src/mesa/swrast/s_renderbuffer.c - platform/external/mesa3d - Git at Google

 /*
  * Mesa 3-D graphics library
  * Version:  6.5
  *
  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included
  * in all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */


 /**
  * Functions for allocating/managing software-based renderbuffers.
  * Also, routines for reading/writing software-based renderbuffer data as
  * ubytes, ushorts, uints, etc.
  */


 #include "main/glheader.h"
 #include "main/imports.h"
 #include "main/context.h"
 #include "main/fbobject.h"
 #include "main/formats.h"
 #include "main/mtypes.h"
 #include "main/renderbuffer.h"
 #include "swrast/s_context.h"
 #include "swrast/s_renderbuffer.h"


 /**
  * This is a software fallback for the gl_renderbuffer->AllocStorage
  * function.
  * Device drivers will typically override this function for the buffers
  * which it manages (typically color buffers, Z and stencil).
  * Other buffers (like software accumulation and aux buffers) which the driver
  * doesn't manage can be handled with this function.
  *
  * This one multi-purpose function can allocate stencil, depth, accum, color
  * or color-index buffers!
  */
 static GLboolean
 soft_renderbuffer_storage(struct gl_context *ctx, struct gl_renderbuffer *rb,
                           GLenum internalFormat,
                           GLuint width, GLuint height)
 {
    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
    GLuint bpp;

    switch (internalFormat) {
    case GL_RGB:
    case GL_R3_G3_B2:
    case GL_RGB4:
    case GL_RGB5:
    case GL_RGB8:
    case GL_RGB10:
    case GL_RGB12:
    case GL_RGB16:
       rb->Format = MESA_FORMAT_RGB888;
       break;
    case GL_RGBA:
    case GL_RGBA2:
    case GL_RGBA4:
    case GL_RGB5_A1:
    case GL_RGBA8:
 #if 1
    case GL_RGB10_A2:
    case GL_RGBA12:
 #endif
       if (_mesa_little_endian())
          rb->Format = MESA_FORMAT_RGBA8888_REV;
       else
          rb->Format = MESA_FORMAT_RGBA8888;
       break;
    case GL_RGBA16:
    case GL_RGBA16_SNORM:
       /* for accum buffer */
       rb->Format = MESA_FORMAT_SIGNED_RGBA_16;
       break;
    case GL_STENCIL_INDEX:
    case GL_STENCIL_INDEX1_EXT:
    case GL_STENCIL_INDEX4_EXT:
    case GL_STENCIL_INDEX8_EXT:
    case GL_STENCIL_INDEX16_EXT:
       rb->Format = MESA_FORMAT_S8;
       break;
    case GL_DEPTH_COMPONENT:
    case GL_DEPTH_COMPONENT16:
       rb->Format = MESA_FORMAT_Z16;
       break;
    case GL_DEPTH_COMPONENT24:
       rb->Format = MESA_FORMAT_X8_Z24;
       break;
    case GL_DEPTH_COMPONENT32:
       rb->Format = MESA_FORMAT_Z32;
       break;
    case GL_DEPTH_STENCIL_EXT:
    case GL_DEPTH24_STENCIL8_EXT:
       rb->Format = MESA_FORMAT_Z24_S8;
       break;
    default:
       /* unsupported format */
       return GL_FALSE;
    }

    bpp = _mesa_get_format_bytes(rb->Format);

    /* free old buffer storage */
    if (srb->Buffer) {
       free(srb->Buffer);
       srb->Buffer = NULL;
    }

    srb->RowStride = width * bpp;

    if (width > 0 && height > 0) {
       /* allocate new buffer storage */
       srb->Buffer = malloc(srb->RowStride * height);

       if (srb->Buffer == NULL) {
          rb->Width = 0;
          rb->Height = 0;
          _mesa_error(ctx, GL_OUT_OF_MEMORY,
                      "software renderbuffer allocation (%d x %d x %d)",
                      width, height, bpp);
          return GL_FALSE;
       }
    }

    rb->Width = width;
    rb->Height = height;
    rb->_BaseFormat = _mesa_base_fbo_format(ctx, internalFormat);

    if (rb->Name == 0 &&
        internalFormat == GL_RGBA16_SNORM &&
        rb->_BaseFormat == 0) {
       /* NOTE: This is a special case just for accumulation buffers.
        * This is a very limited use case- there's no snorm texturing or
        * rendering going on.
        */
       rb->_BaseFormat = GL_RGBA;
    }
    else {
       /* the internalFormat should have been error checked long ago */
       ASSERT(rb->_BaseFormat);
    }

    return GL_TRUE;
 }


 /**
  * Called via gl_renderbuffer::Delete()
  */
 static void
 soft_renderbuffer_delete(struct gl_context *ctx, struct gl_renderbuffer *rb)
 {
    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);

    free(srb->Buffer);
    srb->Buffer = NULL;
    _mesa_delete_renderbuffer(ctx, rb);
 }


 void
 _swrast_map_soft_renderbuffer(struct gl_context *ctx,
                               struct gl_renderbuffer *rb,
                               GLuint x, GLuint y, GLuint w, GLuint h,
                               GLbitfield mode,
                               GLubyte **out_map,
                               GLint *out_stride)
 {
    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
    GLubyte *map = srb->Buffer;
    int cpp = _mesa_get_format_bytes(rb->Format);
    int stride = rb->Width * cpp;

    if (!map) {
       *out_map = NULL;
       *out_stride = 0;
    }

    map += y * stride;
    map += x * cpp;

