void TestGame::engine_render() {
buffer_clear();
static float rot = 0;
rot += PI / 120;
if (rot > 4 * PI)
rot -= 4 * PI;
camera_.x = (float)sin(rot) * 2.5f;
camera_.y = -0.3f;
camera_.z = (float)cos(rot) * 2.5f;
Matrix4 viewMatrix = matrix_look_at(camera_, Vector3(0, 0, 0), vector_up());
Matrix4 projectionMatrix = matrix_perspective(0.1f,
((float)ENGINE_WIDTH) / ENGINE_HEIGHT, 0.01f, 1.0f);
for (int i = 0; i < meshes_count_; i++) {
Matrix4 transform = meshes_[i].world * viewMatrix * projectionMatrix;
for (int j = 0; j < meshes_[i].face_count; j++)
draw_triangle(
project(meshes_[i].vertices[meshes_[i].faces[j].a], transform),
project(meshes_[i].vertices[meshes_[i].faces[j].b], transform),
project(meshes_[i].vertices[meshes_[i].faces[j].c], transform),
meshes_[i].texture);
}
}
//3D viewing pipeline. VTM is complete view matrix. none of the values of the View structure should be edited.
void matrix_setView3D(Matrix *vtm, View3D *view){
Vector u, vup, vpn;
double b, d;
matrix_identity(vtm);
matrix_translate(vtm, -view->vrp.val[0], -view->vrp.val[1], -view->vrp.val[2]);
vpn = view->vpn;
vector_cross(&view->vup, &vpn, &u);
vector_cross(&vpn, &u, &vup);
vector_normalize(&u);
vector_normalize(&vup);
vector_normalize(&vpn);
matrix_rotateXYZ(vtm, &u, &vup, &vpn);
matrix_translate(vtm, 0.0, 0.0, view->d);
// in lecture notes here (6 and 7) it says to shear but as we only have d to define the COP I don't think we have to
b = view->d + view->b;
matrix_scale(vtm, ((2.0*view->d) / (b*view->du)), ((2.0*view->d) / (b*view->dv)), (1/b));
d = view->d / b;
matrix_perspective(vtm, d);
matrix_scale2D(vtm, (-view->screenx / (2.0*d)), (-view->screeny / (2.0*d)));
matrix_translate2D(vtm, (view->screenx / 2.0), (view->screeny / 2.0));
}
int main(int argc, char *argv[]){
//glfwSetKeyCallback(window, &keypress);
GLFWwindow *window;
GLuint VAO, VBO;
GLuint program;
GLuint crate;
matrix camera, perspective, rotate, scale, translate;
GLuint l_camera, l_rotate, l_scale, l_translate, l_time, l_perspective;
float time;
// init window
window = dg_window(1920-192, 1080-108, "OpenGL Experiment");
// init shaders
dg_program(&program);
dg_attach("vertex.glsl", GL_VERTEX_SHADER);
dg_attach("fragment.glsl", GL_FRAGMENT_SHADER);
dg_compile();
// init texture
crate = dg_texture("crate.jpg");
// init model
glGenBuffers(1, &VBO);
glGenVertexArrays(1, &VAO);
glBindVertexArray(VAO);
glEnable(GL_DEPTH_TEST);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(MODEL_CUBE), MODEL_CUBE, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)(0));
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)(3*sizeof(GLfloat)));
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glBindVertexArray(0);
// locate shader variables
l_scale = glGetUniformLocation(program, "scale");
l_camera = glGetUniformLocation(program, "camera");
l_rotate = glGetUniformLocation(program, "rotate");
l_translate = glGetUniformLocation(program, "translate");
l_perspective = glGetUniformLocation(program, "perspective");
// init matrices
matrix_perspective(&perspective, 90.0f, 90.0f, 0.1f, 100.0f);
matrix_identity(&rotate);
matrix_identity(&scale);
matrix_identity(&translate);
//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); // uncomment for wireframe
while(!glfwWindowShouldClose(window)){
glfwPollEvents();
time = (float)(glfwGetTime() * 100);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
//eye target up
matrix_camera(&camera,
// position
0.0f, 0.0f, 0.0f,
// angle
0.0f, 0.0f, 0.0f
);
glUseProgram(program);
// send to gpu
glUniform1f(l_time, time);
glUniformMatrix4fv(l_camera, 1, GL_TRUE, camera.data);
glUniformMatrix4fv(l_perspective, 1, GL_TRUE, perspective.data);
// bind model
glBindVertexArray(VAO);
// calculate transformations
matrix_scale(&scale, 1.0f, 1.0f, 1.0f);
matrix_rotate_y(&rotate, time);
matrix_translate(&translate, 0.0f, 0.0f, -1.0f);
// send to gpu
glUniformMatrix4fv(l_scale, 1, GL_TRUE, scale.data);
glUniformMatrix4fv(l_rotate, 1, GL_TRUE, rotate.data);
glUniformMatrix4fv(l_translate, 1, GL_TRUE, translate.data);
// texture
glBindTexture(GL_TEXTURE_2D, crate);
// draw
glDrawArrays(GL_TRIANGLES, 0, 36);
// unbind model VAO
glBindVertexArray(0);
glfwSwapBuffers(window);
}
glfwTerminate();
return EXIT_SUCCESS;
}
