instanced_cubes.c récupéré (pour étude)
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#include <epoxy/gl.h>
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#include <cglm/cglm.h>
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#include <stdlib.h>
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#include <time.h>
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#include <gdk/gdk.h> // General GDK events and types
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#include <gtk/gtk.h> // GTK types
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#define N_INSTANCE 5
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#define N_SPACE_SIZE 20
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GtkWidget *window;
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// OpenGL objects
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GLuint vao, vbo, ebo, instance_vbo, arrow_instance_vbo;
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GLuint arrow_vao, arrow_vbo, arrow_ebo;
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GLuint edge_ebo;
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GLuint shader_program;
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unsigned int num_instances = N_INSTANCE;
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mat4 instance_matrices[N_INSTANCE];
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static float pitch = 0.0f, yaw = -90.0f; // Initial angles for camera orientation
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static const float sensitivity = 4.0f; // Adjust this for smoother mouse control
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static float lastX = 400, lastY = 300; // Initial cursor position (center of the screen)
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static float fov = 45.0f; // Field of View for zoom control
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static gboolean firstMouse = TRUE; // To handle first mouse movement
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static float rotation_angle_x = 0.0f; // Rotation angle around the X-axis
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static float rotation_angle_y = 0.0f; // Rotation angle around the Y-axis
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static float rotation_angle_z = 0.0f; // Rotation angle around the Z-axis
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static mat4 rotation_matrix;
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static bool rotate;
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// Projection and view matrices
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mat4 projection, view;
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// Function Prototypes
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GLuint create_shader_program ();
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void setup_buffers ();
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void setup_arrow_buffers ();
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void setup_instance_data ();
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void setup_arrow_instance_data();
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static void on_realize (GtkGLArea *area);
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static gboolean on_render (GtkGLArea *area, GdkGLContext *context);
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static void on_activate (GtkApplication *app, gpointer user_data);
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static gboolean on_mouse_scroll(GtkEventControllerScroll *controller, gdouble dx, gdouble dy, gpointer user_data);
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static gboolean on_mouse_move(GtkEventControllerMotion *controller, gdouble x, gdouble y, gpointer user_data);
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// Vertex and fragment shader source code
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const char *vertex_shader_src = "#version 460 core\n"
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"layout (location = 0) in vec3 aPos;\n"
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"layout (location = 2) in mat4 instanceMatrix;\n"
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"uniform mat4 projection;\n"
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"uniform mat4 view;\n"
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"void main() {\n"
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" gl_Position = projection * view * instanceMatrix * vec4(aPos, 1.0);\n"
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"}\n";
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const char *fragment_shader_src = "#version 460 core\n"
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"uniform vec4 FragColor;\n"
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"out vec4 finalColor;\n"
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"void main() {\n"
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" finalColor = vec4(FragColor.rgb, 0.3); // Set alpha to 30%\n"
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"}\n";
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// Cube vertices and indices
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GLfloat vertices[] = {
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-0.5f, -0.5f, -0.5f, // 0
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0.5f, -0.5f, -0.5f, // 1
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0.5f, 0.5f, -0.5f, // 2
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-0.5f, 0.5f, -0.5f, // 3
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-0.5f, -0.5f, 0.5f, // 4
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0.5f, -0.5f, 0.5f, // 5
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0.5f, 0.5f, 0.5f, // 6
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-0.5f, 0.5f, 0.5f // 7
