osmesa.c

mesa-6.5-minigui源码

                                               accumBits,
                                               accumBits,
                                               alphaBits ? accumBits : 0,
                                               1            /* num samples */
                                               );
      if (!osmesa->gl_visual) {
         FREE(osmesa);
         return NULL;
      }

      /* Initialize device driver function table */
      _mesa_init_driver_functions(&functions);
      /* override with our functions */
      functions.GetString = get_string;
      functions.UpdateState = osmesa_update_state;
      functions.GetBufferSize = get_buffer_size;

      if (!_mesa_initialize_context(&osmesa->mesa,
                                    osmesa->gl_visual,
                                    sharelist ? &sharelist->mesa
                                              : (GLcontext *) NULL,
                                    &functions, (void *) osmesa)) {
         _mesa_destroy_visual( osmesa->gl_visual );
         FREE(osmesa);
         return NULL;
      }

      _mesa_enable_sw_extensions(&(osmesa->mesa));
      _mesa_enable_1_3_extensions(&(osmesa->mesa));
      _mesa_enable_1_4_extensions(&(osmesa->mesa));
      _mesa_enable_1_5_extensions(&(osmesa->mesa));

      osmesa->gl_buffer = _mesa_create_framebuffer(osmesa->gl_visual);
      if (!osmesa->gl_buffer) {
         _mesa_destroy_visual( osmesa->gl_visual );
         _mesa_free_context_data( &osmesa->mesa );
         FREE(osmesa);
         return NULL;
      }

      /* create front color buffer in user-provided memory (no back buffer) */
      _mesa_add_renderbuffer(osmesa->gl_buffer, BUFFER_FRONT_LEFT,
                             new_osmesa_renderbuffer(format));
      _mesa_add_soft_renderbuffers(osmesa->gl_buffer,
                                   GL_FALSE, /* color */
                                   osmesa->gl_visual->haveDepthBuffer,
                                   osmesa->gl_visual->haveStencilBuffer,
                                   osmesa->gl_visual->haveAccumBuffer,
                                   GL_FALSE, /* alpha */
                                   GL_FALSE /* aux */ );

      osmesa->format = format;
      osmesa->buffer = NULL;
      osmesa->width = 0;
      osmesa->height = 0;
      osmesa->userRowLength = 0;
      osmesa->rowlength = 0;
      osmesa->yup = GL_TRUE;
      osmesa->rInd = rind;
      osmesa->gInd = gind;
      osmesa->bInd = bind;
      osmesa->aInd = aind;

      /* Initialize the software rasterizer and helper modules. */
      {
	 GLcontext *ctx = &osmesa->mesa;
         SWcontext *swrast;
         TNLcontext *tnl;

	 if (!_swrast_CreateContext( ctx ) ||
             !_ac_CreateContext( ctx ) ||
             !_tnl_CreateContext( ctx ) ||
             !_swsetup_CreateContext( ctx )) {
            _mesa_destroy_visual(osmesa->gl_visual);
            _mesa_free_context_data(ctx);
            _mesa_free(osmesa);
            return NULL;
         }
	
	 _swsetup_Wakeup( ctx );

         /* use default TCL pipeline */
         tnl = TNL_CONTEXT(ctx);
         tnl->Driver.RunPipeline = _tnl_run_pipeline;

         /* Extend the software rasterizer with our optimized line and triangle
          * drawing functions.
          */
         swrast = SWRAST_CONTEXT( ctx );
         swrast->choose_line = osmesa_choose_line;
         swrast->choose_triangle = osmesa_choose_triangle;
      }
   }
   return osmesa;
}


/*
 * Destroy an Off-Screen Mesa rendering context.
 *
 * Input:  ctx - the context to destroy
 */
GLAPI void GLAPIENTRY
OSMesaDestroyContext( OSMesaContext ctx )
{
   if (ctx) {
      _swsetup_DestroyContext( &ctx->mesa );
      _tnl_DestroyContext( &ctx->mesa );
      _ac_DestroyContext( &ctx->mesa );
      _swrast_DestroyContext( &ctx->mesa );

      _mesa_destroy_visual( ctx->gl_visual );
      _mesa_destroy_framebuffer( ctx->gl_buffer );
      _mesa_free_context_data( &ctx->mesa );
      FREE( ctx );
   }
}


