Create a class for Renderable objects

src/client/client_imgui.cpp

@@ -15,6 +15,8 @@
 
 #include "common/shaderloader.hpp"
 
+#include "renderable.hpp"
+
 // Globals
 static Logger logger;
 static MessageBus messager(&logger);
@@ -79,22 +81,15 @@ int main(int argc, char** argv)
     int height = 0, width = 0;
     ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
     float fov = 45.0;
-    // Triangle example
+
-    // @see http://www.opengl-tutorial.org/beginners-tutorials/tutorial-2-the-first-triangle/
+    // Required before OpenGL Calls.
-    GLuint VertexArrayID;
+    GLuint vertex_array;
-    glGenVertexArrays(1, &VertexArrayID);
+    glGenVertexArrays(1, &vertex_array);
-    glBindVertexArray(VertexArrayID);
+    glBindVertexArray(vertex_array);
-    GLuint vertexbuffer;
+
-    // An array of 3 vectors which represents 3 vertices
+    Renderable::Object triangle = Renderable::Object(Renderable::triangle_data, sizeof(Renderable::triangle_data));
-    static const GLfloat g_vertex_buffer_data[] = {
+    Renderable::Object cube = Renderable::Object(Renderable::cube_data, sizeof(Renderable::cube_data), Renderable::cube_color, sizeof(Renderable::cube_color));
-       -1.0f, -1.0f, 0.0f,
+    cube.set_position(glm::vec3(0.f, 0.f, -5.f));
-       1.0f, -1.0f, 0.0f,
-       0.0f,  1.0f, 0.0f,
-    };
-    glGenBuffers(1, &vertexbuffer);
-    glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data),
-                 g_vertex_buffer_data, GL_STATIC_DRAW);
     static Console console(&messager);
     bool show_console = false;
 
@@ -107,6 +102,9 @@ int main(int argc, char** argv)
     static struct ShaderRegistry shader_registry;
     loadShadersFromFile(shader_list, &shader_registry);
     static std::vector<RegisteredShaderProgram> shader_program_registry;
+    // @BUG This is a temporary hack. When shader_program_registry is grown, the existing
+    // entries lose data.
+    shader_program_registry.reserve(10);
     loadShaderProgramsFromFile("shaders/shader_programs.txt", &shader_registry, &shader_program_registry);
     messager.registerCallback(&debug_messagebus_callback);
     int window_height, window_width;
@@ -134,6 +132,7 @@ int main(int argc, char** argv)
        // Camera movement?
        double cv_x = 0.f;
        double cv_y = 0.f;
+       // This is "kind of" a pan, since it translates the point being looked at by the same value.
        if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS) {
           cv_x += camera_velocity * dt;
        }
@@ -151,6 +150,7 @@ int main(int argc, char** argv)
        auto ncla = glm::translate(glm::mat4(1.0f), camera_translation) * glm::vec4(camera_looking_at[0], camera_looking_at[1], camera_looking_at[2], 1.0f);
        camera_position = glm::vec3(ncp[0], ncp[1], ncp[2]);
        camera_looking_at = glm::vec3(ncla[0], ncla[1], ncla[2]);
+
        view = glm::lookAt(camera_position, camera_looking_at, glm::vec3(0,1,0));
 
        // Process messages
@@ -170,27 +170,15 @@ int main(int argc, char** argv)
        glfwGetWindowSize(window, &window_width, &window_height);
        projection = glm::perspective(glm::radians(fov), (float) window_width / (float) window_height,
                                      0.1f, 100.0f);
-       mvp_matrix = projection * view * model_default;
+       glm::mat4 vp = projection * view;
        // @see https://blog.conan.io/2019/06/26/An-introduction-to-the-Dear-ImGui-library.html
        // 1st attribute buffer : vertices
        GLuint p = find_shader_program_by_name("default", &shader_program_registry);
-       glUseProgram(p);
+       triangle.render(vp, p);
-       GLuint matrix_id = glGetUniformLocation(p, "MVP");
+
-       glUniformMatrix4fv(matrix_id, 1, GL_FALSE, &mvp_matrix[0][0]);
+       // Draw a cube?
-       glEnableVertexAttribArray(0);
+       p = find_shader_program_by_name("color", &shader_program_registry);
-       glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
+       cube.render(vp, p);
-       glVertexAttribPointer(
-          0,                  // attribute 0. No particular reason for 0, but must match the layout in the shader.
-          3,                  // size
-          GL_FLOAT,           // type
-          GL_FALSE,           // normalized?
-          0,                  // stride
-          (void*)0            // array buffer offset
-          );
-       // Draw the triangle !
-       glDrawArrays(GL_TRIANGLES, 0, 3); // Starting from vertex 0; 3 vertices total -> 1 triangle
-       glDisableVertexAttribArray(0);
-       glUseProgram(0);
 
