a

assignment-2a/.clang-format

@@ -1,2 +1,4 @@
 ---
 BasedOnStyle: LLVM
+
+AlignAfterOpenBracket: BlockIndent

assignment-2a/src/HW2a.cpp

@@ -12,6 +12,7 @@
 #include <istream>
 #include <optional>
 #include <sstream>
+#include <string>
 
 // Unfortunately this must be included first because it does some annoying check
 // that vomits if GLFW has already been included (dumb)
@@ -19,25 +20,41 @@
 
 #include "GLFW/glfw3.h"
 
-#define DEBUG_ON                                                               \
+// repetitive of the debug flag in the shader loading code, included here
-  0 // repetitive of the debug flag in the shader loading code, included here
 // for clarity only
+#define DEBUG_ON 1
 
 // This file contains the code that reads the shaders from their files and
 // compiles them
 #include "ShaderStuff.hpp"
 
+using namespace std;
+
 //----------------------------------------------------------------------------
 // Forward-declaring some functions for later implementation
 
+/// Print the matrix
+void printMatrix(string name, GLfloat *matrix);
+
+/// Transpose a matrix
+void transposeMatrix(GLfloat *matrix);
+
+/// Zero-initialize a GLfloat array
+void zeroInitGlfloats(GLfloat *arr, uint32_t len);
+
 /// Multiplies two matrices and puts them into result.
 ///
 /// - Left matrix must be ROW-order
 /// - Right matrix must be COLUMN-order
 ///
-/// Result will be row-order
+/// Result will be column-order
-void slow4x4MatrixMultiplyIntoRowOrder(GLfloat *left, GLfloat *right,
+void slow4x4MatrixMultiplyIntoColumnOrder(
-                                       GLfloat *result);
+    GLfloat *left, GLfloat *right, GLfloat *result
+);
+
+void slow4x4MatrixMultiplyAllRowOrder(
+    GLfloat *left, GLfloat *right, GLfloat *result
+);
 
 //----------------------------------------------------------------------------
 
@@ -50,7 +67,8 @@ typedef struct {
   GLfloat r, g, b;
 } ColorType3D;
 
-GLfloat M[16]; // general transformation matrix
+// general transformation matrix
+GLfloat M[16];
 
 // define some assorted global variables, to make life easier
 GLint m_location;
@@ -60,8 +78,11 @@ GLint window_height = 500;
 GLdouble pi = 4.0 * atan(1.0);
 
 // Added state
-GLdouble scale_x = 1.0, scale_y = 1.0;
 const GLdouble SCALE_DELTA = 0.05;
+GLdouble scale_x = 1.0, scale_y = 1.0;
+
+// Matrices
+GLfloat rotation_matrix[16], translation_matrix[16], scale_matrix[16];
 
 GLFWcursor *hand_cursor, *arrow_cursor; // some different cursors
 
@@ -76,8 +97,8 @@ static void error_callback(int error, const char *description) {
 //----------------------------------------------------------------------------
 // function that is called whenever a keyboard event occurs; defines how
 // keyboard input will be handled
-static void key_callback(GLFWwindow *window, int key, int scancode, int action,
+static void
-                         int mods) {
+key_callback(GLFWwindow *window, int key, int scancode, int action, int mods) {
   // checks to see if the escape key was pressed
   if ((key == GLFW_KEY_ESCAPE || key == GLFW_KEY_Q) && action == GLFW_PRESS)
     // closes the window
@@ -102,8 +123,8 @@ static void key_callback(GLFWwindow *window, int key, int scancode, int action,
 //----------------------------------------------------------------------------
 // function that is called whenever a mouse or trackpad button press event
 // occurs
-static void mouse_button_callback(GLFWwindow *window, int button, int action,
+static void
-                                  int mods) {
+mouse_button_callback(GLFWwindow *window, int button, int action, int mods) {
   glfwGetCursorPos(window, &mouse_x, &mouse_y);
 
   // Check which mouse button triggered the event, e.g. GLFW_MOUSE_BUTTON_LEFT,
@@ -131,6 +152,10 @@ void init(void) {
   FloatType2D vertices[NVERTICES];
   GLuint vao[1], buffer, program, location1, location2;
 
