opengl/libs/GLES2/gl2.cpp

/* 
 ** Copyright 2007, The Android Open Source Project
 **
 ** Licensed under the Apache License, Version 2.0 (the "License"); 
 ** you may not use this file except in compliance with the License. 
 ** You may obtain a copy of the License at 
 **
 **     http://www.apache.org/licenses/LICENSE-2.0 
 **
 ** Unless required by applicable law or agreed to in writing, software 
 ** distributed under the License is distributed on an "AS IS" BASIS, 
 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 ** See the License for the specific language governing permissions and 
 ** limitations under the License.
 */

#include <ctype.h>
#include <string.h>
#include <errno.h>

#include <sys/ioctl.h>

#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>

#include <cutils/log.h>
#include <cutils/properties.h>

#include "hooks.h"
#include "egl_impl.h"

using namespace android;

// ----------------------------------------------------------------------------
// Actual GL entry-points
// ----------------------------------------------------------------------------

#undef API_ENTRY
#undef CALL_GL_API
#undef CALL_GL_API_RETURN

#if USE_FAST_TLS_KEY

    #ifdef HAVE_ARM_TLS_REGISTER
        #define GET_TLS(reg) \
            "mrc p15, 0, " #reg ", c13, c0, 3 \n"
    #else
        #define GET_TLS(reg) \
            "mov   " #reg ", #0xFFFF0FFF      \n"  \
            "ldr   " #reg ", [" #reg ", #-15] \n"
    #endif

    #define API_ENTRY(_api) __attribute__((naked)) _api

    #define CALL_GL_API(_api, ...)                              \
         asm volatile(                                          \
            GET_TLS(r12)                                        \
            "ldr   r12, [r12, %[tls]] \n"                       \
            "cmp   r12, #0            \n"                       \
            "ldrne pc,  [r12, %[api]] \n"                       \
            "mov   r0, #0             \n"                       \
            "bx    lr                 \n"                       \
            :                                                   \
            : [tls] "J"(TLS_SLOT_OPENGL_API*4),                 \
              [api] "J"(__builtin_offsetof(gl_hooks_t, gl._api))    \
            :                                                   \
            );

    #define CALL_GL_API_RETURN(_api, ...) \
        CALL_GL_API(_api, __VA_ARGS__) \
        return 0; // placate gcc's warnings. never reached.

#else

    #define API_ENTRY(_api) _api

    #define CALL_GL_API(_api, ...)                                       \
        gl_hooks_t::gl_t const * const _c = &getGlThreadSpecific()->gl;  \
        _c->_api(__VA_ARGS__);

    #define CALL_GL_API_RETURN(_api, ...)                                \
        gl_hooks_t::gl_t const * const _c = &getGlThreadSpecific()->gl;  \
        return _c->_api(__VA_ARGS__)

#endif


extern "C" {
#include "gl2_api.in"
#include "gl2ext_api.in"
}

#undef API_ENTRY
#undef CALL_GL_API
#undef CALL_GL_API_RETURN

/*
 * glGetString() is special because we expose some extensions in the wrapper
 */

extern "C" const GLubyte * __glGetString(GLenum name);

const GLubyte * glGetString(GLenum name)
{
    const GLubyte * ret = egl_get_string_for_current_context(name);
    if (ret == NULL) {
        ret = __glGetString(name);
    }
    return ret;
}