    *out_map = map;
    *out_stride = stride;
 }


 void
 _swrast_unmap_soft_renderbuffer(struct gl_context *ctx,
                                 struct gl_renderbuffer *rb)
 {
 }


 /**
  * Allocate a software-based renderbuffer.  This is called via the
  * ctx->Driver.NewRenderbuffer() function when the user creates a new
  * renderbuffer.
  * This would not be used for hardware-based renderbuffers.
  */
 struct gl_renderbuffer *
 _swrast_new_soft_renderbuffer(struct gl_context *ctx, GLuint name)
 {
    struct swrast_renderbuffer *srb = CALLOC_STRUCT(swrast_renderbuffer);
    if (srb) {
       _mesa_init_renderbuffer(&srb->Base, name);
       srb->Base.AllocStorage = soft_renderbuffer_storage;
       srb->Base.Delete = soft_renderbuffer_delete;
    }
    return &srb->Base;
 }


 /**
  * Add software-based color renderbuffers to the given framebuffer.
  * This is a helper routine for device drivers when creating a
  * window system framebuffer (not a user-created render/framebuffer).
  * Once this function is called, you can basically forget about this
  * renderbuffer; core Mesa will handle all the buffer management and
  * rendering!
  */
 static GLboolean
 add_color_renderbuffers(struct gl_context *ctx, struct gl_framebuffer *fb,
                         GLuint rgbBits, GLuint alphaBits,
                         GLboolean frontLeft, GLboolean backLeft,
                         GLboolean frontRight, GLboolean backRight)
 {
    gl_buffer_index b;

    if (rgbBits > 16 || alphaBits > 16) {
       _mesa_problem(ctx,
                     "Unsupported bit depth in add_color_renderbuffers");
       return GL_FALSE;
    }

    assert(MAX_COLOR_ATTACHMENTS >= 4);

    for (b = BUFFER_FRONT_LEFT; b <= BUFFER_BACK_RIGHT; b++) {
       struct gl_renderbuffer *rb;

       if (b == BUFFER_FRONT_LEFT && !frontLeft)
          continue;
       else if (b == BUFFER_BACK_LEFT && !backLeft)
          continue;
       else if (b == BUFFER_FRONT_RIGHT && !frontRight)
          continue;
       else if (b == BUFFER_BACK_RIGHT && !backRight)
          continue;

       assert(fb->Attachment[b].Renderbuffer == NULL);

       rb = ctx->Driver.NewRenderbuffer(ctx, 0);
       if (!rb) {
          _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating color buffer");
          return GL_FALSE;
       }

       rb->InternalFormat = GL_RGBA;

       rb->AllocStorage = soft_renderbuffer_storage;
       _mesa_add_renderbuffer(fb, b, rb);
    }

    return GL_TRUE;
 }


 /**
  * Add a software-based depth renderbuffer to the given framebuffer.
  * This is a helper routine for device drivers when creating a
  * window system framebuffer (not a user-created render/framebuffer).
  * Once this function is called, you can basically forget about this
  * renderbuffer; core Mesa will handle all the buffer management and
  * rendering!
  */
 static GLboolean
 add_depth_renderbuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
                        GLuint depthBits)
 {
    struct gl_renderbuffer *rb;

    if (depthBits > 32) {
       _mesa_problem(ctx,
                     "Unsupported depthBits in add_depth_renderbuffer");
       return GL_FALSE;
    }

    assert(fb->Attachment[BUFFER_DEPTH].Renderbuffer == NULL);

    rb = _swrast_new_soft_renderbuffer(ctx, 0);
    if (!rb) {
       _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating depth buffer");
       return GL_FALSE;
    }

    if (depthBits <= 16) {
       rb->InternalFormat = GL_DEPTH_COMPONENT16;
    }
    else if (depthBits <= 24) {
       rb->InternalFormat = GL_DEPTH_COMPONENT24;
    }
    else {
       rb->InternalFormat = GL_DEPTH_COMPONENT32;
    }

    rb->AllocStorage = soft_renderbuffer_storage;
    _mesa_add_renderbuffer(fb, BUFFER_DEPTH, rb);

    return GL_TRUE;
 }


 /**
  * Add a software-based stencil renderbuffer to the given framebuffer.
  * This is a helper routine for device drivers when creating a
  * window system framebuffer (not a user-created render/framebuffer).
  * Once this function is called, you can basically forget about this
  * renderbuffer; core Mesa will handle all the buffer management and
  * rendering!
  */
 static GLboolean
 add_stencil_renderbuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
                          GLuint stencilBits)
 {
    struct gl_renderbuffer *rb;