        // Start the Dear ImGui frame
        ImGui_ImplOpenGL3_NewFrame();

src/client/renderable.hpp

@@ -0,0 +1,180 @@
+#ifndef _RENDERABLE_H_
+#define _RENDERABLE_H_
+
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <glm/gtc/matrix_transform.hpp>
+
+namespace Renderable {
+   class Object {
+   public:
+      Object(const GLfloat * vertex_data, int vd_size, const GLfloat * color_data = 0, int cd_size = 0) {
+         this->vertex_buffer_data = (GLfloat *) vertex_data;
+         this->vertex_buffer_data_size = vd_size;
+         this->colour_buffer_data = (GLfloat *) color_data;
+         this->colour_buffer_data_size = cd_size;
+         this->init();
+      }
+      void init() {
+         if (this->vertex_buffer != 0) {
+            // @TODO: Delete OpenGL buffer
+         }
+         if (this->vertex_buffer_data != 0) {
+            glGenBuffers(1, &this->vertex_buffer);
+            glBindBuffer(GL_ARRAY_BUFFER, this->vertex_buffer);
+            glBufferData(GL_ARRAY_BUFFER, this->vertex_buffer_data_size,
+                         this->vertex_buffer_data, GL_STATIC_DRAW);
+            printf("Vertex_buffer: %d (%d, %d)\n", this->vertex_buffer, this->vertex_buffer_data_size,
+                   this->vertex_buffer_data_size / sizeof(GLfloat) / 3);
+         }
+         if (this->colour_buffer != 0) {
+            // @TODO: Delete OpenGL buffer
+         }
+         if (this->colour_buffer_data != 0) {
+            glGenBuffers(1, &this->colour_buffer);
+            glBindBuffer(GL_ARRAY_BUFFER, this->colour_buffer);
+            glBufferData(GL_ARRAY_BUFFER, sizeof(this->colour_buffer_data),
+                         this->colour_buffer_data, GL_STATIC_DRAW);
+         }
+      }
+      void render(glm::mat4 vp, GLuint shader_program = 0) {
+         if (this->vertex_buffer == 0) {
+            return;
+         }
+         glUseProgram(shader_program);
+         glm::mat4 mvp = vp * this->get_model_matrix();
+         GLuint matrix_id = glGetUniformLocation(shader_program, "MVP");
+         glUniformMatrix4fv(matrix_id, 1, GL_FALSE, &mvp[0][0]);
+         glEnableVertexAttribArray(0);
+         glBindBuffer(GL_ARRAY_BUFFER, this->vertex_buffer);
+         glVertexAttribPointer(
+            0,                  // attribute 0. No particular reason for 0, but must match the layout in the shader.
+            3,                  // size
+            GL_FLOAT,           // type
+            GL_FALSE,           // normalized?
+            0,                  // stride
+            (void*)0            // array buffer offset
+            );
+         glDrawArrays(GL_TRIANGLES, 0, this->vertex_buffer_data_size / sizeof(GLfloat) / 3); // Starting from vertex 0; 3 vertices total -> 1 triangle
+         if (this->colour_buffer == 0) {
+            glDisableVertexAttribArray(0);
+            glUseProgram(0);
+            return;
+         }
+         glEnableVertexAttribArray(1);
+         glBindBuffer(GL_ARRAY_BUFFER, this->colour_buffer);
+         glVertexAttribPointer(
+            1,                                // attribute. No particular reason for 1, but must match the layout in the shader.
+            3,                                // size
