cleanup example

examples/glfw_hello_world.cpp

@@ -10,6 +10,9 @@
 // System
 #include <iostream>
 
+#define WINDOW_WIDTH 1024
+#define WINDOW_HEIGHT 768
+
 int main(int argc, char **argv) {
     // Initialise GLFW
     if (!glfwInit()) {
@@ -29,18 +32,18 @@ int main(int argc, char **argv) {
     // Open a window and create its OpenGL context
     GLFWwindow *window; // (In the accompanying source code, this variable is
                         // global for simplicity)
-    window = glfwCreateWindow(1024, 768, "MonkVG Hello World", NULL, NULL);
+    window = glfwCreateWindow(WINDOW_WIDTH, WINDOW_HEIGHT, "MonkVG Hello World",
+                              NULL, NULL);
     if (window == NULL) {
-        fprintf(
-            stderr,
-            "Failed to open GLFW window.\n");
+        fprintf(stderr, "Failed to open GLFW window.\n");
         glfwTerminate();
         return -1;
     }
     glfwMakeContextCurrent(window); // Initialize GLEW
 
     // Initialize MonkVG using GLES 2.0 rendering
-    vgCreateContextMNK(1024, 768, VG_RENDERING_BACKEND_TYPE_OPENGLES20);
+    vgCreateContextMNK(WINDOW_WIDTH, WINDOW_HEIGHT,
+                       VG_RENDERING_BACKEND_TYPE_OPENGLES20);
 
     // create a paint
     VGPaint paint;
@@ -52,26 +55,37 @@ int main(int argc, char **argv) {
 
     // create a simple box path
     VGPath path;
-    path = vgCreatePath(VG_PATH_FORMAT_STANDARD, VG_PATH_DATATYPE_F, 1, 0, 0,
-                         0, VG_PATH_CAPABILITY_ALL);
-    vguRect(path, 150.0f, 150.0f, 190.0f, 150.0f);
+    path = vgCreatePath(VG_PATH_FORMAT_STANDARD, VG_PATH_DATATYPE_F, 1, 0, 0, 0,
+                        VG_PATH_CAPABILITY_ALL);
+    vguRect(path, 0.0f, 0.0f, 100.0f, 150.0f);
 
     // Ensure we can capture the escape key being pressed below
     glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);
 
+    // set viewport
+    int width, height;
+    glfwGetFramebufferSize(window, &width, &height);
+    glViewport(0, 0, width, height);
+
     do {
 
         // Clear the screen.
         glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
+        /// do an ortho camera
+        // NOTE:  this is not standard OpenVG
+        vgPushOrthoCamera(0.0f, (float)width, (float)height, 0.0f, -1.0f, 1.0f);
+
         /// draw the basic path
         vgSeti(VG_MATRIX_MODE, VG_MATRIX_PATH_USER_TO_SURFACE);
         vgLoadIdentity();
-        vgTranslate(1024 / 2, 768 / 2);
+        vgTranslate(width / 2, height / 2);
         vgSetPaint(paint, VG_FILL_PATH);
         vgDrawPath(path, VG_FILL_PATH);
 
+        vgPopOrthoCamera();
+
         // Swap buffers
         glfwSwapBuffers(window);
         glfwPollEvents();
@@ -80,5 +94,12 @@ int main(int argc, char **argv) {
     while (glfwGetKey(window, GLFW_KEY_ESCAPE) != GLFW_PRESS &&
            glfwWindowShouldClose(window) == 0);
 
+    // destroy MonkVG
+    vgDestroyPath(path);
+    vgDestroyPaint(paint);
+    vgDestroyContextMNK();
+
+    glfwDestroyWindow(window);
+
     return 0;
 }