switch from glfw to sdl2

2 files changed, 103 insertions, 83 deletions

diff --git a/Makefile b/Makefile
index cb1ae8e..46cebbd 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 CFLAGS=-std=c11 -W -Wall -pedantic -O2
 APP=compute-test
-LIBS=-lglfw -lGLEW -lGL
+LIBS=-lSDL2 -lGLEW -lGL
 OBJS=main.o
 
 .PHONY=all clean test
diff --git a/main.c b/main.c
index 22266db..79a9d58 100644
--- a/main.c
+++ b/main.c
@@ -1,8 +1,9 @@
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 
 #include <GL/glew.h>
-#include <GLFW/glfw3.h>
+#include <SDL2/SDL.h>
 
 #define UNUSED(a) ((void) (a))
 
@@ -35,54 +36,6 @@ fs_src =
   "  color = vec4(0.5f + 0.5 * sin(time * 3.141), 0, 0, 1);\n"
   "}\n";
 
-static void
-error_cb(
-  const int code,
-  const char *text
-) {
-  UNUSED(code);
-  fprintf(stderr, "GLFW Error: %s\n", text);
-}
-
-static void
-key_cb(
-  GLFWwindow *win,
-  int key,
-  int code,
-  int action,
-  int mods
-) {
-  UNUSED(code);
-  UNUSED(mods);
-
-  if (action == GLFW_RELEASE && key == GLFW_KEY_ESCAPE)
-    glfwSetWindowShouldClose(win, GLFW_TRUE);
-}
-
-static void
-framebuffer_size_cb(
-  GLFWwindow *win,
-  const int width,
-  const int height
-) {
-  UNUSED(win);
-
-  fprintf(stderr, "width = %d, height = %d\n", width, height);
-  glViewport(0, 0, width, height);
-}
-
-static void drop_cb(
-  GLFWwindow *win,
-  const int num_paths,
-  const char ** paths
-) {
-  UNUSED(win);
-
-  for (int i = 0; i < num_paths; i++) {
-    fprintf(stderr, "drop path: %s\n", paths[i]);
-  }
-}
-
 static GLuint
 compile_shader(
   const GLenum type,
@@ -157,44 +110,73 @@ link_compute_program(
 }
 #endif
 
-static GLFWwindow *
+static SDL_Window *
 init(void) {
-  // init glfw
-  glfwSetErrorCallback(error_cb);
-  if (!glfwInit())
+  if (SDL_Init(SDL_INIT_VIDEO) < 0) {
+    SDL_Log("SDL_Init() failed: %s", SDL_GetError());
     exit(EXIT_FAILURE);
-
-  // set api to GLES 3.2
-  glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
-  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
+  }
 
   // create window
-  GLFWwindow *win = glfwCreateWindow(640, 480, "Compute Test", NULL, NULL);
+  SDL_Window *win = SDL_CreateWindow(
+    "Compute Test",
+    SDL_WINDOWPOS_UNDEFINED,
+    SDL_WINDOWPOS_UNDEFINED,
+    640,
+    480,
+    SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE
+  );
+
+  // check for error
   if (!win) {
+    SDL_Log("SDL_CreateWindow() failed: %s", SDL_GetError());
+    exit(EXIT_FAILURE);
+  }
+
+  // set gl context majory version hint
+  if (SDL_GL_SetAttribute(
+    SDL_GL_CONTEXT_PROFILE_MASK,
+    SDL_GL_CONTEXT_PROFILE_ES
+  ) < 0) {
+    SDL_Log("SDL_GL_SetAttribute() failed: %s", SDL_GetError());
+    exit(EXIT_FAILURE);
+  }
+
+  // set gl context majory version hint
+  if (SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3) < 0) {
+    SDL_Log("SDL_GL_SetAttribute() failed: %s", SDL_GetError());
+    exit(EXIT_FAILURE);
+  }
+
+  // set gl context minor version hint
+  if (SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2) < 0) {
+    SDL_Log("SDL_GL_SetAttribute() failed: %s", SDL_GetError());
     exit(EXIT_FAILURE);
   }
 