    if (stencilBits > 16) {
       _mesa_problem(ctx,
                   "Unsupported stencilBits in add_stencil_renderbuffer");
       return GL_FALSE;
    }

    assert(fb->Attachment[BUFFER_STENCIL].Renderbuffer == NULL);

    rb = _swrast_new_soft_renderbuffer(ctx, 0);
    if (!rb) {
       _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating stencil buffer");
       return GL_FALSE;
    }

    assert(stencilBits <= 8);
    rb->InternalFormat = GL_STENCIL_INDEX8;

    rb->AllocStorage = soft_renderbuffer_storage;
    _mesa_add_renderbuffer(fb, BUFFER_STENCIL, rb);

    return GL_TRUE;
 }


 static GLboolean
 add_depth_stencil_renderbuffer(struct gl_context *ctx,
                                struct gl_framebuffer *fb)
 {
    struct gl_renderbuffer *rb;

    assert(fb->Attachment[BUFFER_DEPTH].Renderbuffer == NULL);
    assert(fb->Attachment[BUFFER_STENCIL].Renderbuffer == NULL);

    rb = _swrast_new_soft_renderbuffer(ctx, 0);
    if (!rb) {
       _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating depth+stencil buffer");
       return GL_FALSE;
    }

    rb->InternalFormat = GL_DEPTH_STENCIL;

    rb->AllocStorage = soft_renderbuffer_storage;
    _mesa_add_renderbuffer(fb, BUFFER_DEPTH, rb);
    _mesa_add_renderbuffer(fb, BUFFER_STENCIL, rb);

    return GL_TRUE;
 }


 /**
  * Add a software-based accumulation renderbuffer to the given framebuffer.
  * This is a helper routine for device drivers when creating a
  * window system framebuffer (not a user-created render/framebuffer).
  * Once this function is called, you can basically forget about this
  * renderbuffer; core Mesa will handle all the buffer management and
  * rendering!
  */
 static GLboolean
 add_accum_renderbuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
                        GLuint redBits, GLuint greenBits,
                        GLuint blueBits, GLuint alphaBits)
 {
    struct gl_renderbuffer *rb;

    if (redBits > 16 || greenBits > 16 || blueBits > 16 || alphaBits > 16) {
       _mesa_problem(ctx,
                     "Unsupported accumBits in add_accum_renderbuffer");
       return GL_FALSE;
    }

    assert(fb->Attachment[BUFFER_ACCUM].Renderbuffer == NULL);

    rb = _swrast_new_soft_renderbuffer(ctx, 0);
    if (!rb) {
       _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating accum buffer");
       return GL_FALSE;
    }

    rb->InternalFormat = GL_RGBA16_SNORM;
    rb->AllocStorage = soft_renderbuffer_storage;
    _mesa_add_renderbuffer(fb, BUFFER_ACCUM, rb);

    return GL_TRUE;
 }


 /**
  * Add a software-based aux renderbuffer to the given framebuffer.
  * This is a helper routine for device drivers when creating a
  * window system framebuffer (not a user-created render/framebuffer).
  * Once this function is called, you can basically forget about this
  * renderbuffer; core Mesa will handle all the buffer management and
  * rendering!
  *
  * NOTE: color-index aux buffers not supported.
  */
 static GLboolean
 add_aux_renderbuffers(struct gl_context *ctx, struct gl_framebuffer *fb,
                       GLuint colorBits, GLuint numBuffers)
 {
    GLuint i;

    if (colorBits > 16) {
       _mesa_problem(ctx,
                     "Unsupported colorBits in add_aux_renderbuffers");
       return GL_FALSE;
    }

    assert(numBuffers <= MAX_AUX_BUFFERS);

    for (i = 0; i < numBuffers; i++) {
       struct gl_renderbuffer *rb = _swrast_new_soft_renderbuffer(ctx, 0);

       assert(fb->Attachment[BUFFER_AUX0 + i].Renderbuffer == NULL);

       if (!rb) {
          _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating aux buffer");
          return GL_FALSE;
       }

       assert (colorBits <= 8);
       rb->InternalFormat = GL_RGBA;

       rb->AllocStorage = soft_renderbuffer_storage;
       _mesa_add_renderbuffer(fb, BUFFER_AUX0 + i, rb);
    }
    return GL_TRUE;
 }


 /**
  * Create/attach software-based renderbuffers to the given framebuffer.
  * This is a helper routine for device drivers.  Drivers can just as well
  * call the individual _mesa_add_*_renderbuffer() routines directly.
  */
 void
 _swrast_add_soft_renderbuffers(struct gl_framebuffer *fb,
                                GLboolean color,
                                GLboolean depth,
                                GLboolean stencil,
                                GLboolean accum,
                                GLboolean alpha,
                                GLboolean aux)
 {
    GLboolean frontLeft = GL_TRUE;
    GLboolean backLeft = fb->Visual.doubleBufferMode;
    GLboolean frontRight = fb->Visual.stereoMode;
    GLboolean backRight = fb->Visual.stereoMode && fb->Visual.doubleBufferMode;

    if (color) {
       assert(fb->Visual.redBits == fb->Visual.greenBits);
       assert(fb->Visual.redBits == fb->Visual.blueBits);
       add_color_renderbuffers(NULL, fb,
                               fb->Visual.redBits,
                               fb->Visual.alphaBits,
                               frontLeft, backLeft,
                               frontRight, backRight);
    }