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};
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GLuint indices[] = {
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4, 5, 6, 6, 7, 4, // Front face
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0, 3, 2, 2, 1, 0, // Back face
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0, 4, 7, 7, 3, 0, // Left face
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1, 2, 6, 6, 5, 1, // Right face
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3, 7, 6, 6, 2, 3, // Top face
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0, 1, 5, 5, 4, 0 // Bottom face
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};
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GLuint edge_indices[] = {
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// Bottom edges
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0, 1,
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1, 5,
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5, 4,
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4, 0,
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// Top edges
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3, 2,
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2, 6,
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6, 7,
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7, 3,
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// Vertical edges
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0, 3,
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1, 2,
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5, 6,
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4, 7
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};
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GLfloat arrow_vertices[] = {
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0.0f, 0.0f, 0.0f, // Center of cube
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0.5f, 0.0f, 0.0f, // Right face
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-0.5f, 0.0f, 0.0f, // Left face
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0.0f, 0.5f, 0.0f, // Top face
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0.0f, -0.5f, 0.0f, // Bottom face
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0.0f, 0.0f, 0.5f, // Front face
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0.0f, 0.0f, -0.5f // Back face
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};
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GLuint arrow_indices[] = {
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0, 1, // Center to Right face
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0, 2, // Center to Left face
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0, 3, // Center to Top face
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0, 4, // Center to Bottom face
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0, 5, // Center to Front face
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0, 6 // Center to Back face
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};
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// Maps a 2D point on the screen to a 3D point on a virtual trackball (sphere)
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void trackball_map(float x, float y, int width, int height, vec3 out)
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{
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// Normalize x and y to the range [-1, 1]
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float normalized_x = (2.0f * x - width) / width;
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float normalized_y = (height - 2.0f * y) / height; // Inverted y axis
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// Compute the distance from the origin
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float d = sqrtf(normalized_x * normalized_x + normalized_y * normalized_y);
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// Clamp the distance to 1 (the edge of the virtual trackball)
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if (d > 1.0f) d = 1.0f;
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// Compute the z coordinate based on the spherical projection
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float z = sqrtf(1.0f - d * d);
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// The output 3D point
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out[0] = normalized_x;
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out[1] = normalized_y;
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out[2] = z;
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}
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static gboolean on_mouse_move(GtkEventControllerMotion *controller, gdouble x, gdouble y, gpointer user_data)
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{
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GdkModifierType state = gtk_event_controller_get_current_event_state(GTK_EVENT_CONTROLLER(controller));
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if (state & GDK_BUTTON1_MASK) { // If the left mouse button is held
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// Define screen width and height (adjust accordingly)
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int width = gtk_widget_get_width(window);
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int height = gtk_widget_get_height(window);
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// Variables to store trackball positions
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vec3 last_pos, cur_pos;
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// Map the last and current mouse positions to the virtual trackball
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trackball_map(lastX, lastY, width, height, last_pos);
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trackball_map(x, y, width, height, cur_pos);
