Improve cube rendering in example programs

1 files changed, 80 insertions, 26 deletions

diff --git a/examples/cube_view.h b/examples/cube_view.h
index 71ae88d..bdef1f1 100644
--- a/examples/cube_view.h
+++ b/examples/cube_view.h
@@ -30,35 +30,66 @@
 
 static const float cubeStripVertices[] = {
   -1.0f,  1.0f,  1.0f, // Front top left
-  1.0f,  1.0f,  1.0f, // Front top right
+   1.0f,  1.0f,  1.0f, // Front top right
   -1.0f, -1.0f,  1.0f, // Front bottom left
-  1.0f, -1.0f,  1.0f, // Front bottom right
-  1.0f, -1.0f, -1.0f, // Back bottom right
-  1.0f,  1.0f,  1.0f, // Front top right
-  1.0f,  1.0f, -1.0f, // Back top right
+   1.0f, -1.0f,  1.0f, // Front bottom right
+   1.0f, -1.0f, -1.0f, // Back bottom right
+   1.0f,  1.0f,  1.0f, // Front top right
+   1.0f,  1.0f, -1.0f, // Back top right
   -1.0f,  1.0f,  1.0f, // Front top left
   -1.0f,  1.0f, -1.0f, // Back top left
   -1.0f, -1.0f,  1.0f, // Front bottom left
   -1.0f, -1.0f, -1.0f, // Back bottom left
-  1.0f, -1.0f, -1.0f, // Back bottom right
+   1.0f, -1.0f, -1.0f, // Back bottom right
   -1.0f,  1.0f, -1.0f, // Back top left
-  1.0f,  1.0f, -1.0f  // Back top right
+   1.0f,  1.0f, -1.0f  // Back top right
+};
+
+static const float cubeStripColorVertices[] = {
+  0.25f, 0.75f, 0.75f, // Front top left
+  0.75f, 0.75f, 0.75f, // Front top right
+  0.25f, 0.25f, 0.75f, // Front bottom left
+  0.75f, 0.25f, 0.75f, // Front bottom right
+  0.75f, 0.25f, 0.25f, // Back bottom right
+  0.75f, 0.75f, 0.75f, // Front top right
+  0.75f, 0.75f, 0.25f, // Back top right
+  0.25f, 0.75f, 0.75f, // Front top left
+  0.25f, 0.75f, 0.25f, // Back top left
+  0.25f, 0.25f, 0.75f, // Front bottom left
+  0.25f, 0.25f, 0.25f, // Back bottom left
+  0.75f, 0.25f, 0.25f, // Back bottom right
+  0.25f, 0.75f, 0.25f, // Back top left
+  0.75f, 0.75f, 0.25f  // Back top right
 };
 
 static const float cubeFrontLineLoop[] = {
   -1.0f,  1.0f,  1.0f, // Front top left
-  1.0f,  1.0f,  1.0f, // Front top right
-  1.0f, -1.0f,  1.0f, // Front bottom right
+   1.0f,  1.0f,  1.0f, // Front top right
+   1.0f, -1.0f,  1.0f, // Front bottom right
   -1.0f, -1.0f,  1.0f, // Front bottom left
 };
 
+static const float cubeFrontLineLoopColors[] = {
+  0.25f, 0.75f, 0.75f, // Front top left
+  0.75f, 0.75f, 0.75f, // Front top right
+  0.75f, 0.25f, 0.75f, // Front bottom right
+  0.25f, 0.25f, 0.75f, // Front bottom left
+};
+
 static const float cubeBackLineLoop[] = {
   -1.0f,  1.0f, -1.0f, // Back top left
-  1.0f,  1.0f, -1.0f, // Back top right
-  1.0f, -1.0f, -1.0f, // Back bottom right
+   1.0f,  1.0f, -1.0f, // Back top right
+   1.0f, -1.0f, -1.0f, // Back bottom right
   -1.0f, -1.0f, -1.0f, // Back bottom left
 };
 
+static const float cubeBackLineLoopColors[] = {
+  0.25f, 0.75f, 0.25f, // Back top left
+  0.75f, 0.75f, 0.25f, // Back top right
+  0.75f, 0.25f, 0.25f, // Back bottom right
+  0.25f, 0.25f, 0.25f  // Back bottom left
+};
+
 static const float cubeSideLines[] = {
   -1.0f,  1.0f,  1.0f, // Front top left
   -1.0f,  1.0f, -1.0f, // Back top left
@@ -73,6 +104,20 @@ static const float cubeSideLines[] = {
   1.0f, -1.0f, -1.0f, // Back bottom right
 };
 