 #if 0
    /* This is pretty much for debugging purposes only since there's a perf
     * hit for using combined depth/stencil in swrast.
     */
    if (depth && fb->Visual.depthBits == 24 &&
        stencil && fb->Visual.stencilBits == 8) {
       /* use combined depth/stencil buffer */
       add_depth_stencil_renderbuffer(NULL, fb);
    }
    else
 #else
    (void) add_depth_stencil_renderbuffer;
 #endif
    {
       if (depth) {
          assert(fb->Visual.depthBits > 0);
          add_depth_renderbuffer(NULL, fb, fb->Visual.depthBits);
       }

       if (stencil) {
          assert(fb->Visual.stencilBits > 0);
          add_stencil_renderbuffer(NULL, fb, fb->Visual.stencilBits);
       }
    }

    if (accum) {
       assert(fb->Visual.accumRedBits > 0);
       assert(fb->Visual.accumGreenBits > 0);
       assert(fb->Visual.accumBlueBits > 0);
       add_accum_renderbuffer(NULL, fb,
                              fb->Visual.accumRedBits,
                              fb->Visual.accumGreenBits,
                              fb->Visual.accumBlueBits,
                              fb->Visual.accumAlphaBits);
    }

    if (aux) {
       assert(fb->Visual.numAuxBuffers > 0);
       add_aux_renderbuffers(NULL, fb, fb->Visual.redBits,
                             fb->Visual.numAuxBuffers);
    }

 #if 0
    if (multisample) {
       /* maybe someday */
    }
 #endif
 }


 static void
 map_attachment(struct gl_context *ctx,
                  struct gl_framebuffer *fb,
                  gl_buffer_index buffer)
 {
    struct gl_texture_object *texObj = fb->Attachment[buffer].Texture;
    struct gl_renderbuffer *rb = fb->Attachment[buffer].Renderbuffer;
    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);

    if (texObj) {
       /* map texture image (render to texture) */
       const GLuint level = fb->Attachment[buffer].TextureLevel;
       const GLuint face = fb->Attachment[buffer].CubeMapFace;
       const GLuint slice = fb->Attachment[buffer].Zoffset;
       struct gl_texture_image *texImage = texObj->Image[face][level];
       if (texImage) {
          ctx->Driver.MapTextureImage(ctx, texImage, slice,
                                      0, 0, texImage->Width, texImage->Height,
                                      GL_MAP_READ_BIT | GL_MAP_WRITE_BIT,
                                      &srb->Map, &srb->RowStride);
       }
    }
    else if (rb) {
       /* Map ordinary renderbuffer */
       ctx->Driver.MapRenderbuffer(ctx, rb,
                                   0, 0, rb->Width, rb->Height,
                                   GL_MAP_READ_BIT | GL_MAP_WRITE_BIT,
                                   &srb->Map, &srb->RowStride);
    }

    assert(srb->Map);
 }


 static void
 unmap_attachment(struct gl_context *ctx,
                    struct gl_framebuffer *fb,
                    gl_buffer_index buffer)
 {
    struct gl_texture_object *texObj = fb->Attachment[buffer].Texture;
    struct gl_renderbuffer *rb = fb->Attachment[buffer].Renderbuffer;
    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);

    if (texObj) {
       /* unmap texture image (render to texture) */
       const GLuint level = fb->Attachment[buffer].TextureLevel;
       const GLuint face = fb->Attachment[buffer].CubeMapFace;
       const GLuint slice = fb->Attachment[buffer].Zoffset;
       struct gl_texture_image *texImage = texObj->Image[face][level];
       if (texImage) {
          ctx->Driver.UnmapTextureImage(ctx, texImage, slice);
       }
    }
    else if (rb) {
       /* unmap ordinary renderbuffer */
       ctx->Driver.UnmapRenderbuffer(ctx, rb);
    }

    srb->Map = NULL;
 }


 /**
  * Determine what type to use (ubyte vs. float) for span colors for the
  * given renderbuffer.
  * See also _swrast_write_rgba_span().
  */
 static void
 find_renderbuffer_colortype(struct gl_renderbuffer *rb)
 {
    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
    GLuint rbMaxBits = _mesa_get_format_max_bits(rb->Format);
    GLenum rbDatatype = _mesa_get_format_datatype(rb->Format);

    if (rbDatatype == GL_UNSIGNED_NORMALIZED && rbMaxBits <= 8) {
       /* the buffer's values fit in GLubyte values */
       srb->ColorType = GL_UNSIGNED_BYTE;
    }
    else {
       /* use floats otherwise */
       srb->ColorType = GL_FLOAT;
    }
 }