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lastX = x;
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lastY = y;
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// Calculate the rotation axis as the cross product between the last and current positions
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vec3 axis;
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glm_vec3_cross(last_pos, cur_pos, axis);
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// Calculate the angle of rotation based on the distance moved by the mouse
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float angle = acosf(fmin(1.0f, glm_vec3_dot(last_pos, cur_pos)));
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// Apply the rotation using the axis-angle method
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if (angle > 0.001f) { // Avoid very small rotations
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mat4 temp_rotation;
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glm_mat4_identity(temp_rotation); // Initialize a temporary rotation matrix
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glm_rotate(temp_rotation, angle * sensitivity, axis); // Rotate around the computed axis
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glm_mul(temp_rotation, rotation_matrix, rotation_matrix); // Accumulate the rotation
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}
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// Request to redraw the scene with the updated rotation
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gtk_widget_queue_draw(GTK_WIDGET(user_data));
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}
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rotate = TRUE;
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return TRUE;
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}
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static gboolean on_mouse_scroll(GtkEventControllerScroll *controller, gdouble dx, gdouble dy, gpointer user_data)
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{
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if (dy > 0)
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fov -= 2.0f;
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else if (dy < 0)
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fov += 2.0f;
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// Clamp the field of view to avoid extreme zooms
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if (fov < 10.0f) fov = 10.0f;
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if (fov > 90.0f) fov = 90.0f;
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// Update the projection matrix with the new FOV
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glm_perspective(glm_rad(fov), 800.0f / 600.0f, 0.1f, 100.0f, projection);
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// Recalculate the view matrix for zoom (moving the camera in/out)
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glm_lookat((vec3){0.0f, 0.0f, 20.0f}, (vec3){0.0f, 0.0f, 0.0f}, (vec3){0.0f, 1.0f, 0.0f}, view);
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gtk_widget_queue_draw(GTK_WIDGET(user_data)); // Request to redraw the scene
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return TRUE;
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}
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// Called when GtkApplication is activated
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static void on_activate (GtkApplication *app, gpointer user_data)
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{
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g_message("[%s] activation in progress...",
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__func__);
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window = gtk_application_window_new(app);
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gtk_window_set_title(GTK_WINDOW(window), "OpenGL 4.6 experiment");
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gtk_window_set_default_size(GTK_WINDOW(window), 800, 600);
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g_message("[%s] window created",
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__func__);
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GtkWidget *gl_area = gtk_gl_area_new();
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gtk_gl_area_set_required_version(GTK_GL_AREA(gl_area), 4, 6);
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gtk_gl_area_set_has_depth_buffer(GTK_GL_AREA(gl_area), TRUE);
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gtk_gl_area_set_auto_render(GTK_GL_AREA(gl_area), TRUE);
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g_message("[%s] GLArea created",
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__func__);
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g_signal_connect(gl_area, "realize", G_CALLBACK(on_realize), NULL);
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g_signal_connect(gl_area, "render", G_CALLBACK(on_render), NULL);
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g_message("[%s] GLArea signals linked",
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__func__);
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// Create and add motion event controller
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GtkEventController *motion_controller = gtk_event_controller_motion_new();
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g_signal_connect(motion_controller, "motion", G_CALLBACK(on_mouse_move), gl_area); // Pass gl_area as user_data
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gtk_widget_add_controller(gl_area, GTK_EVENT_CONTROLLER(motion_controller));
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// Create and add scroll event controller
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GtkEventController *scroll_controller = gtk_event_controller_scroll_new(GTK_EVENT_CONTROLLER_SCROLL_BOTH_AXES);