+            GL_FLOAT,                         // type
+            GL_FALSE,                         // normalized?
+            0,                                // stride
+            (void*)0                          // array buffer offset
+            );
+         glDisableVertexAttribArray(0);
+         glDisableVertexAttribArray(1);
+         glUseProgram(0);
+      }
+      void set_position(glm::vec3 position) {
+         this->translation = glm::translate(glm::mat4(1.f), position);
+      }
+   private:
+      glm::mat4 get_model_matrix() {
+         return translation * rotation * scale;
+      }
+      GLuint vertex_buffer = 0;
+      GLuint colour_buffer = 0;
+      GLfloat *colour_buffer_data = 0;
+      int colour_buffer_data_size = 0;
+      GLfloat *vertex_buffer_data = 0;
+      int vertex_buffer_data_size = 0;
+      glm::mat4 translation = glm::mat4(1.f);
+      glm::mat4 scale = glm::mat4(1.f);
+      glm::mat4 rotation = glm::mat4(1.f);
+   };
+
+   static const GLfloat cube_data[] = {
+      -1.0f,-1.0f,-1.0f, // triangle 1 : begin
+      -1.0f,-1.0f, 1.0f,
+      -1.0f, 1.0f, 1.0f, // triangle 1 : end
+      1.0f, 1.0f,-1.0f, // triangle 2 : begin
+      -1.0f,-1.0f,-1.0f,
+      -1.0f, 1.0f,-1.0f, // triangle 2 : end
+      1.0f,-1.0f, 1.0f,
+      -1.0f,-1.0f,-1.0f,
+      1.0f,-1.0f,-1.0f,
+      1.0f, 1.0f,-1.0f,
+      1.0f,-1.0f,-1.0f,
+      -1.0f,-1.0f,-1.0f,
+      -1.0f,-1.0f,-1.0f,
+      -1.0f, 1.0f, 1.0f,
+      -1.0f, 1.0f,-1.0f,
+      1.0f,-1.0f, 1.0f,
+      -1.0f,-1.0f, 1.0f,
+      -1.0f,-1.0f,-1.0f,
+      -1.0f, 1.0f, 1.0f,
+      -1.0f,-1.0f, 1.0f,
+      1.0f,-1.0f, 1.0f,
+      1.0f, 1.0f, 1.0f,
+      1.0f,-1.0f,-1.0f,
+      1.0f, 1.0f,-1.0f,
+      1.0f,-1.0f,-1.0f,
+      1.0f, 1.0f, 1.0f,
+      1.0f,-1.0f, 1.0f,
+      1.0f, 1.0f, 1.0f,
+      1.0f, 1.0f,-1.0f,
+      -1.0f, 1.0f,-1.0f,
+      1.0f, 1.0f, 1.0f,
+      -1.0f, 1.0f,-1.0f,
+      -1.0f, 1.0f, 1.0f,
+      1.0f, 1.0f, 1.0f,
+      -1.0f, 1.0f, 1.0f,
+      1.0f,-1.0f, 1.0f
+   };
+   static const GLfloat cube_color[] = {
+      -1.0f,-1.0f,-1.0f, // triangle 1 : begin
+      -1.0f,-1.0f, 1.0f,
+      -1.0f, 1.0f, 1.0f, // triangle 1 : end
+      1.0f, 1.0f,-1.0f, // triangle 2 : begin
+      -1.0f,-1.0f,-1.0f,
+      -1.0f, 1.0f,-1.0f, // triangle 2 : end
+      1.0f,-1.0f, 1.0f,
+      -1.0f,-1.0f,-1.0f,
+      1.0f,-1.0f,-1.0f,
+      1.0f, 1.0f,-1.0f,
+      1.0f,-1.0f,-1.0f,
+      -1.0f,-1.0f,-1.0f,
+      -1.0f,-1.0f,-1.0f,
+      -1.0f, 1.0f, 1.0f,
+      -1.0f, 1.0f,-1.0f,
+      1.0f,-1.0f, 1.0f,
+      -1.0f,-1.0f, 1.0f,
+      -1.0f,-1.0f,-1.0f,
+      -1.0f, 1.0f, 1.0f,
+      -1.0f,-1.0f, 1.0f,
+      1.0f,-1.0f, 1.0f,
+      1.0f, 1.0f, 1.0f,
+      1.0f,-1.0f,-1.0f,
+      1.0f, 1.0f,-1.0f,
+      1.0f,-1.0f,-1.0f,
+      1.0f, 1.0f, 1.0f,
+      1.0f,-1.0f, 1.0f,
+      1.0f, 1.0f, 1.0f,
+      1.0f, 1.0f,-1.0f,
+      -1.0f, 1.0f,-1.0f,
+      1.0f, 1.0f, 1.0f,
+      -1.0f, 1.0f,-1.0f,
+      -1.0f, 1.0f, 1.0f,
+      1.0f, 1.0f, 1.0f,
+      -1.0f, 1.0f, 1.0f,
+      1.0f,-1.0f, 1.0f
+   };
+
+   static const GLfloat triangle_data[] = {
+       -1.0f, -1.0f, 0.0f,
+       1.0f, -1.0f, 0.0f,
+       0.0f,  1.0f, 0.0f,
+    };
+}
+
+#endif // _RENDERABLE_H_