 /**
  * Map the renderbuffers we'll use for tri/line/point rendering.
  */
 void
 _swrast_map_renderbuffers(struct gl_context *ctx)
 {
    struct gl_framebuffer *fb = ctx->DrawBuffer;
    struct gl_renderbuffer *depthRb, *stencilRb;
    GLuint buf;

    depthRb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
    if (depthRb) {
       /* map depth buffer */
       map_attachment(ctx, fb, BUFFER_DEPTH);
    }

    stencilRb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
    if (stencilRb && stencilRb != depthRb) {
       /* map stencil buffer */
       map_attachment(ctx, fb, BUFFER_STENCIL);
    }

    for (buf = 0; buf < fb->_NumColorDrawBuffers; buf++) {
       map_attachment(ctx, fb, fb->_ColorDrawBufferIndexes[buf]);
       find_renderbuffer_colortype(fb->_ColorDrawBuffers[buf]);
    }
 }


 /**
  * Unmap renderbuffers after rendering.
  */
 void
 _swrast_unmap_renderbuffers(struct gl_context *ctx)
 {
    struct gl_framebuffer *fb = ctx->DrawBuffer;
    struct gl_renderbuffer *depthRb, *stencilRb;
    GLuint buf;

    depthRb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
    if (depthRb) {
       /* map depth buffer */
       unmap_attachment(ctx, fb, BUFFER_DEPTH);
    }

    stencilRb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
    if (stencilRb && stencilRb != depthRb) {
       /* map stencil buffer */
       unmap_attachment(ctx, fb, BUFFER_STENCIL);
    }

    for (buf = 0; buf < fb->_NumColorDrawBuffers; buf++) {
       unmap_attachment(ctx, fb, fb->_ColorDrawBufferIndexes[buf]);
    }
 }
	/*
	* Mesa 3-D graphics library
	* Version: 6.5
	*
	* Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included
	* in all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
	* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
	* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*/


	/**
	* Functions for allocating/managing software-based renderbuffers.
	* Also, routines for reading/writing software-based renderbuffer data as
	* ubytes, ushorts, uints, etc.
	*/


	#include "main/glheader.h"
	#include "main/imports.h"
	#include "main/context.h"
	#include "main/fbobject.h"
	#include "main/formats.h"
	#include "main/mtypes.h"
	#include "main/renderbuffer.h"
	#include "swrast/s_context.h"
	#include "swrast/s_renderbuffer.h"


	/**
	* This is a software fallback for the gl_renderbuffer->AllocStorage
	* function.
	* Device drivers will typically override this function for the buffers
	* which it manages (typically color buffers, Z and stencil).
	* Other buffers (like software accumulation and aux buffers) which the driver
	* doesn't manage can be handled with this function.
	*
	* This one multi-purpose function can allocate stencil, depth, accum, color
	* or color-index buffers!
	*/
	static GLboolean
	soft_renderbuffer_storage(struct gl_context ctx, struct gl_renderbuffer rb,
	GLenum internalFormat,
	GLuint width, GLuint height)
	{
	struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
	GLuint bpp;

	switch (internalFormat) {
	case GL_RGB:
	case GL_R3_G3_B2:
	case GL_RGB4:
	case GL_RGB5:
	case GL_RGB8:
	case GL_RGB10:
	case GL_RGB12:
	case GL_RGB16:
	rb->Format = MESA_FORMAT_RGB888;
	break;
	case GL_RGBA:
	case GL_RGBA2:
	case GL_RGBA4:
	case GL_RGB5_A1:
	case GL_RGBA8:
	#if 1
	case GL_RGB10_A2:
	case GL_RGBA12:
	#endif
	if (_mesa_little_endian())
	rb->Format = MESA_FORMAT_RGBA8888_REV;
	else
	rb->Format = MESA_FORMAT_RGBA8888;
	break;
	case GL_RGBA16:
	case GL_RGBA16_SNORM:
	/* for accum buffer */
	rb->Format = MESA_FORMAT_SIGNED_RGBA_16;
	break;
	case GL_STENCIL_INDEX:
	case GL_STENCIL_INDEX1_EXT:
	case GL_STENCIL_INDEX4_EXT:
	case GL_STENCIL_INDEX8_EXT:
	case GL_STENCIL_INDEX16_EXT:
	rb->Format = MESA_FORMAT_S8;
	break;
	case GL_DEPTH_COMPONENT:
	case GL_DEPTH_COMPONENT16:
	rb->Format = MESA_FORMAT_Z16;
	break;
	case GL_DEPTH_COMPONENT24:
	rb->Format = MESA_FORMAT_X8_Z24;
	break;
	case GL_DEPTH_COMPONENT32:
	rb->Format = MESA_FORMAT_Z32;
	break;
	case GL_DEPTH_STENCIL_EXT:
	case GL_DEPTH24_STENCIL8_EXT:
	rb->Format = MESA_FORMAT_Z24_S8;
	break;
	default:
	/* unsupported format */
	return GL_FALSE;
	}

	bpp = _mesa_get_format_bytes(rb->Format);