-  // set gl context
-  glfwMakeContextCurrent(win);
+  // create GL context
+  SDL_GLContext context = SDL_GL_CreateContext(win);
+  if (!context) {
+    SDL_Log("SDL_GL_CreateContext() failed: %s", SDL_GetError());
+    exit(EXIT_FAILURE);
+  }
 
   // init glew
   // (do this immediately after setting context)
-  GLenum err = glewInit();
-  if (err != GLEW_OK) {
-    fprintf(stderr, "GLEW Error: %s\n", glewGetErrorString(err));
-    exit(EXIT_FAILURE);
+  {
+    GLenum err = glewInit();
+    if (err != GLEW_OK) {
+      SDL_Log("glewInit() failed: %s", glewGetErrorString(err));
+      exit(EXIT_FAILURE);
+    }
   }
 
   // set swap interval
   // (after context init)
-  glfwSwapInterval(1);
-
-  // bind event handlers
-  // (after context init)
-  glfwSetKeyCallback(win, key_cb);
-  glfwSetFramebufferSizeCallback(win, framebuffer_size_cb);
-  glfwSetDropCallback(win, drop_cb);
+  if (SDL_GL_SetSwapInterval(1) < 0) {
+    SDL_Log("SDL_GL_SetSwapInterval() failed: %s", SDL_GetError());
+    exit(EXIT_FAILURE);
+  }
 
   // return window
   return win;
@@ -204,7 +186,7 @@ int main(int argc, char *argv[]) {
   UNUSED(argc);
   UNUSED(argv);
 
-  GLFWwindow *win = init();
+  SDL_Window *win = init();
 
   // generate vertex array
   GLuint vao;
@@ -228,14 +210,15 @@ int main(int argc, char *argv[]) {
   GLint u_time = glGetUniformLocation(prog, "time");
 
   // main loop
-  while (!glfwWindowShouldClose(win)) {
+  bool done = false, fullscreen = false;
+  while (!done) {
     // clear screen
     glClearColor(0, 0, 0, 1);
     glClear(GL_COLOR_BUFFER_BIT);
 
     // use program, set uniform
     glUseProgram(prog);
-    glUniform1f(u_time, glfwGetTime());
+    glUniform1f(u_time, SDL_GetTicks() / 1000.0);
 
     // draw
     glBindVertexArray(vao);
@@ -243,18 +226,55 @@ int main(int argc, char *argv[]) {
     glBindVertexArray(0);
 
     // swap buffer
-    glfwSwapBuffers(win);
+    SDL_GL_SwapWindow(win);
 
     // handle events
-    glfwPollEvents();
-    // glfwWaitEvents();
+    {
+      SDL_Event ev;
+
+      while (SDL_PollEvent(&ev)) {
+        switch (ev.type) {
+        case SDL_QUIT:
+          done = true;
+          break;
+        case SDL_KEYDOWN:
+          switch (ev.key.keysym.sym) {
+          case SDLK_ESCAPE:
+            done = true;
+
+            break;
+          case SDLK_F11:
+            // toggle fullscreen
+            fullscreen = !fullscreen;
+
+            if (SDL_SetWindowFullscreen(
+              win,
+              fullscreen ? SDL_WINDOW_FULLSCREEN_DESKTOP : 0
+            ) < 0) {
+              SDL_Log("SDL_SetWindowFullscreen() failed: %s", SDL_GetError());
+              fullscreen = !fullscreen;
+            }
+
+            break;
+          }
+
+          break;
+        case SDL_WINDOWEVENT:
+          switch (ev.window.event) {
+          case SDL_WINDOWEVENT_SIZE_CHANGED:
+            // update viewport
+            glViewport(0, 0, ev.window.data1, ev.window.data2);
+            break;
+          }
+
+          break;
+        }
+      }
+    }
   }
 
   // destroy window
-  glfwDestroyWindow(win);
-
-  // fini glfw
-  glfwTerminate();
+  SDL_DestroyWindow(win);
 
   // return success
   return EXIT_SUCCESS;