demos: require gl 2.0 headers

The GL_VERSION_X_Y defines tells us that we have an gl.h file that
supports OpenGL X.Y. Considering it's been almost two decades since
OpenGL 2.0 was released, let's just always assume that it's recent
enough.

Reviewed-by: Hoe Hao Cheng <haochengho12907@gmail.com>

3 files changed, 28 insertions, 50 deletions

diff --git a/src/demos/dinoshade.c b/src/demos/dinoshade.c
index ad0ef3de..f904813a 100644
--- a/src/demos/dinoshade.c
+++ b/src/demos/dinoshade.c
@@ -533,21 +533,17 @@ redraw(void)
 	 to raise the depth of the projected shadow slightly so
 	 that it does not depth buffer alias with the floor. */
       if (offsetShadow) {
-	switch (polygonOffsetVersion) {
-	case EXTENSION:
-#ifdef GL_EXT_polygon_offset
-	  glEnable(GL_POLYGON_OFFSET_EXT);
-	  break;
-#endif
-#ifdef GL_VERSION_1_1
-	case ONE_DOT_ONE:
-          glEnable(GL_POLYGON_OFFSET_FILL);
-	  break;
-#endif
-	case MISSING:
-	  /* Oh well. */
-	  break;
-	}
+         switch (polygonOffsetVersion) {
+         case EXTENSION:
+            glEnable(GL_POLYGON_OFFSET_EXT);
+            break;
+         case ONE_DOT_ONE:
+            glEnable(GL_POLYGON_OFFSET_FILL);
+            break;
+         case MISSING:
+            /* Oh well. */
+            break;
+         }
       }
 
       /* Render 50% black shadow color on top of whatever the
@@ -567,21 +563,17 @@ redraw(void)
       glEnable(GL_LIGHTING);
 
       if (offsetShadow) {
-	switch (polygonOffsetVersion) {
-#ifdef GL_EXT_polygon_offset
-	case EXTENSION:
-	  glDisable(GL_POLYGON_OFFSET_EXT);
-	  break;
-#endif
-#ifdef GL_VERSION_1_1
-	case ONE_DOT_ONE:
-          glDisable(GL_POLYGON_OFFSET_FILL);
-	  break;
-#endif
-	case MISSING:
-	  /* Oh well. */
-	  break;
-	}
+         switch (polygonOffsetVersion) {
+         case EXTENSION:
+            glDisable(GL_POLYGON_OFFSET_EXT);
+            break;
+         case ONE_DOT_ONE:
+            glDisable(GL_POLYGON_OFFSET_FILL);
+            break;
+         case MISSING:
+            /* Oh well. */
+            break;
+         }
       }
       if (stencilShadow) {
         glDisable(GL_STENCIL_TEST);
@@ -851,21 +843,15 @@ main(int argc, char **argv)
   glutAttachMenu(GLUT_RIGHT_BUTTON);
   makeDinosaur();
 
-#ifdef GL_VERSION_1_1
   if (GLAD_GL_VERSION_1_1 && !forceExtension) {
     polygonOffsetVersion = ONE_DOT_ONE;
     glPolygonOffset(-2.0, -9.0);
-  } else
-#endif
-  {
-#ifdef GL_EXT_polygon_offset
-  /* check for the polygon offset extension */
-  if (GLAD_GL_EXT_polygon_offset) {
-    polygonOffsetVersion = EXTENSION;
-    glPolygonOffsetEXT(-2.0, -0.002);
-  } else 
-#endif
-    {
+  } else {
+    /* check for the polygon offset extension */
+    if (GLAD_GL_EXT_polygon_offset) {
+      polygonOffsetVersion = EXTENSION;
+      glPolygonOffsetEXT(-2.0, -0.002);
+    } else {
       polygonOffsetVersion = MISSING;
       printf("\ndinoshine: Missing polygon offset.\n");
       printf("           Expect shadow depth aliasing artifacts.\n\n");
diff --git a/src/demos/glinfo.c b/src/demos/glinfo.c
index 62bf5a36..103c1d5e 100644
--- a/src/demos/glinfo.c
+++ b/src/demos/glinfo.c
@@ -25,7 +25,6 @@ int main( int argc, char *argv[] )
    printf("GL_VENDOR: %s\n", (char *) glGetString(GL_VENDOR));
    printf("GL_EXTENSIONS: %s\n", (char *) glGetString(GL_EXTENSIONS));
 
-#ifdef GL_VERSION_2_0
    {
       const GLubyte *v = glGetString(GL_VERSION);
       if (v[0] * 10 + v[2] >= 20) {
@@ -33,7 +32,6 @@ int main( int argc, char *argv[] )
          printf("GL_SHADING_LANGUAGE_VERSION = %s\n", slv);
       }
    }
-#endif
 
    printf("GLU_VERSION: %s\n", (char *) gluGetString(GLU_VERSION));
    printf("GLU_EXTENSIONS: %s\n", (char *) gluGetString(GLU_EXTENSIONS));
diff --git a/src/demos/spriteblast.c b/src/demos/spriteblast.c
index 9aeae506..9ce4966d 100644
--- a/src/demos/spriteblast.c
+++ b/src/demos/spriteblast.c
@@ -442,12 +442,8 @@ key(unsigned char c, int x, int y)
   case 'o':
   case 'O':
     org ^= 1;
-#ifdef GL_VERSION_2_0
-#ifdef GL_ARB_point_parameters
     glPointParameteri(GL_POINT_SPRITE_COORD_ORIGIN,
                       org ? GL_LOWER_LEFT : GL_UPPER_LEFT);
-#endif
-#endif
     glutPostRedisplay();
     break;
   case 't':
@@ -656,9 +652,7 @@ main(int argc, char **argv)
   glEnable(GL_POINT_SMOOTH);
   glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
   glPointSize(32.0);
-#ifdef GL_ARB_point_parameters
   glPointParameterfvARB(GL_POINT_DISTANCE_ATTENUATION_ARB, theQuad);
-#endif
 
   glutMainLoop();
   return 0;             /* ANSI C requires main to return int. */