	/* free old buffer storage */
	if (srb->Buffer) {
	free(srb->Buffer);
	srb->Buffer = NULL;
	}

	srb->RowStride = width * bpp;

	if (width > 0 && height > 0) {
	/* allocate new buffer storage */
	srb->Buffer = malloc(srb->RowStride * height);

	if (srb->Buffer == NULL) {
	rb->Width = 0;
	rb->Height = 0;
	_mesa_error(ctx, GL_OUT_OF_MEMORY,
	"software renderbuffer allocation (%d x %d x %d)",
	width, height, bpp);
	return GL_FALSE;
	}
	}

	rb->Width = width;
	rb->Height = height;
	rb->_BaseFormat = _mesa_base_fbo_format(ctx, internalFormat);

	if (rb->Name == 0 &&
	internalFormat == GL_RGBA16_SNORM &&
	rb->_BaseFormat == 0) {
	/* NOTE: This is a special case just for accumulation buffers.
	* This is a very limited use case- there's no snorm texturing or
	* rendering going on.
	*/
	rb->_BaseFormat = GL_RGBA;
	}
	else {
	/* the internalFormat should have been error checked long ago */
	ASSERT(rb->_BaseFormat);
	}

	return GL_TRUE;
	}


	/**
	* Called via gl_renderbuffer::Delete()
	*/
	static void
	soft_renderbuffer_delete(struct gl_context ctx, struct gl_renderbuffer rb)
	{
	struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);

	free(srb->Buffer);
	srb->Buffer = NULL;
	_mesa_delete_renderbuffer(ctx, rb);
	}


	void
	_swrast_map_soft_renderbuffer(struct gl_context *ctx,
	struct gl_renderbuffer *rb,
	GLuint x, GLuint y, GLuint w, GLuint h,
	GLbitfield mode,
	GLubyte **out_map,
	GLint *out_stride)
	{
	struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
	GLubyte *map = srb->Buffer;
	int cpp = _mesa_get_format_bytes(rb->Format);
	int stride = rb->Width * cpp;

	if (!map) {
	*out_map = NULL;
	*out_stride = 0;
	}

	map += y * stride;
	map += x * cpp;

	*out_map = map;
	*out_stride = stride;
	}


	void
	_swrast_unmap_soft_renderbuffer(struct gl_context *ctx,
	struct gl_renderbuffer *rb)
	{
	}



	/**
	* Allocate a software-based renderbuffer. This is called via the
	* ctx->Driver.NewRenderbuffer() function when the user creates a new
	* renderbuffer.
	* This would not be used for hardware-based renderbuffers.
	*/
	struct gl_renderbuffer *
	_swrast_new_soft_renderbuffer(struct gl_context *ctx, GLuint name)
	{
	struct swrast_renderbuffer *srb = CALLOC_STRUCT(swrast_renderbuffer);
	if (srb) {
	_mesa_init_renderbuffer(&srb->Base, name);
	srb->Base.AllocStorage = soft_renderbuffer_storage;
	srb->Base.Delete = soft_renderbuffer_delete;
	}
	return &srb->Base;
	}


	/**
	* Add software-based color renderbuffers to the given framebuffer.
	* This is a helper routine for device drivers when creating a
	* window system framebuffer (not a user-created render/framebuffer).
	* Once this function is called, you can basically forget about this
	* renderbuffer; core Mesa will handle all the buffer management and
	* rendering!
	*/
	static GLboolean
	add_color_renderbuffers(struct gl_context ctx, struct gl_framebuffer fb,
	GLuint rgbBits, GLuint alphaBits,
	GLboolean frontLeft, GLboolean backLeft,
	GLboolean frontRight, GLboolean backRight)
	{
	gl_buffer_index b;

	if (rgbBits > 16 \|\| alphaBits > 16) {
	_mesa_problem(ctx,
	"Unsupported bit depth in add_color_renderbuffers");
	return GL_FALSE;
	}

	assert(MAX_COLOR_ATTACHMENTS >= 4);

	for (b = BUFFER_FRONT_LEFT; b <= BUFFER_BACK_RIGHT; b++) {
	struct gl_renderbuffer *rb;

	if (b == BUFFER_FRONT_LEFT && !frontLeft)
	continue;
	else if (b == BUFFER_BACK_LEFT && !backLeft)
	continue;
	else if (b == BUFFER_FRONT_RIGHT && !frontRight)
	continue;
	else if (b == BUFFER_BACK_RIGHT && !backRight)
	continue;

	assert(fb->Attachment[b].Renderbuffer == NULL);

	rb = ctx->Driver.NewRenderbuffer(ctx, 0);
	if (!rb) {
	_mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating color buffer");
	return GL_FALSE;
	}

	rb->InternalFormat = GL_RGBA;

	rb->AllocStorage = soft_renderbuffer_storage;
	_mesa_add_renderbuffer(fb, b, rb);
	}

	return GL_TRUE;
	}


	/**
	* Add a software-based depth renderbuffer to the given framebuffer.
	* This is a helper routine for device drivers when creating a
	* window system framebuffer (not a user-created render/framebuffer).
	* Once this function is called, you can basically forget about this
	* renderbuffer; core Mesa will handle all the buffer management and
	* rendering!
	*/
	static GLboolean
	add_depth_renderbuffer(struct gl_context ctx, struct gl_framebuffer fb,
	GLuint depthBits)
	{
	struct gl_renderbuffer *rb;