+static const float cubeSideLineColors[] = {
+  0.25f,  0.75f,  0.75f, // Front top left
+  0.25f,  0.75f, 0.25f, // Back top left
+
+  0.25f, 0.25f,  0.75f, // Front bottom left
+  0.25f, 0.25f, 0.25f, // Back bottom left
+
+  0.75f,  0.75f,  0.75f, // Front top right
+  0.75f,  0.75f, 0.25f, // Back top right
+
+  0.75f, 0.25f,  0.75f, // Front bottom right
+  0.75f, 0.25f, 0.25f, // Back bottom right
+};
+
 // clang-format on
 
 static inline void
@@ -80,9 +125,12 @@ reshapeCube(const float width, const float height)
 {
   const float aspect = width / height;
 
+  glEnable(GL_CULL_FACE);
+  glCullFace(GL_BACK);
+  glFrontFace(GL_CW);
+
   glEnable(GL_DEPTH_TEST);
   glDepthFunc(GL_LESS);
-  glClearColor(0.2f, 0.2f, 0.2f, 1.0f);
 
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
@@ -106,8 +154,12 @@ displayCube(PuglView* const view,
   glRotatef(xAngle, 0.0f, 1.0f, 0.0f);
   glRotatef(yAngle, 1.0f, 0.0f, 0.0f);
 
-  const float bg = entered ? 0.2f : 0.0f;
-  glClearColor(bg, bg, bg, 1.0f);
+  if (entered) {
+    glClearColor(0.13f, 0.14f, 0.14f, 1.0f);
+  } else {
+    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+  }
+
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
   if (puglHasFocus(view)) {
@@ -115,25 +167,27 @@ displayCube(PuglView* const view,
     glEnableClientState(GL_VERTEX_ARRAY);
     glEnableClientState(GL_COLOR_ARRAY);
     glVertexPointer(3, GL_FLOAT, 0, cubeStripVertices);
-    glColorPointer(3, GL_FLOAT, 0, cubeStripVertices);
+    glColorPointer(3, GL_FLOAT, 0, cubeStripColorVertices);
     glDrawArrays(GL_TRIANGLE_STRIP, 0, 14);
     glDisableClientState(GL_COLOR_ARRAY);
     glDisableClientState(GL_VERTEX_ARRAY);
 
     glColor3f(0.0f, 0.0f, 0.0f);
   } else {
-    glColor3f(1.0f, 1.0f, 1.0f);
+    // Draw cube wireframe
+    glEnableClientState(GL_VERTEX_ARRAY);
+    glEnableClientState(GL_COLOR_ARRAY);
+    glVertexPointer(3, GL_FLOAT, 0, cubeFrontLineLoop);
+    glColorPointer(3, GL_FLOAT, 0, cubeFrontLineLoopColors);
+    glDrawArrays(GL_LINE_LOOP, 0, 4);
+    glVertexPointer(3, GL_FLOAT, 0, cubeBackLineLoop);
+    glColorPointer(3, GL_FLOAT, 0, cubeBackLineLoopColors);
+    glDrawArrays(GL_LINE_LOOP, 0, 4);
+    glVertexPointer(3, GL_FLOAT, 0, cubeSideLines);
+    glColorPointer(3, GL_FLOAT, 0, cubeSideLineColors);
+    glDrawArrays(GL_LINES, 0, 8);
+    glDisableClientState(GL_VERTEX_ARRAY);
   }
-
-  // Draw cube wireframe
-  glEnableClientState(GL_VERTEX_ARRAY);
-  glVertexPointer(3, GL_FLOAT, 0, cubeFrontLineLoop);
-  glDrawArrays(GL_LINE_LOOP, 0, 4);
-  glVertexPointer(3, GL_FLOAT, 0, cubeBackLineLoop);
-  glDrawArrays(GL_LINE_LOOP, 0, 4);
-  glVertexPointer(3, GL_FLOAT, 0, cubeSideLines);
-  glDrawArrays(GL_LINES, 0, 8);
-  glDisableClientState(GL_VERTEX_ARRAY);
 }
 
 #endif // EXAMPLES_CUBE_VIEW_H