Started to create GL boilerplate

glboilerplate/glboilerplate.c

@@ -0,0 +1,162 @@
+
+#include <SDL2/SDL.h>
+#include <GL/gl.h>
+#include <GL/glu.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+int main(void) {
+
+  /*
+   * RETURN CODES
+   *  0: Success
+   *  1: SDL init fail
+   *  2: Error creating Window
+   *  3: Error creating renderer
+   *
+   */
+  
+  /* ----------------
+   *  SDL Init
+   * ----------------
+   */
+  if (SDL_Init(SDL_INIT_EVERYTHING)!=0) {
+    perror("[FAILED] Initialising SDL: ");
+    return 1;
+  }
+
+  int go; //Var for loop control
+  
+  /* ----------------
+   *  Main Window
+   * ----------------
+   * Create the main output Window for SDL
+   */
+
+  // Window vars
+  int winPosX = 100; int winPosY = 100;
+  int winWidth = 640; int winHeight = 480;
+
+  Uint32 timer; // Animation timer (ms)
+
+  SDL_Window *window1 = SDL_CreateWindow(
+    "Main Window",
+    winPosX, winPosY,
+    winWidth, winHeight,
+    SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_OPENGL
+  );
+  if (window1==NULL) {
+    fprintf(stderr, "[FAILED] Creating Window window1");
+    return 2; //Error creating Window
+  }
+
+  /*
+   * ----------------
+   *  Renderer
+   * ----------------
+   * Creates the main renderer (tied to main window)
+   */
+
+  // SDL_Renderer * renderer1 = SDL_CreateRenderer(window1, -1, 0);
+  // if (renderer1==NULL) {
+  //   fprintf(stderr, "[FAILED] Creating renderer renderer1 for window1");
+  //   return 3;
+  // }
+  
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 1); // Specifies the version of the OpenGL context
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 5); // (here, 1.5) -- hello, 2003!
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_COMPATIBILITY); // Allows deprecated functions to be used
+  SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 16); // Set depth buffer to 16 bits, if OpenGL agrees (see below)
+  SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1); // Enable double buffering
+
+  SDL_GLContext context1 = SDL_GL_CreateContext(window1); // Use SDL_GL_MakeCurrent function to switch contexts
+  
+  if (context1==NULL) {
+    fprintf(stderr, "[FAILED] Creating render context context1 for window1");
+    return 3;
+  }
+
+  glFrontFace(GL_CCW); // Counter-clockwise winding
+  glEnable(GL_NORMALIZE); // Vectors normalized after transforming to keep units consistent for lighting
+  glShadeModel(GL_SMOOTH); // GL_FLAT for flat shading instead
+  glEnable(GL_DEPTH_TEST); // Enables depth comparisons
+  
+  glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+
+  glMatrixMode(GL_PROJECTION); // Sets our matrix mode (initially) to work with the projection stack
+  glLoadIdentity(); // Projection matrix is now the identity matrix, so we can work in 2D space
+  
+  gluOrtho2D(
+    -1.0*(GLdouble)(winWidth/2),  // Left
+    (GLdouble)(winWidth/2),       // Right
+    -1.0*(GLdouble)(winHeight/2), // Bottom
+    (GLdouble)(winHeight/2)       // Top
+  );
+
+  //gluOrthof(
+  //  -1.0*(GLfloat)(winWidth/2),
+  //  (GLfloat)(winWidth/2),
+  //  -1.0*(GLfloat)(winHeight/2),
+  //  (GLfloat)(winHeight/2),
+  //  (GLfloat)(-1),
+  //  (GLfloat)(1)
+  //); // Set up 2D orthographic projection matrix, so now we're officially in 2D
+
+  glViewport(0,0,winWidth,winHeight); // Set the viewport to fill the window
+
+  timer=SDL_GetTicks(); // Initialise the timer
+
+  go=1;
+  while(go) {
+
+    /*
+     * ----------------
+     *  Event handling
+     * ----------------
+     */
+    SDL_Event incomingEvent;
+    while (SDL_PollEvent(&incomingEvent)) {
+      switch (incomingEvent.type) {
+        case SDL_QUIT:
+          // User requested program quit - e.g. window close
+          go=0;
+          break;
+      }
+    }
+
+    /*
+     * ----------------
+     *  Timing
+     * ----------------
+     */
+    double timerf; { // Change scope for 'old' var
+      Uint32 old=timer;
+      timer = SDL_GetTicks();
+      timerf = (double)(timer-old)/1000.0; //0.0166... = 60FPS (1/timerf);
+    }
+
+    /*
+     * ----------------
+     *  Draw to buffer
+     * ----------------
+     */
+    
+    /*
+     * --------------------------------
+     *  Output to Window
+     * --------------------------------
+     */
+     SDL_GL_SwapWindow(window1);
+  }
+ 
+  /*
+   * --------------------------------
+   *  Clean up after ourselves
+   * --------------------------------
+   */
+   SDL_GL_DeleteContext(context1);
+   SDL_DestroyWindow(window1);
+   SDL_Quit();
+
+  return 0;
+}

glboilerplate/makefile

@@ -14,3 +14,10 @@ pongymod: $(pongymod_s)
 	clang $(pongymod_s) -l SDL2 -l GLU -l GL -o $(pongymod_c)
 	chmod +x $(pongymod_c)
 	./$(pongymod_c)
+
+glboilerplate_s = glboilerplate.c
+glboilerplate_c = glboilerplate
+glboilerplate: $(glboilerplate_s)
+	clang $(glboilerplate_s) -l SDL2 -l GLU -l GL -o $(glboilerplate_c)
+	chmod +x $(glboilerplate_c)
+	./$(glboilerplate_c)

glboilerplate/readme.md

@@ -18,3 +18,4 @@ Completed pongy.c file (collisions, paddle movement and scoring system)
 
 ## sdlboilerplate.c 
 
+> Compile using `make sdlboilerplate`