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g_signal_connect(scroll_controller, "scroll", G_CALLBACK(on_mouse_scroll), gl_area); // Pass gl_area as user_data
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gtk_widget_add_controller(gl_area, GTK_EVENT_CONTROLLER(scroll_controller));
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g_message("[%s] Mouse events now linked to signals",
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__func__);
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gtk_window_set_child(GTK_WINDOW(window), gl_area);
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gtk_widget_set_visible(window, TRUE);
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g_message("[%s] GLArea set visible",
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__func__);
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}
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// Called when GtkGLArea is realized (OpenGL context is created)
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static void on_realize(GtkGLArea *area)
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{
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g_message("[%s] GLArea realization in progress...", __func__);
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gtk_gl_area_make_current(GTK_GL_AREA(area));
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g_message("[%s] GLArea made current", __func__);
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if (gtk_gl_area_get_error(GTK_GL_AREA(area)) != NULL) return;
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g_message("[%s] OpenGL context successfully created", __func__);
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// Enable depth testing
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glEnable(GL_DEPTH_TEST);
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glEnable(GL_BLEND);
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glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
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glDepthFunc(GL_LESS);
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// Initialize cglm projection and view matrices
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glm_mat4_identity(projection);
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glm_perspective(glm_rad(60.0f), 800.0f / 600.0f, 0.1f, 100.0f, projection);
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glm_mat4_identity(view);
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glm_lookat((vec3){0.0f, 0.0f, 20.0f}, (vec3){0.0f, 0.0f, 0.0f}, (vec3){0.0f, 1.0f, 0.0f}, view);
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// Initialize rotation matrix
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glm_mat4_identity(rotation_matrix); // Initialize to identity
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// Create shader program and setup buffers
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shader_program = create_shader_program();
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setup_buffers();
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setup_arrow_buffers();
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setup_instance_data();
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setup_arrow_instance_data(); // Setup arrow data
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// Set the background color
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glClearColor(0.1f, 0.1f, 0.1f, 1.0f); // Dark gray background
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glLineWidth(2.0f); // Increase the line width for cube edges
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}
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// Called on each frame to render the scene
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static gboolean on_render(GtkGLArea *area, GdkGLContext *context)
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{
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glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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glEnable(GL_DEPTH_TEST);
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glDepthFunc(GL_LESS);
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glUseProgram(shader_program);
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// Pass projection and view matrices to the shader
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GLint projectionLoc = glGetUniformLocation(shader_program, "projection");
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GLint viewLoc = glGetUniformLocation(shader_program, "view");
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glUniformMatrix4fv(projectionLoc, 1, GL_FALSE, (const GLfloat *)projection);
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glUniformMatrix4fv(viewLoc, 1, GL_FALSE, (const GLfloat *)view);
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// Update instance matrices with the accumulated rotation matrix
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if (rotate) {
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for (unsigned int i = 0; i < num_instances; i++) {
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mat4 model;
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glm_mat4_copy(rotation_matrix, model); // Copy the accumulated rotation matrix
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// Combine the rotation with the instance's individual matrix
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glm_mul(model, instance_matrices[i], instance_matrices[i]);
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}
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rotate = FALSE;
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}
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// Update the instance matrix buffer with the modified instance matrices