	if (depthBits > 32) {
	_mesa_problem(ctx,
	"Unsupported depthBits in add_depth_renderbuffer");
	return GL_FALSE;
	}

	assert(fb->Attachment[BUFFER_DEPTH].Renderbuffer == NULL);

	rb = _swrast_new_soft_renderbuffer(ctx, 0);
	if (!rb) {
	_mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating depth buffer");
	return GL_FALSE;
	}

	if (depthBits <= 16) {
	rb->InternalFormat = GL_DEPTH_COMPONENT16;
	}
	else if (depthBits <= 24) {
	rb->InternalFormat = GL_DEPTH_COMPONENT24;
	}
	else {
	rb->InternalFormat = GL_DEPTH_COMPONENT32;
	}

	rb->AllocStorage = soft_renderbuffer_storage;
	_mesa_add_renderbuffer(fb, BUFFER_DEPTH, rb);

	return GL_TRUE;
	}


	/**
	* Add a software-based stencil renderbuffer to the given framebuffer.
	* This is a helper routine for device drivers when creating a
	* window system framebuffer (not a user-created render/framebuffer).
	* Once this function is called, you can basically forget about this
	* renderbuffer; core Mesa will handle all the buffer management and
	* rendering!
	*/
	static GLboolean
	add_stencil_renderbuffer(struct gl_context ctx, struct gl_framebuffer fb,
	GLuint stencilBits)
	{
	struct gl_renderbuffer *rb;

	if (stencilBits > 16) {
	_mesa_problem(ctx,
	"Unsupported stencilBits in add_stencil_renderbuffer");
	return GL_FALSE;
	}

	assert(fb->Attachment[BUFFER_STENCIL].Renderbuffer == NULL);

	rb = _swrast_new_soft_renderbuffer(ctx, 0);
	if (!rb) {
	_mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating stencil buffer");
	return GL_FALSE;
	}

	assert(stencilBits <= 8);
	rb->InternalFormat = GL_STENCIL_INDEX8;

	rb->AllocStorage = soft_renderbuffer_storage;
	_mesa_add_renderbuffer(fb, BUFFER_STENCIL, rb);

	return GL_TRUE;
	}


	static GLboolean
	add_depth_stencil_renderbuffer(struct gl_context *ctx,
	struct gl_framebuffer *fb)
	{
	struct gl_renderbuffer *rb;

	assert(fb->Attachment[BUFFER_DEPTH].Renderbuffer == NULL);
	assert(fb->Attachment[BUFFER_STENCIL].Renderbuffer == NULL);

	rb = _swrast_new_soft_renderbuffer(ctx, 0);
	if (!rb) {
	_mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating depth+stencil buffer");
	return GL_FALSE;
	}

	rb->InternalFormat = GL_DEPTH_STENCIL;

	rb->AllocStorage = soft_renderbuffer_storage;
	_mesa_add_renderbuffer(fb, BUFFER_DEPTH, rb);
	_mesa_add_renderbuffer(fb, BUFFER_STENCIL, rb);

	return GL_TRUE;
	}


	/**
	* Add a software-based accumulation renderbuffer to the given framebuffer.
	* This is a helper routine for device drivers when creating a
	* window system framebuffer (not a user-created render/framebuffer).
	* Once this function is called, you can basically forget about this
	* renderbuffer; core Mesa will handle all the buffer management and
	* rendering!
	*/
	static GLboolean
	add_accum_renderbuffer(struct gl_context ctx, struct gl_framebuffer fb,
	GLuint redBits, GLuint greenBits,
	GLuint blueBits, GLuint alphaBits)
	{
	struct gl_renderbuffer *rb;

	if (redBits > 16 \|\| greenBits > 16 \|\| blueBits > 16 \|\| alphaBits > 16) {
	_mesa_problem(ctx,
	"Unsupported accumBits in add_accum_renderbuffer");
	return GL_FALSE;
	}

	assert(fb->Attachment[BUFFER_ACCUM].Renderbuffer == NULL);

	rb = _swrast_new_soft_renderbuffer(ctx, 0);
	if (!rb) {
	_mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating accum buffer");
	return GL_FALSE;
	}

	rb->InternalFormat = GL_RGBA16_SNORM;
	rb->AllocStorage = soft_renderbuffer_storage;
	_mesa_add_renderbuffer(fb, BUFFER_ACCUM, rb);

	return GL_TRUE;
	}



	/**
	* Add a software-based aux renderbuffer to the given framebuffer.
	* This is a helper routine for device drivers when creating a
	* window system framebuffer (not a user-created render/framebuffer).
	* Once this function is called, you can basically forget about this
	* renderbuffer; core Mesa will handle all the buffer management and
	* rendering!
	*
	* NOTE: color-index aux buffers not supported.
	*/
	static GLboolean
	add_aux_renderbuffers(struct gl_context ctx, struct gl_framebuffer fb,
	GLuint colorBits, GLuint numBuffers)
	{
	GLuint i;