+  zeroInitGlfloats(rotation_matrix, 16);
+  zeroInitGlfloats(translation_matrix, 16);
+  zeroInitGlfloats(scale_matrix, 16);
+
   // clang-format off
   // set up some hard-coded colors and geometry
   // this part can be customized to read in an object description from a file
@@ -163,8 +188,10 @@ void init(void) {
   // position and color data
   glGenBuffers(1, &buffer);
   glBindBuffer(GL_ARRAY_BUFFER, buffer);
-  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices) + sizeof(colors), vertices,
+  glBufferData(
-               GL_STATIC_DRAW);
+      GL_ARRAY_BUFFER, sizeof(vertices) + sizeof(colors), vertices,
+      GL_STATIC_DRAW
+  );
   glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices);
   glBufferSubData(GL_ARRAY_BUFFER, sizeof(vertices), sizeof(colors), colors);
 
@@ -183,8 +210,9 @@ void init(void) {
   glVertexAttribPointer(location1, 2, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
   location2 = glGetAttribLocation(program, "vertex_color");
   glEnableVertexAttribArray(location2);
-  glVertexAttribPointer(location2, 3, GL_FLOAT, GL_FALSE, 0,
+  glVertexAttribPointer(
-                        BUFFER_OFFSET(sizeof(vertices)));
+      location2, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(sizeof(vertices))
+  );
   m_location = glGetUniformLocation(program, "M");
 
   // Define static OpenGL state variables
@@ -200,7 +228,6 @@ void init(void) {
 //----------------------------------------------------------------------------
 
 int main(int argc, char **argv) {
-
   int i;
   GLFWwindow *window;
 
@@ -237,9 +264,9 @@ int main(int argc, char **argv) {
     exit(EXIT_FAILURE);
   }
 
-  glfwSwapInterval(
+  // tells the system to wait for the rendered frame to finish updating before
-      1); // tells the system to wait for the rendered frame to finish updating
+  // swapping buffers; can help to avoid tearing
-          // before swapping buffers; can help to avoid tearing
+  glfwSwapInterval(1);
 
   // Define the keyboard callback function
   glfwSetKeyCallback(window, key_callback);
@@ -257,33 +284,40 @@ int main(int argc, char **argv) {
     // fill/re-fill the window with the background color
     glClear(GL_COLOR_BUFFER_BIT);
 
+    rotation_matrix[0] = 1.0;
+    rotation_matrix[5] = 1.0;
+    rotation_matrix[10] = 1.0;
+    rotation_matrix[15] = 1.0;
+
+    scale_matrix[0] = scale_x;
+    scale_matrix[5] = scale_y;
+    scale_matrix[10] = 1.0;
+    scale_matrix[15] = 1.0;
+
     // define/re-define the modelview matrix. In this template, we define M to
     // be the identity matrix; you will need define M according to the user's
     // actions.
-    /* for (i = 0; i < 16; i++) {
+
-      M[i] = (i % 5 == 0);
+    slow4x4MatrixMultiplyIntoColumnOrder(rotation_matrix, scale_matrix, M);
-    }*/
-    M[0] = scale_x;
-    M[5] = scale_y;
-    M[10] = 1.0;
-    M[15] = 1.0;
 
     // sanity check that your matrix contents are what you expect them to be
-    if (DEBUG_ON)
+    if (DEBUG_ON) {
-      printf("M = [%f %f %f %f\n     %f %f %f %f\n     %f %f %f %f\n     %f %f "
+      printf("--------------");
-             "%f %f]\n",
+      printf("scale_x = %f , scale_y = %f\n", scale_x, scale_y);
-             M[0], M[4], M[8], M[12], M[1], M[5], M[9], M[13], M[2], M[6],
+      printMatrix("rotation_matrix", rotation_matrix);
-             M[10], M[14], M[3], M[7], M[11], M[15]);
+      printMatrix("scale_matrix", scale_matrix);
+      printMatrix("M", M);
+    }
 
-    glUniformMatrix4fv(
+    // send the updated model transformation matrix to the GPU
-        m_location, 1, GL_FALSE,
+    glUniformMatrix4fv(m_location, 1, GL_FALSE, M);
-        M); // send the updated model transformation matrix to the GPU
+
-    glDrawArrays(
+    // draw a triangle between the first vertex and each successive vertex pair
-        GL_TRIANGLES, 0,
+    // in the hard-coded model
-        NVERTICES); // draw a triangle between the first vertex and each
+    glDrawArrays(GL_TRIANGLES, 0, NVERTICES);
-                    // successive vertex pair in the hard-coded model
+
-    glFlush(); // ensure that all OpenGL calls have executed before swapping
+    // ensure that all OpenGL calls have executed before swapping buffers
-               // buffers
+    glFlush();
 
     glfwSwapBuffers(window); // swap buffers
     glfwWaitEvents();        // wait for a new event before re-drawing
@@ -292,21 +326,57 @@ int main(int argc, char **argv) {
 
