao);
glBindVertexArray(m_vao);
glGenBuffers(1, &m_vertexVBO);
glBindBuffer(GL_ARRAY_BUFFER, m_vertexVBO);
glBufferData(
GL_ARRAY_BUFFER,
noofVerticies * sizeof(Vertex),
vertices,
GL_STATIC_DRAW
);
m_vertexCount = noofVerticies;
// positon
glEnableVertexAttribArray(0);
glVertexAttribPointer(
0,
3,
GL_FLOAT,
GL_FALSE,
sizeof(Vertex),
TGL_BUFFER_OFFSET(0)
);
// normal
glEnableVertexAttribArray(1);
glVertexAttribPointer(
1,
3,
GL_FLOAT,
GL_FALSE,
sizeof(Vertex),
TGL_BUFFER_OFFSET(3 * sizeof(float))
);
// tangents
glEnableVertexAttribArray(2);
glVertexAttribPointer(
2,
3,
GL_FLOAT,
GL_FALSE,
sizeof(Vertex),
TGL_BUFFER_OFFSET(6 * sizeof(float))
);
// tex-coords
glEnableVertexAttribArray(3);
glVertexAttribPointer(
3,
2,
GL_FLOAT,
GL_FALSE,
sizeof(Vertex),
TGL_BUFFER_OFFSET(9 * sizeof(float))
);
// elements
glGenBuffers(1, &m_elementVBO);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_elementVBO);
glBufferData(
GL_ELEMENT_ARRAY_BUFFER,
noofElements * sizeof(unsigned int),
elements,
GL_STATIC_DRAW
);
m_elementCount = noofElements;
}