lib/glesv2: use `GLES` to cleanly organize top level services

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>

diff --git a/lib/glesv2/glesv2.nit b/lib/glesv2/glesv2.nit
index bd19380..670c903 100644 (file)
--- a/lib/glesv2/glesv2.nit
+++ b/lib/glesv2/glesv2.nit
@@ -348,59 +348,65 @@ extern class GLError
        end
 end
 
-# Clear the color buffer with `r`, `g`, `b`, `a`
-protected fun gl_clear_color(r, g, b, a: Float) `{ glClearColor(r, g, b, a); `}
-
-# Set the viewport
-protected fun gl_viewport(x, y, width, height: Int) `{ glViewport(x, y, width, height); `}
-
-# Direct call to `glClear`, call with a combinaison of `gl_clear_color_buffer`,
-# `gl_stencil_buffer_bit` and `gl_color_buffer_bit`.
-private fun gl_clear(flag: Int) `{ glClear(flag); `}
-
-protected fun gl_depth_buffer_bit: Int do return 0x0100
-protected fun gl_stencil_buffer_bit: Int do return 0x0400
-protected fun gl_color_buffer_bit: Int do return 0x4000
-
-protected fun gl_clear_color_buffer do gl_clear(gl_color_buffer_bit)
-protected fun gl_clear_depth_buffer do gl_clear(gl_depth_buffer_bit)
-protected fun gl_clear_stencil_buffer do gl_clear(gl_stencil_buffer_bit)
-
-protected fun gl_error: GLError `{ return glGetError(); `}
 protected fun assert_no_gl_error
 do
-       var error = gl_error
+       var error = gl.error
        if not error.is_ok then
                print "GL error: {error}"
                abort
        end
 end
 
-# Query the boolean value at `key`
-private fun gl_get_bool(key: Int): Bool `{
-       GLboolean val;
-       glGetBooleanv(key, &val);
-       return val == GL_TRUE;
-`}
+redef class Sys
+       private var gles = new GLES is lazy
+end
 
-# Query the floating point value at `key`
-private fun gl_get_float(key: Int): Float `{
-       GLfloat val;
-       glGetFloatv(key, &val);
-       return val;
-`}
+# Entry points to OpenGL ES 2.0 services
+fun gl: GLES do return sys.gles
 
-# Query the integer value at `key`
-private fun gl_get_int(key: Int): Int `{
-       GLint val;
-       glGetIntegerv(key, &val);
-       return val;
-`}
+# OpenGL ES 2.0 services
+class GLES
 
-# Does this driver support shader compilation?
-#
-# Should always return `true` in OpenGL ES 2.0 and 3.0.
-fun gl_shader_compiler: Bool do return gl_get_bool(0x8DFA)
+       # Clear the color buffer to `red`, `green`, `blue` and `alpha`
+       fun clear_color(red, green, blue, alpha: Float) `{
+               glClearColor(red, green, blue, alpha);
+       `}
+
+       # Set the viewport
+       fun viewport(x, y, width, height: Int) `{ glViewport(x, y, width, height); `}
+
+       # Clear the `buffer`
+       fun clear(buffer: GLBuffer) `{ glClear(buffer); `}
+
+       # Last error from OpenGL ES 2.0
+       fun error: GLError `{ return glGetError(); `}
+
+       # Query the boolean value at `key`
+       private fun get_bool(key: Int): Bool `{
+               GLboolean val;
+               glGetBooleanv(key, &val);
+               return val == GL_TRUE;
+       `}
+
+       # Query the floating point value at `key`
+       private fun get_float(key: Int): Float `{
+               GLfloat val;
+               glGetFloatv(key, &val);
+               return val;
+       `}
+
+       # Query the integer value at `key`
+       private fun get_int(key: Int): Int `{
+               GLint val;
+               glGetIntegerv(key, &val);
+               return val;
+       `}
+
+       # Does this driver support shader compilation?
+       #
+       # Should always return `true` in OpenGL ES 2.0 and 3.0.
+       fun shader_compiler: Bool do return get_bool(0x8DFA)
+end
 
 # Float related data types of OpenGL ES 2.0 shaders
 #
@@ -442,3 +448,23 @@ extern class GLDataType
        fun is_sampler_2d: Bool `{ return recv == GL_SAMPLER_2D; `}
        fun is_sampler_cube: Bool `{ return recv == GL_SAMPLER_CUBE; `}
 end
+
+# Set of buffers as a bitwise OR mask, used by `GLES::clear`
+#
+# ~~~
+# var buffers = (new GLBuffer).color.depth
+# gl.clear buffers
+# ~~~
+extern class GLBuffer `{ GLbitfield `}
+       # Get an empty set of buffers
+       new `{ return 0; `}
+
+       # Add the color buffer to the returned buffer set
+       fun color: GLBuffer `{ return recv | GL_COLOR_BUFFER_BIT; `}
+
+       # Add the depth buffer to the returned buffer set
+       fun depth: GLBuffer `{ return recv | GL_DEPTH_BUFFER_BIT; `}
+
+       # Add the stencil buffer to the returned buffer set
+       fun stencil: GLBuffer `{ return recv | GL_STENCIL_BUFFER_BIT; `}
+end