   // Clean up
   glfwDestroyWindow(window);
-  glfwTerminate(); // destroys any remaining objects, frees resources allocated
+
-                   // by GLFW
+  // destroys any remaining objects, frees resources allocated by GLFW
+  glfwTerminate();
+
   exit(EXIT_SUCCESS);
 
 } // end main
 
-void slow4x4MatrixMultiplyIntoRowOrder(GLfloat *left, GLfloat *right,
+void printMatrix(string name, GLfloat *matrix) {
-                                       GLfloat *result) {
+  printf(
+      "%s = [%f %f %f %f\n"
+      "     %f %f %f %f\n"
+      "     %f %f %f %f\n"
+      "     %f %f %f %f]\n",
+      name.c_str(), matrix[0], matrix[4], matrix[8], matrix[12], matrix[1],
+      matrix[5], matrix[9], matrix[13], matrix[2], matrix[6], matrix[10],
+      matrix[14], matrix[3], matrix[7], matrix[11], matrix[15]
+  );
+}
+
+void transposeMatrix(GLfloat *matrix) {}
+
+void zeroInitGlfloats(GLfloat *arr, uint32_t len) {
+  for (auto i = 0; i < len; ++i) {
+    arr[i] = 0.0f;
+  }
+}
+
+void slow4x4MatrixMultiplyIntoColumnOrder(
+    GLfloat *left, GLfloat *right, GLfloat *result
+) {
   for (int i = 0; i < 4; ++i) {
     for (int j = 0; j < 4; ++j) {
       for (int k = 0; k < 4; ++k) {
-        const int resultIdx = i * 4 + j;
         const GLfloat leftVal = left[i * 4 + k];
         const GLfloat rightVal = right[j * 4 + k];
-        result[i * 4 + j] += leftVal * rightVal;
+        result[j * 4 + i] += leftVal * rightVal;
+      }
+    }
+  }
+}
+
+void slow4x4MatrixMultiplyAllRowOrder(
+    GLfloat *left, GLfloat *right, GLfloat *result
+) {
+  for (int i = 0; i < 4; ++i) {
+    for (int j = 0; j < 4; ++j) {
+      for (int k = 0; k < 4; ++k) {
+        const GLfloat leftVal = left[i * 4 + k];
+        const GLfloat rightVal = right[j * 4 + k];
+        result[j * 4 + i] += leftVal * rightVal;
       }
     }
   }

assignment-2a/src/ShaderStuff.hpp

@@ -4,7 +4,7 @@
 #ifndef SHADERSTUFF
 #define SHADERSTUFF 1
 
-#define DEBUG_ON 0
+// #define DEBUG_ON 0
 #define BUFFER_OFFSET(bytes) ((GLvoid*) (bytes))
 
 // Create a NULL-terminated string by reading the provided file

assignment-2a/src/controls.cpp

@@ -1,60 +0,0 @@
-#include "controls.h"
-#include "GLFW/glfw3.h"
-#include <spdlog/spdlog.h>
-
-void key_callback(GLFWwindow *window, int key, int scancode, int action,
-                  int mods) {
-  int state = glfwGetKey(window, GLFW_KEY_E);
-
-  // checks to see if the escape or q key was pressed
-  if ((key == GLFW_KEY_ESCAPE || key == GLFW_KEY_Q) && action == GLFW_PRESS)
-    glfwSetWindowShouldClose(window, GL_TRUE);
-
-  if ((mods & GLFW_MOD_CONTROL) > 0) {
-    if (action == GLFW_PRESS) {
-      ctrl_pressed = true;
-      spdlog::debug("Press ctrl");
-    } else if (action == GLFW_RELEASE) {
-      ctrl_pressed = false;
-      spdlog::debug("Release ctrl");
-    }
-
-  } else {
-  }
-}
-
-void mouse_button_callback(GLFWwindow *window, int button, int action,
-                           int mods) {
-  glfwGetCursorPos(window, &mouse_x, &mouse_y);
-  if (button == GLFW_MOUSE_BUTTON_LEFT && action == GLFW_PRESS) {
-  }
-
-  // Pressed the left mouse button, starting drag
-  if (ctrl_pressed && button == GLFW_MOUSE_BUTTON_LEFT &&
-      action == GLFW_PRESS) {
-    is_dragging = true;
-    drag_start_x = mouse_x;
-    drag_start_y = mouse_y;
-    spdlog::debug("Start drag at ({}, {})!", drag_start_x, drag_start_y);
-  }
-
-  // Check which mouse button triggered the event, e.g. GLFW_MOUSE_BUTTON_LEFT,
-  // etc. and what the button action was, e.g. GLFW_PRESS, GLFW_RELEASE, etc.
-  // (Note that ordinary trackpad click = mouse left button)
-  // Also check if any modifier keys were active at the time of the button
-  // press, e.g. GLFW_MOD_ALT, etc. Take the appropriate action, which could
-  // (optionally) also include changing the cursor's appearance
-}
-
-void cursor_pos_callback(GLFWwindow *window, double xpos, double ypos) {
-  // determine the direction of the mouse or cursor motion
-  // update the current mouse or cursor location
-  mouse_x = xpos;
-  mouse_y = ypos;
-
-  //  (necessary to quantify the amount and direction of cursor motion)
-  // take the appropriate action
-
-  if (is_dragging) {
-  }
-}

