Improve query documentation, document type of all query targets.

src/Magnum/AbstractQuery.h

@@ -136,11 +136,10 @@ class MAGNUM_EXPORT AbstractQuery: public AbstractObject {
          * See @ref resultAvailable().
          * @see @fn_gl{GetQueryObject} with @def_gl{QUERY_RESULT}
          * @requires_gl33 Extension @extension{ARB,timer_query} for result
-         *      type @ref Magnum::UnsignedInt "UnsignedInt" and @ref Magnum::Long
-         *      "Long"
+         *      type @ref Magnum::UnsignedLong "UnsignedLong" and @ref Magnum::Long "Long"
          * @requires_es_extension Extension @es_extension{EXT,disjoint_timer_query}
          *      for result types @ref Magnum::Int "Int", @ref Magnum::UnsignedLong "UnsignedLong"
-         *      @ref Magnum::Long "Long".
+         *      and @ref Magnum::Long "Long".
          * @requires_gles Only @ref Magnum::UnsignedInt "UnsignedInt" result
          *      type is available in WebGL.
          */

src/Magnum/PrimitiveQuery.h

@@ -73,7 +73,8 @@ class PrimitiveQuery: public AbstractQuery {
             #ifndef MAGNUM_TARGET_GLES2
             /**
              * Count of primitives generated from vertex shader or geometry
-             * shader.
+             * shader. Use @ref result<UnsignedInt>() or @ref result<Int>() to
+             * retrieve the result.
              * @requires_gles30 Not defined in OpenGL ES 2.0.
              * @requires_es_extension Extension @es_extension{ANDROID,extension_pack_es31a}/
              *      @es_extension{EXT,geometry_shader}
@@ -86,7 +87,11 @@ class PrimitiveQuery: public AbstractQuery {
             #endif
             #endif
 
-            /** Count of primitives written to transform feedback buffer. */
+            /**
+             * Count of primitives written to transform feedback buffer. Use
+             * @ref result<UnsignedInt>() or @ref result<Int>() to retrieve the
+             * result.
+             */
             TransformFeedbackPrimitivesWritten = GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN
         };
 

src/Magnum/SampleQuery.h

@@ -86,7 +86,9 @@ class SampleQuery: public AbstractQuery {
         enum class Target: GLenum {
             #ifndef MAGNUM_TARGET_GLES
             /**
-             * Count of samples passed from fragment shader
+             * Count of samples passed from fragment shader. Use
+             * @ref result<UnsignedInt>() or @ref result<Int>() to retrieve the
+             * result.
              * @requires_gl Only boolean query is available in OpenGL ES and
              *      WebGL.
              */
@@ -94,7 +96,8 @@ class SampleQuery: public AbstractQuery {
             #endif
 
             /**
-             * Whether any samples passed from fragment shader
+             * Whether any samples passed from fragment shader. Use
+             * @ref result<bool>() to retrieve the result.
              * @requires_gl33 Extension @extension{ARB,occlusion_query2}
              */
             #ifndef MAGNUM_TARGET_GLES2
@@ -104,10 +107,10 @@ class SampleQuery: public AbstractQuery {
             #endif
 
             /**
-             * Whether any samples passed from fragment shader (conservative)
-             *
-             * An implementation may choose a less precise version of the
-             * test at the expense of some false positives.
+             * Whether any samples passed from fragment shader (conservative).
+             * An implementation may choose a less precise version of the test
+             * at the expense of some false positives. Use @ref result<bool>()
+             * to retrieve the result.
              * @requires_gl43 Extension @extension{ARB,ES3_compatibility}
              */
             #ifndef MAGNUM_TARGET_GLES2

src/Magnum/TimeQuery.h

@@ -81,14 +81,22 @@ class TimeQuery: public AbstractQuery {
     public:
         /** @brief Query target */
         enum class Target: GLenum {
-            /** Elapsed time */
+            /**
+             * Elapsed time. Use @ref result<UnsignedLong>() or @ref result<Long>()
+             * to retrieve the result.
+             * @see @ref timestamp()
+             */
             #ifndef MAGNUM_TARGET_GLES
             TimeElapsed = GL_TIME_ELAPSED,
             #else
             TimeElapsed = GL_TIME_ELAPSED_EXT,
             #endif
 
-            /** Timestamp (for use with @ref timestamp() only) */
+            /**
+             * Timestamp. For use with @ref timestamp() only, use
+             * @ref result<UnsignedLong>() or @ref result<Long>() to retrieve
+             * the result.
+             */
             #ifndef MAGNUM_TARGET_GLES
             Timestamp = GL_TIMESTAMP
             #else
@@ -144,6 +152,8 @@ class TimeQuery: public AbstractQuery {
         /**
          * @brief Query timestamp
          *
+         * Use @ref result<UnsignedLong>() or @ref result<Long>() to retrieve
+         * the result.
          * @see @fn_gl{QueryCounter} with @def_gl{TIMESTAMP}
          */
         void timestamp() {