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glBindBuffer(GL_ARRAY_BUFFER, instance_vbo);
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glBufferSubData(GL_ARRAY_BUFFER, 0, num_instances * sizeof(mat4), instance_matrices);
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// Draw the cubes with the updated instance matrices
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glUniform4f(glGetUniformLocation(shader_program, "FragColor"), 0.4f, 0.6f, 0.9f, 1.0f);
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glBindVertexArray(vao);
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glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
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glDrawElementsInstanced(GL_TRIANGLES, 36, GL_UNSIGNED_INT, 0, num_instances);
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// Draw the cube edges
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glUniform4f(glGetUniformLocation(shader_program, "FragColor"), 1.0f, 1.0f, 1.0f, 1.0f);
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glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, edge_ebo);
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glDrawElementsInstanced(GL_LINES, 24, GL_UNSIGNED_INT, 0, num_instances);
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glDisable(GL_DEPTH_TEST);
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// Set arrow color (e.g., red) and draw arrows
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glUniform4f(glGetUniformLocation(shader_program, "FragColor"), 1.0f, 0.0f, 0.0f, 1.0f); // Red, opaque
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glBindVertexArray(arrow_vao);
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glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, arrow_ebo);
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glDrawElementsInstanced(GL_LINES, 12, GL_UNSIGNED_INT, 0, num_instances);
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glEnable(GL_DEPTH_TEST);
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glBindVertexArray(0);
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// Reset the rotation matrix to prevent continuous accumulation
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glm_mat4_identity(rotation_matrix);
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return TRUE;
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}
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// Create the shader program
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GLuint create_shader_program ()
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{
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GLuint vertex_shader = glCreateShader(GL_VERTEX_SHADER);
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glShaderSource(vertex_shader, 1, &vertex_shader_src, NULL);
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glCompileShader(vertex_shader);
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GLuint fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
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glShaderSource(fragment_shader, 1, &fragment_shader_src, NULL);
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glCompileShader(fragment_shader);
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GLuint program = glCreateProgram();
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glAttachShader(program, vertex_shader);
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glAttachShader(program, fragment_shader);
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glLinkProgram(program);
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glDeleteShader(vertex_shader);
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glDeleteShader(fragment_shader);
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return program;
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}
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// Setup OpenGL buffers (VBO, VAO, EBO for cubes and edges)
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void setup_buffers ()
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{
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glGenVertexArrays(1, &vao);
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glBindVertexArray(vao);
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// Vertex buffer
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glGenBuffers(1, &vbo);
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glBindBuffer(GL_ARRAY_BUFFER, vbo);
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glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
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// Face Index buffer (EBO for cube faces)
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glGenBuffers(1, &ebo);
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glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
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glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
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// Vertex attributes
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glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
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glEnableVertexAttribArray(0);
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// Edge Index buffer (EBO for cube edges)
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glGenBuffers(1, &edge_ebo);
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glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, edge_ebo);
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glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(edge_indices), edge_indices, GL_STATIC_DRAW);
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glBindVertexArray(0);
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}
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void setup_arrow_buffers() {