assignment-2a/src/controls.h

@@ -1,25 +0,0 @@
-#ifndef PERIPHERALS_H_
-#define PERIPHERALS_H_
-
-#include "GLFW/glfw3.h"
-
-extern GLdouble mouse_x, mouse_y;
-extern GLfloat M[16];
-
-extern bool is_dragging, ctrl_pressed;
-extern GLdouble drag_start_x, drag_start_y;
-
-// function that is called whenever a keyboard event occurs; defines how
-// keyboard input will be handled
-void key_callback(GLFWwindow *window, int key, int scancode, int action,
-                  int mods);
-
-// function that is called whenever a mouse or trackpad button press event
-// occurs
-void mouse_button_callback(GLFWwindow *window, int button, int action,
-                           int mods);
-
-// function that is called whenever a cursor motion event occurs
-void cursor_pos_callback(GLFWwindow *window, double xpos, double ypos);
-
-#endif

assignment-2a/src/shaders.h

@@ -1,149 +0,0 @@
-#include <spdlog/spdlog.h>
-#include <string>
-
-#include <stdio.h>
-
-#include "glad/glad.h"
-
-#include "GLFW/glfw3.h"
-
-// Basic OpenGL program
-// Based on example code from: Interactive Computer Graphics: A Top-Down
-// Approach with Shader-Based OpenGL (6th Edition), by Ed Angel
-
-#ifndef SHADERSTUFF
-#define SHADERSTUFF 1
-
-#define DEBUG_ON 0
-#define BUFFER_OFFSET(bytes) ((GLvoid *)(bytes))
-
-// Create a NULL-terminated string by reading the provided file
-static char *readShaderSource(const char *shaderFile) {
-  FILE *fp;
-  long length, count;
-  char *buffer;
-  //   struct stat fileinfo;
-
-  // open the file containing the text of the shader code
-  fp = fopen(shaderFile, "rb");
-
-  // check for errors in opening the file
-  if (fp == NULL) {
-    spdlog::info(":skull: can't open shader source file {}", shaderFile);
-    return NULL;
-  }
-
-  // determine the file size
-  fseek(fp, 0, SEEK_END); // move position indicator to the end of the file;
-  length = ftell(fp);     // return the value of the current position
-  if (DEBUG_ON)
-    fprintf(stdout, "length in bytes of shader file: %ld\n", length);
-
-  // allocate a buffer with the indicated number of bytes, plus one
-  buffer = new char[length + 1];
-
-  // read the appropriate number of bytes from the file
-  fseek(fp, 0, SEEK_SET); // move position indicator to the start of the file
-  count = fread(buffer, 1, length, fp); // read all of the bytes
-  if (DEBUG_ON)
-    fprintf(stdout, "count of bytes successfully read: %ld\n", count);
-
-  // append a NULL character to indicate the end of the string
-  buffer[count] = '\0'; // because on some systems, count != length
-
-  // close the file
-  fclose(fp);
-
-  // return the string
-  return buffer;
-}
-
-// Create a GLSL program object from vertex and fragment shader files
-GLuint InitShader(const char *vShaderFileName, const char *fShaderFileName) {
-  GLuint vertex_shader, fragment_shader;
-  GLuint program;
-
-  // check GLSL version
-  if (DEBUG_ON)
-    printf("GLSL version: %s\n", glGetString(GL_SHADING_LANGUAGE_VERSION));
-
-  // Create shader handlers
-  vertex_shader = glCreateShader(GL_VERTEX_SHADER);
-  fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
-
-  // Read source code from file
-  std::string vs_text = readShaderSource(vShaderFileName);
-  std::string fs_text = readShaderSource(fShaderFileName);
-
-  // error check
-  if (vs_text == "") {
-    printf("Failed to read from vertex shader file %s\n", vShaderFileName);
-    exit(1);
-  } else if (DEBUG_ON) {
-    printf("read shader code:\n%s\n", vs_text.c_str());
-  }
-  if (fs_text == "") {
-    printf("Failed to read from fragment shader file %s\n", fShaderFileName);
-    exit(1);
-  } else if (DEBUG_ON) {
-    printf("read shader code:\n%s\n", fs_text.c_str());
-  }
-
-  // Set shader source
-  const char *vv = vs_text.c_str();
-  const char *ff = fs_text.c_str();
-  glShaderSource(vertex_shader, 1, &vv, NULL);
-  glShaderSource(fragment_shader, 1, &ff, NULL);
-
-  // Compile shaders
-  glCompileShader(vertex_shader);
-  glCompileShader(fragment_shader);
-
-  // Check for errors in compiling shaders
-  GLint compiled;
-  glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &compiled);
-  if (!compiled) {
-    printf("vertex_shader failed to compile\n");
-    if (DEBUG_ON) {
-      GLint logMaxSize, logLength;
-      glGetShaderiv(vertex_shader, GL_INFO_LOG_LENGTH, &logMaxSize);
-      printf("printing error message of %d bytes\n", logMaxSize);
-      char *logMsg = new char[logMaxSize];
-      glGetShaderInfoLog(vertex_shader, logMaxSize, &logLength, logMsg);
-      printf("%d bytes retrieved\n", logLength);
-      printf("error message: %s\n", logMsg);
-      delete[] logMsg;
-    }
-    exit(1);
-  }
-  glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &compiled);
-  if (!compiled) {
-    printf("fragment_shader failed to compile\n");
-    if (DEBUG_ON) {
-      GLint logMaxSize, logLength;
-      glGetShaderiv(fragment_shader, GL_INFO_LOG_LENGTH, &logMaxSize);
-      printf("printing error message of %d bytes\n", logMaxSize);
-      char *logMsg = new char[logMaxSize];
-      glGetShaderInfoLog(fragment_shader, logMaxSize, &logLength, logMsg);
-      printf("%d bytes retrieved\n", logLength);
-      printf("error message: %s\n", logMsg);
-      delete[] logMsg;
-    }
-    exit(1);
-  }
-
-  // Create the program
-  program = glCreateProgram();
-
-  // Attach shaders to program
-  glAttachShader(program, vertex_shader);
-  glAttachShader(program, fragment_shader);
-
-  // Link and set program to use
-  glLinkProgram(program);
-  glUseProgram(program);
-
-  return program;
-}
-
-#endif

