src/video/cybergfx/SDL_cgxgl.c

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* StormMesa implementation of SDL OpenGL support */

#include "SDL_cgxgl_c.h"
#include "SDL_cgxvideo.h"

#if SDL_VIDEO_OPENGL
AmigaMesaContext glcont = NULL;
#endif

/* Init OpenGL */
int
CGX_GL_Init(_THIS)
{
#if SDL_VIDEO_OPENGL
    int i = 0;
    struct TagItem attributes[14];      /* 14 should be more than enough :) */
    struct Window *win = (struct Window *) SDL_Window;

    // default config. Always used...
    attributes[i].ti_Tag = AMA_Window;
    attributes[i++].ti_Data = (unsigned long) win;
    attributes[i].ti_Tag = AMA_Left;
    attributes[i++].ti_Data = 0;
    attributes[i].ti_Tag = AMA_Bottom;
    attributes[i++].ti_Data = 0;
    attributes[i].ti_Tag = AMA_Width;
    attributes[i++].ti_Data = win->Width - win->BorderLeft - win->BorderRight;
    attributes[i].ti_Tag = AMA_Height;
    attributes[i++].ti_Data =
        win->Height - win->BorderBottom - win->BorderTop;
    attributes[i].ti_Tag = AMA_DirectRender;
    attributes[i++].ti_Data = GL_TRUE;

    // double buffer ?
    attributes[i].ti_Tag = AMA_DoubleBuf;
    if (this->gl_config.double_buffer) {
        attributes[i++].ti_Data = GL_TRUE;
    } else {
        attributes[i++].ti_Data = GL_FALSE;
    }
    // RGB(A) Mode ?
    attributes[i].ti_Tag = AMA_RGBMode;
    if (this->gl_config.red_size != 0 &&
        this->gl_config.blue_size != 0 && this->gl_config.green_size != 0) {
        attributes[i++].ti_Data = GL_TRUE;
    } else {
        attributes[i++].ti_Data = GL_FALSE;
    }
    // no depth buffer ?
    if (this->gl_config.depth_size == 0) {
        attributes[i].ti_Tag = AMA_NoDepth;
        attributes[i++].ti_Data = GL_TRUE;
    }
    // no stencil buffer ?
    if (this->gl_config.stencil_size == 0) {
        attributes[i].ti_Tag = AMA_NoStencil;
        attributes[i++].ti_Data = GL_TRUE;
    }
    // no accum buffer ?
    if (this->gl_config.accum_red_size != 0 &&
        this->gl_config.accum_blue_size != 0 &&
        this->gl_config.accum_green_size != 0) {
        attributes[i].ti_Tag = AMA_NoAccum;
        attributes[i++].ti_Data = GL_TRUE;
    }
    // done...
    attributes[i].ti_Tag = TAG_DONE;

    glcont = AmigaMesaCreateContext(attributes);
    if (glcont == NULL) {
        SDL_SetError("Couldn't create OpenGL context");
        return (-1);
    }
    this->gl_data->gl_active = 1;
    this->gl_config.driver_loaded = 1;

    return (0);
#else
    SDL_SetError("OpenGL support not configured");
    return (-1);
#endif
}

/* Quit OpenGL */
void
CGX_GL_Quit(_THIS)
{
#if SDL_VIDEO_OPENGL
    if (glcont != NULL) {
        AmigaMesaDestroyContext(glcont);
        glcont = NULL;
        this->gl_data->gl_active = 0;
        this->gl_config.driver_loaded = 0;
    }
#endif
}

/* Attach context to another window */
int
CGX_GL_Update(_THIS)
{
#if SDL_VIDEO_OPENGL
    struct TagItem tags[2];
    struct Window *win = (struct Window *) SDL_Window;
    if (glcont == NULL) {
        return -1;              //should never happen
    }
    tags[0].ti_Tag = AMA_Window;
    tags[0].ti_Data = (unsigned long) win;
    tags[1].ti_Tag = TAG_DONE;
    AmigaMesaSetRast(glcont, tags);

    return 0;
#else
    SDL_SetError("OpenGL support not configured");
    return -1;
#endif
}

#if SDL_VIDEO_OPENGL

/* Make the current context active */
int
CGX_GL_MakeCurrent(_THIS)
{
    if (glcont == NULL)
        return -1;

    AmigaMesaMakeCurrent(glcont, glcont->buffer);
    return 0;
}

void
CGX_GL_SwapBuffers(_THIS)
{
    AmigaMesaSwapBuffers(glcont);
}

int
CGX_GL_GetAttribute(_THIS, SDL_GLattr attrib, int *value)
{
    GLenum mesa_attrib;

    switch (attrib) {
    case SDL_GL_RED_SIZE:
        mesa_attrib = GL_RED_BITS;
        break;
    case SDL_GL_GREEN_SIZE:
        mesa_attrib = GL_GREEN_BITS;
        break;
    case SDL_GL_BLUE_SIZE:
        mesa_attrib = GL_BLUE_BITS;
        break;
    case SDL_GL_ALPHA_SIZE:
        mesa_attrib = GL_ALPHA_BITS;
        break;
    case SDL_GL_DOUBLEBUFFER:
        mesa_attrib = GL_DOUBLEBUFFER;
        break;
    case SDL_GL_DEPTH_SIZE:
        mesa_attrib = GL_DEPTH_BITS;
        break;
    case SDL_GL_STENCIL_SIZE:
        mesa_attrib = GL_STENCIL_BITS;
        break;
    case SDL_GL_ACCUM_RED_SIZE:
        mesa_attrib = GL_ACCUM_RED_BITS;
        break;
    case SDL_GL_ACCUM_GREEN_SIZE:
        mesa_attrib = GL_ACCUM_GREEN_BITS;
        break;
    case SDL_GL_ACCUM_BLUE_SIZE:
        mesa_attrib = GL_ACCUM_BLUE_BITS;
        break;
    case SDL_GL_ACCUM_ALPHA_SIZE:
        mesa_attrib = GL_ACCUM_ALPHA_BITS;
        break;
    default:
        return -1;
    }

    AmigaMesaGetConfig(glcont->visual, mesa_attrib, value);
    return 0;
}

void *
CGX_GL_GetProcAddress(_THIS, const char *proc)
{
    void *func = NULL;
    func = AmiGetGLProc(proc);
    return func;
}

int
CGX_GL_LoadLibrary(_THIS, const char *path)
{
    /* Library is always open */
    this->gl_config.driver_loaded = 1;

    return 0;
}

#endif /* SDL_VIDEO_OPENGL */
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