/*
 * Recompute the values of the context's rowaddr array.
 */
static void
compute_row_addresses( OSMesaContext ctx )
{
   GLint bytesPerPixel, bytesPerRow, i;
   GLubyte *origin = (GLubyte *) ctx->buffer;

   if (ctx->format == OSMESA_COLOR_INDEX) {
      /* CI mode */
      bytesPerPixel = 1 * sizeof(GLubyte);
   }
   else if ((ctx->format == OSMESA_RGB) || (ctx->format == OSMESA_BGR)) {
      /* RGB mode */
      bytesPerPixel = 3 * sizeof(GLchan);
   }
   else if (ctx->format == OSMESA_RGB_565) {
      /* 5/6/5 RGB pixel in 16 bits */
      bytesPerPixel = 2;
   }
   else {
      /* RGBA mode */
      bytesPerPixel = 4 * sizeof(GLchan);
   }

   bytesPerRow = ctx->rowlength * bytesPerPixel;

   if (ctx->yup) {
      /* Y=0 is bottom line of window */
      for (i = 0; i < MAX_HEIGHT; i++) {
         ctx->rowaddr[i] = (GLchan *) ((GLubyte *) origin + i * bytesPerRow);
      }
   }
   else {
      /* Y=0 is top line of window */
      for (i = 0; i < MAX_HEIGHT; i++) {
         GLint j = ctx->height - i - 1;
         ctx->rowaddr[i] = (GLchan *) ((GLubyte *) origin + j * bytesPerRow);
      }
   }
}


/*
 * Bind an OSMesaContext to an image buffer.  The image buffer is just a
 * block of memory which the client provides.  Its size must be at least
 * as large as width*height*sizeof(type).  Its address should be a multiple
 * of 4 if using RGBA mode.
 *
 * Image data is stored in the order of glDrawPixels:  row-major order
 * with the lower-left image pixel stored in the first array position
 * (ie. bottom-to-top).
 *
 * If the context's viewport hasn't been initialized yet, it will now be
 * initialized to (0,0,width,height).
 *
 * Input:  ctx - the rendering context
 *         buffer - the image buffer memory
 *         type - data type for pixel components
 *            Normally, only GL_UNSIGNED_BYTE and GL_UNSIGNED_SHORT_5_6_5
 *            are supported.  But if Mesa's been compiled with CHAN_BITS==16
 *            then type must be GL_UNSIGNED_SHORT.  And if Mesa's been build
 *            with CHAN_BITS==32 then type must be GL_FLOAT.
 *         width, height - size of image buffer in pixels, at least 1
 * Return:  GL_TRUE if success, GL_FALSE if error because of invalid ctx,
 *          invalid buffer address, invalid type, width<1, height<1,
 *          width>internal limit or height>internal limit.
 */
GLAPI GLboolean GLAPIENTRY
OSMesaMakeCurrent( OSMesaContext ctx, void *buffer, GLenum type,
                   GLsizei width, GLsizei height )
{
   if (!ctx || !buffer ||
       width < 1 || height < 1 ||
       width > MAX_WIDTH || height > MAX_HEIGHT) {
      return GL_FALSE;
   }

   if (ctx->format == OSMESA_RGB_565) {
      if (type != GL_UNSIGNED_SHORT_5_6_5)
         return GL_FALSE;
   }
   else if (type != CHAN_TYPE) {
      return GL_FALSE;
   }

   /* Need to set these before calling _mesa_make_current() since the first
    * time the context is bound, _mesa_make_current() will call our
    * get_buffer_size() function to initialize the viewport.  These are the
    * values returned by get_buffer_size():
    */
   ctx->buffer = buffer;
   ctx->width = width;
   ctx->height = height;

   osmesa_update_state( &ctx->mesa, 0 );

   /* Call this periodically to detect when the user has begun using
    * GL rendering from multiple threads.
    */
   _glapi_check_multithread();

   _mesa_make_current( &ctx->mesa, ctx->gl_buffer, ctx->gl_buffer );

   if (ctx->userRowLength)
      ctx->rowlength = ctx->userRowLength;
   else
      ctx->rowlength = width;

   compute_row_addresses( ctx );

   /* this will make ensure we recognize the new buffer size */
   _mesa_resize_framebuffer(&ctx->mesa, ctx->gl_buffer, width, height);

   return GL_TRUE;
}



GLAPI OSMesaContext GLAPIENTRY
OSMesaGetCurrentContext( void )
{
   GLcontext *ctx = _mesa_get_current_context();
   if (ctx)
      return (OSMesaContext) ctx;
   else
      return NULL;
}



GLAPI void GLAPIENTRY
OSMesaPixelStore( GLint pname, GLint value )
{
   OSMesaContext osmesa = OSMesaGetCurrentContext();

   switch (pname) {
      case OSMESA_ROW_LENGTH:
         if (value<0) {
            _mesa_error( &osmesa->mesa, GL_INVALID_VALUE,
                      "OSMesaPixelStore(value)" );
            return;
         }
         osmesa->userRowLength = value;
         osmesa->rowlength = value ? value : osmesa->width;
         break;
      case OSMESA_Y_UP:
         osmesa->yup = value ? GL_TRUE : GL_FALSE;
         break;
      default:
         _mesa_error( &osmesa->mesa, GL_INVALID_ENUM, "OSMesaPixelStore(pname)" );
         return;
   }

   compute_row_addresses( osmesa );
}


GLAPI void GLAPIENTRY
OSMesaGetIntegerv( GLint pname, GLint *value )
{
   OSMesaContext osmesa = OSMesaGetCurrentContext();