src/common/shaderloader.hpp

@@ -203,7 +203,7 @@ int loadShaderProgramsFromFile(const char* file_path, struct ShaderRegistry *sha
          // Skipping, line is a comment
          continue;
       }
-      char *line_copy = (char*) calloc(size, sizeof(char*));
+      char *line_copy = (char*) calloc(size + 1, sizeof(char*));
       strncpy(line_copy, line, size);
       printf("%s\n", line_copy);
 
@@ -277,6 +277,7 @@ int loadShadersFromFile(const char* file_path, struct ShaderRegistry *registry)
    char *line;
    size_t size = 0;
    const char *delim = ",";
+   printf("Loading shaders listed in '%s'\n", file_path);
    fp = fopen(file_path, "r");
    if (fp == NULL) {
       return -1;
@@ -296,7 +297,7 @@ int loadShadersFromFile(const char* file_path, struct ShaderRegistry *registry)
          // Skipping, line is a comment
          continue;
       }
-      char *line_copy = (char*) malloc((size) * sizeof(char*));
+      char *line_copy = (char*) malloc((size+1) * sizeof(char*));
       strncpy(line_copy, line, size);
       // Format <name>,<type>,<filepath>
       name = strtok(line_copy, delim);

src/shaders/colorVertexShader.glsl

@@ -0,0 +1,11 @@
+#version 300 es
+layout(location = 0) in vec3 vertexPosition_modelspace;
+layout(location = 1) in vec3 vertexColor;
+uniform mat4 MVP;
+out mediump vec3 fragmentColor;
+void main(){
+  gl_Position.xyz = vertexPosition_modelspace;
+  gl_Position.w = 1.0;
+  gl_Position = MVP * gl_Position;
+  fragmentColor = vertexColor;
+}

src/shaders/fragmentColour.glsl

@@ -0,0 +1,7 @@
+#version 300 es
+// the precision mediump is required in 3.0es
+in mediump vec3 fragmentColor;
+out mediump vec3 color;
+void main(){
+  color = fragmentColor;
+}

src/shaders/shader_list.txt

@@ -7,4 +7,6 @@
 # or compute.
 #
 defaultVertexShader,vertex,defaultVertexShader.glsl
+colorVertexShader,vertex,colorVertexShader.glsl
 fragmentRed,fragment,fragmentRed.glsl
+fragmentColour,fragment,fragmentColour.glsl

src/shaders/shader_programs.txt

@@ -3,3 +3,4 @@
 # Each line is a program. <program_name>:<shader1>,<shader2>,...<shaderN>
 #
 default:defaultVertexShader,fragmentRed
+color:colorVertexShader,fragmentColour