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Diffstat (limited to 'make/glu-interface-common-CustomJavaCode.java')
-rw-r--r-- | make/glu-interface-common-CustomJavaCode.java | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/make/glu-interface-common-CustomJavaCode.java b/make/glu-interface-common-CustomJavaCode.java new file mode 100644 index 000000000..b520c9487 --- /dev/null +++ b/make/glu-interface-common-CustomJavaCode.java @@ -0,0 +1,66 @@ + +/** + * Returns true if the specified GLU core- or extension-function can be + * successfully used through this GLU instance. By "successfully" we mean + * that the function is both <i>callable</i> on the machine running the + * program and <i>available</i> on the current display.<P> + * + * A GLU function is <i>callable</i> if it is a GLU core- or extension-function + * that is supported by the underlying GLU implementation. The function is + * <i>available</i> if the OpenGL implementation on the display meets the + * requirements of the GLU function being called (because GLU functions utilize + * OpenGL functions). <P> + * + * Whether or not a GLU function is <i>callable</i> is determined as follows: + * <ul> + * <li>If the function is a GLU core function (i.e., not an + * extension), <code>gluGetString(GLU_VERSION)</code> is used to determine the + * version number of the underlying GLU implementation on the host. + * then the function name is cross-referenced with that specification to + * see if it is part of that version's specification. + * + * <li> If the function is a GLU extension, the function name is + * cross-referenced with the list returned by + * <code>gluGetString(GLU_EXTENSIONS)</code> to see if the function is one of + * the extensions that is supported by the underlying GLU implementation. + * </ul> + * + * Whether or not a GLU function is <i>available</i> is determined as follows: + * <ul> + * <li>If the function is a GLU core function then the function is first + * cross-referenced with the GLU specifications to find the minimum GLU + * version required to <i>call</i> that GLU function. Then the following table + * is consulted to determine the minimum GL version required for that version + * of GLU: + * <ul> + * <li> GLU 1.0 requires OpenGL 1.0 + * <li> GLU 1.1 requires OpenGL 1.0 + * <li> GLU 1.2 requires OpenGL 1.1 + * <li> GLU 1.3 requires OpenGL 1.2 + * </ul> + * Finally, <code>glGetString(GL_VERSION)</code> is used to determine the + * highest OpenGL version that both host and display support, and from that it + * is possible to determine if the GL facilities required by the GLU function + * are <i>available</i> on the display. + * + * <li> If the function is a GLU extension, the function name is + * cross-referenced with the list returned by + * <code>gluGetString(GLU_EXTENSIONS)</code> to see if the function is one of + * the extensions that is supported by the underlying GLU implementation. + * </ul> + * + * <b>NOTE:</b>The availability of a function may change at runtime in + * response to changes in the display environment. For example, when a window + * is dragged from one display to another on a multi-display system, or when + * the properties of the display device are modified (e.g., changing the color + * depth of the display). Any application that is concerned with handling + * these situations correctly should confirm availability after a display + * change before calling a questionable OpenGL function. To detect a change in + * the display device, please see {@link + * GLEventListener#displayChanged(GLDrawable,boolean,boolean)}. + * + * @param gluFunctionName the name of the OpenGL function (e.g., use + * "gluNurbsCallbackDataEXT" to check if the <code> + * gluNurbsCallbackDataEXT(GLUnurbs, GLvoid)</code> extension is available). + */ +public boolean isFunctionAvailable(String gluFunctionName); |