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glGenVertexArrays(1, &arrow_vao);
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glBindVertexArray(arrow_vao);
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// Vertex buffer for arrows
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glGenBuffers(1, &arrow_vbo);
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glBindBuffer(GL_ARRAY_BUFFER, arrow_vbo);
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glBufferData(GL_ARRAY_BUFFER, sizeof(arrow_vertices), arrow_vertices, GL_STATIC_DRAW);
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// Index buffer for arrows
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glGenBuffers(1, &arrow_ebo);
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glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, arrow_ebo);
|
||||
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(arrow_indices), arrow_indices, GL_STATIC_DRAW);
|
||||
|
||||
// Vertex attributes
|
||||
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
|
||||
glEnableVertexAttribArray(0);
|
||||
|
||||
glBindVertexArray(0);
|
||||
}
|
||||
|
||||
// Setup instance data for cubes (random positions)
|
||||
void setup_instance_data ()
|
||||
{
|
||||
g_message("[%s] setting up cube instance data...",
|
||||
__func__);
|
||||
|
||||
srand(time(NULL));
|
||||
|
||||
g_message("[%s] random seed initialized",
|
||||
__func__);
|
||||
|
||||
glGenBuffers(1, &instance_vbo);
|
||||
glBindBuffer(GL_ARRAY_BUFFER, instance_vbo);
|
||||
|
||||
g_message("[%s] instance_vbo buffer bound",
|
||||
__func__);
|
||||
|
||||
for (unsigned int i = 0; i < num_instances; i++) {
|
||||
glm_mat4_identity(instance_matrices[i]);
|
||||
|
||||
// Randomize positions
|
||||
vec3 position = {
|
||||
(float)(rand() % N_SPACE_SIZE) - 10.0f, // Random x from -10 to 10
|
||||
(float)(rand() % N_SPACE_SIZE) - 10.0f, // Random y from -10 to 10
|
||||
(float)(rand() % N_SPACE_SIZE) - 10.0f // Random z from -10 to 10
|
||||
};
|
||||
|
||||
glm_translate(instance_matrices[i], position);
|
||||
}
|
||||
g_message("[%s] generated %d cube instances",
|
||||
__func__,
|
||||
num_instances);
|
||||
|
||||
// Pass the instance matrices to the instance VBO
|
||||
glBufferData(GL_ARRAY_BUFFER, num_instances * sizeof(mat4), instance_matrices, GL_STATIC_DRAW);
|
||||
|
||||
g_message("[%s] instance matrices passed to VBO",
|
||||
__func__);
|
||||
|
||||
// Setup vertex attribute for the model matrix (location = 2)
|
||||
// Setup vertex attribute for the model matrix (location = 2)
|
||||
glBindVertexArray(vao);
|
||||
for (int i = 0; i < 4; i++) {
|
||||
glVertexAttribPointer(2 + i, 4, GL_FLOAT, GL_FALSE, sizeof(mat4), (void*)(sizeof(vec4) * i));
|
||||
glEnableVertexAttribArray(2 + i);
|
||||
glVertexAttribDivisor(2 + i, 1); // Tell OpenGL this is per-instance data
|
||||
}
|
||||
glBindVertexArray(0);
|
||||
|
||||
|
||||
g_message("[%s] finalized model matrix vertex attribute ",
|
||||
__func__);
|
||||
}
|
||||
|
||||
void setup_arrow_instance_data() {
|
||||
// Define indices for the arrows (lines from center to cube faces)
|
||||
GLuint arrow_indices[] = {
|
||||
0, 1, // Arrow pointing to right face
|
||||
0, 2, // Arrow pointing upwards
|
||||
0, 3, // Arrow pointing to front face
|
||||
0, 4, // Arrow pointing to left face
|
||||
0, 5, // Arrow pointing downwards
|
||||
0, 6 // Arrow pointing to back face
|
||||
};
|
||||
|
||||
// Generate Vertex Array Object for arrows
|
||||
glGenVertexArrays(1, &arrow_vao);
|
||||
glBindVertexArray(arrow_vao);
|
||||
|
||||
// Generate Vertex Buffer Object for arrows
|
||||
GLuint arrow_vbo;
|
||||
glGenBuffers(1, &arrow_vbo);
|
||||
glBindBuffer(GL_ARRAY_BUFFER, arrow_vbo);
|
||||
glBufferData(GL_ARRAY_BUFFER, sizeof(arrow_vertices), arrow_vertices, GL_STATIC_DRAW);
|
||||
|
||||
// Generate Element Buffer Object for arrows
|
||||
GLuint arrow_ebo;
|
||||
glGenBuffers(1, &arrow_ebo);
|
||||
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, arrow_ebo);
|
||||
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(arrow_indices), arrow_indices, GL_STATIC_DRAW);
|
||||
|
||||
// Define arrow vertex attributes
|
||||
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
|
||||
glEnableVertexAttribArray(0);
|
||||
|
||||
// Arrow instance matrices (positions) -- same as cubes
|
||||
glGenBuffers(1, &arrow_instance_vbo);
|
||||
glBindBuffer(GL_ARRAY_BUFFER, arrow_instance_vbo);
|
||||
glBufferData(GL_ARRAY_BUFFER, num_instances * sizeof(mat4), instance_matrices, GL_STATIC_DRAW);
|
||||
|
||||
// Define vertex attribute for arrow instance matrix
|
||||
for (int i = 0; i < 4; i++) {
|
||||
glVertexAttribPointer(2 + i, 4, GL_FLOAT, GL_FALSE, sizeof(mat4), (void*)(sizeof(vec4) * i));
|
||||
glEnableVertexAttribArray(2 + i);
|
||||
glVertexAttribDivisor(2 + i, 1); // Make this per-instance data
|
||||
}
|
||||
|
||||
glBindVertexArray(0);
|
||||
}
|
||||
|
||||
// Main Function
|
||||
int main (int argc, char *argv[])
|
||||
{
|
||||
GtkApplication *app;
|
||||
int status;
|
||||
|
||||
g_message("[%s] welcome in this experiment with OpenGL 4.6 in GTK4",
|
||||
__func__);
|
||||
|
||||
// Create a new GtkApplication
|
||||
app = gtk_application_new("org.example.instanced_cubes", G_APPLICATION_DEFAULT_FLAGS);
|
||||
|
||||
g_message("[%s] application created",
|
||||
__func__);
|
||||
// Connect the "activate" signal to the activate callback
|
||||
g_signal_connect(app, "activate", G_CALLBACK(on_activate), NULL);
|
||||
|
||||
g_message("[%s] activate callback linked",
|
||||
__func__);
|
||||
|
||||
// Run the application
|
||||
status = g_application_run(G_APPLICATION(app), argc, argv);
|
||||
|
||||
g_message("[%s] application terminated",
|
||||
__func__);
|
||||
|
||||
// Free the application object
|
||||
g_object_unref(app);
|
||||
|
||||
g_message("[%s] bye!",
|
||||
__func__);
|
||||
|
||||
return status;
|
||||
}
|
||||
Loading…
Reference in New Issue