assignment-2a/src/state.cpp

@@ -1,21 +0,0 @@
-#include "state.h"
-
-void State::populate_matrix(GLfloat *matrix) {
-  //  0  1  2  3
-  //  4  5  6  7
-  //  8  9 10 11
-  // 12 13 14 15
-
-  matrix[0] = this->x_scale;
-  matrix[5] = this->y_scale;
-  matrix[10] = 1.0;
-  matrix[15] = 1.0;
-  
-  /*
-  for (int i = 0; i < 16; i++) {
-    matrix[i] = (i % 5 == 0);
-  }
-  */
-}
-
-void State::start_dragging(pii at) { this->drag_start = at; }

assignment-2a/src/state.h

@@ -1,33 +0,0 @@
-#ifndef STATE_H_
-#define STATE_H_
-
-#include <optional>
-#include <utility>
-
-using namespace std;
-
-#include "GLFW/glfw3.h"
-
-typedef pair<int, int> pii;
-
-const double X_DELTA = 0.1, Y_DELTA = 0.1;
-
-/// The state of the program
-struct State {
-  pii mouse;
-
-  /// Where the dragging started (if it started)
-  optional<pii> drag_start;
-
-  /// Scaling factors
-  double x_scale = 1.0;
-  double y_scale = 1.0;
-
-  void populate_matrix(GLfloat *matrix);
-  void start_dragging(pii at);
-
-private:
-  GLfloat M[16];
-};
-
-#endif

assignment-2a/src/util.cpp

@@ -1,13 +0,0 @@
-#include "util.h"
-#include <spdlog/spdlog.h>
-
-optional<string> env(string ident) {
-  char *result = getenv(ident.c_str());
-  if (!result)
-    return {};
-  return string(result);
-}
-
-void error_callback(int error, const char *description) {
-  spdlog::error("{}", description);
-}

assignment-2a/src/util.h

@@ -1,12 +0,0 @@
-#ifndef UTIL_H_
-#define UTIL_H_
-
-#include <optional>
-#include <string>
-
-using namespace std;
-
-optional<string> env(string ident);
-void error_callback(int error, const char *description);
-
-#endif