   switch (pname) {
      case OSMESA_WIDTH:
         *value = osmesa->width;
         return;
      case OSMESA_HEIGHT:
         *value = osmesa->height;
         return;
      case OSMESA_FORMAT:
         *value = osmesa->format;
         return;
      case OSMESA_TYPE:
         *value = CHAN_TYPE;
         return;
      case OSMESA_ROW_LENGTH:
         *value = osmesa->userRowLength;
         return;
      case OSMESA_Y_UP:
         *value = osmesa->yup;
         return;
      case OSMESA_MAX_WIDTH:
         *value = MAX_WIDTH;
         return;
      case OSMESA_MAX_HEIGHT:
         *value = MAX_HEIGHT;
         return;
      default:
         _mesa_error(&osmesa->mesa, GL_INVALID_ENUM, "OSMesaGetIntergerv(pname)");
         return;
   }
}

/*
 * Return the depth buffer associated with an OSMesa context.
 * Input:  c - the OSMesa context
 * Output:  width, height - size of buffer in pixels
 *          bytesPerValue - bytes per depth value (2 or 4)
 *          buffer - pointer to depth buffer values
 * Return:  GL_TRUE or GL_FALSE to indicate success or failure.
 */
GLAPI GLboolean GLAPIENTRY
OSMesaGetDepthBuffer( OSMesaContext c, GLint *width, GLint *height,
                      GLint *bytesPerValue, void **buffer )
{
   struct gl_renderbuffer *rb = NULL;

   if (c->gl_buffer)
      rb = c->gl_buffer->Attachment[BUFFER_DEPTH].Renderbuffer;

   if (!rb || !rb->Data) {
      /*if ((!c->gl_buffer) || (!c->gl_buffer->DepthBuffer)) {*/
      *width = 0;
      *height = 0;
      *bytesPerValue = 0;
      *buffer = 0;
      return GL_FALSE;
   }
   else {
      *width = c->gl_buffer->Width;
      *height = c->gl_buffer->Height;
      if (c->gl_visual->depthBits <= 16)
         *bytesPerValue = sizeof(GLushort);
      else
         *bytesPerValue = sizeof(GLuint);
      *buffer = rb->Data;
      return GL_TRUE;
   }
}

/*
 * Return the color buffer associated with an OSMesa context.
 * Input:  c - the OSMesa context
 * Output:  width, height - size of buffer in pixels
 *          format - the pixel format (OSMESA_FORMAT)
 *          buffer - pointer to color buffer values
 * Return:  GL_TRUE or GL_FALSE to indicate success or failure.
 */
GLAPI GLboolean GLAPIENTRY
OSMesaGetColorBuffer( OSMesaContext c, GLint *width,
                      GLint *height, GLint *format, void **buffer )
{
   if (!c->buffer) {
      *width = 0;
      *height = 0;
      *format = 0;
      *buffer = 0;
      return GL_FALSE;
   }
   else {
      *width = c->width;
      *height = c->height;
      *format = c->format;
      *buffer = c->buffer;
      return GL_TRUE;
   }
}


struct name_function
{
   const char *Name;
   OSMESAproc Function;
};

static struct name_function functions[] = {
   { "OSMesaCreateContext", (OSMESAproc) OSMesaCreateContext },
   { "OSMesaCreateContextExt", (OSMESAproc) OSMesaCreateContextExt },
   { "OSMesaDestroyContext", (OSMESAproc) OSMesaDestroyContext },
   { "OSMesaMakeCurrent", (OSMESAproc) OSMesaMakeCurrent },
   { "OSMesaGetCurrentContext", (OSMESAproc) OSMesaGetCurrentContext },
   { "OSMesaPixelsStore", (OSMESAproc) OSMesaPixelStore },
   { "OSMesaGetIntegerv", (OSMESAproc) OSMesaGetIntegerv },
   { "OSMesaGetDepthBuffer", (OSMESAproc) OSMesaGetDepthBuffer },
   { "OSMesaGetColorBuffer", (OSMESAproc) OSMesaGetColorBuffer },
   { "OSMesaGetProcAddress", (OSMESAproc) OSMesaGetProcAddress },
   { NULL, NULL }
};


GLAPI OSMESAproc GLAPIENTRY
OSMesaGetProcAddress( const char *funcName )
{
   int i;
   for (i = 0; functions[i].Name; i++) {
      if (_mesa_strcmp(functions[i].Name, funcName) == 0)
         return functions[i].Function;
   }
   return _glapi_get_proc_address(funcName);
}


GLAPI void GLAPIENTRY
OSMesaColorClamp(GLboolean enable)
{
   OSMesaContext osmesa = OSMesaGetCurrentContext();

   if (enable == GL_TRUE) {
      osmesa->mesa.Color.ClampFragmentColor = GL_TRUE;
   }
   else {
      osmesa->mesa.Color.ClampFragmentColor = GL_FIXED_ONLY_ARB;
   }
}