	if (colorBits > 16) {
	_mesa_problem(ctx,
	"Unsupported colorBits in add_aux_renderbuffers");
	return GL_FALSE;
	}

	assert(numBuffers <= MAX_AUX_BUFFERS);

	for (i = 0; i < numBuffers; i++) {
	struct gl_renderbuffer *rb = _swrast_new_soft_renderbuffer(ctx, 0);

	assert(fb->Attachment[BUFFER_AUX0 + i].Renderbuffer == NULL);

	if (!rb) {
	_mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating aux buffer");
	return GL_FALSE;
	}

	assert (colorBits <= 8);
	rb->InternalFormat = GL_RGBA;

	rb->AllocStorage = soft_renderbuffer_storage;
	_mesa_add_renderbuffer(fb, BUFFER_AUX0 + i, rb);
	}
	return GL_TRUE;
	}


	/**
	* Create/attach software-based renderbuffers to the given framebuffer.
	* This is a helper routine for device drivers. Drivers can just as well
	* call the individual _mesa_add_*_renderbuffer() routines directly.
	*/
	void
	_swrast_add_soft_renderbuffers(struct gl_framebuffer *fb,
	GLboolean color,
	GLboolean depth,
	GLboolean stencil,
	GLboolean accum,
	GLboolean alpha,
	GLboolean aux)
	{
	GLboolean frontLeft = GL_TRUE;
	GLboolean backLeft = fb->Visual.doubleBufferMode;
	GLboolean frontRight = fb->Visual.stereoMode;
	GLboolean backRight = fb->Visual.stereoMode && fb->Visual.doubleBufferMode;

	if (color) {
	assert(fb->Visual.redBits == fb->Visual.greenBits);
	assert(fb->Visual.redBits == fb->Visual.blueBits);
	add_color_renderbuffers(NULL, fb,
	fb->Visual.redBits,
	fb->Visual.alphaBits,
	frontLeft, backLeft,
	frontRight, backRight);
	}

	#if 0
	/* This is pretty much for debugging purposes only since there's a perf
	* hit for using combined depth/stencil in swrast.
	*/
	if (depth && fb->Visual.depthBits == 24 &&
	stencil && fb->Visual.stencilBits == 8) {
	/* use combined depth/stencil buffer */
	add_depth_stencil_renderbuffer(NULL, fb);
	}
	else
	#else
	(void) add_depth_stencil_renderbuffer;
	#endif
	{
	if (depth) {
	assert(fb->Visual.depthBits > 0);
	add_depth_renderbuffer(NULL, fb, fb->Visual.depthBits);
	}

	if (stencil) {
	assert(fb->Visual.stencilBits > 0);
	add_stencil_renderbuffer(NULL, fb, fb->Visual.stencilBits);
	}
	}

	if (accum) {
	assert(fb->Visual.accumRedBits > 0);
	assert(fb->Visual.accumGreenBits > 0);
	assert(fb->Visual.accumBlueBits > 0);
	add_accum_renderbuffer(NULL, fb,
	fb->Visual.accumRedBits,
	fb->Visual.accumGreenBits,
	fb->Visual.accumBlueBits,
	fb->Visual.accumAlphaBits);
	}

	if (aux) {
	assert(fb->Visual.numAuxBuffers > 0);
	add_aux_renderbuffers(NULL, fb, fb->Visual.redBits,
	fb->Visual.numAuxBuffers);
	}

	#if 0
	if (multisample) {
	/* maybe someday */
	}
	#endif
	}



	static void
	map_attachment(struct gl_context *ctx,
	struct gl_framebuffer *fb,
	gl_buffer_index buffer)
	{
	struct gl_texture_object *texObj = fb->Attachment[buffer].Texture;
	struct gl_renderbuffer *rb = fb->Attachment[buffer].Renderbuffer;
	struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);

	if (texObj) {
	/* map texture image (render to texture) */
	const GLuint level = fb->Attachment[buffer].TextureLevel;
	const GLuint face = fb->Attachment[buffer].CubeMapFace;
	const GLuint slice = fb->Attachment[buffer].Zoffset;
	struct gl_texture_image *texImage = texObj->Image[face][level];
	if (texImage) {
	ctx->Driver.MapTextureImage(ctx, texImage, slice,
	0, 0, texImage->Width, texImage->Height,
	GL_MAP_READ_BIT \| GL_MAP_WRITE_BIT,
	&srb->Map, &srb->RowStride);
	}
	}
	else if (rb) {
	/* Map ordinary renderbuffer */
	ctx->Driver.MapRenderbuffer(ctx, rb,
	0, 0, rb->Width, rb->Height,
	GL_MAP_READ_BIT \| GL_MAP_WRITE_BIT,
	&srb->Map, &srb->RowStride);
	}

	assert(srb->Map);
	}


	static void
	unmap_attachment(struct gl_context *ctx,
	struct gl_framebuffer *fb,
	gl_buffer_index buffer)
	{
	struct gl_texture_object *texObj = fb->Attachment[buffer].Texture;
	struct gl_renderbuffer *rb = fb->Attachment[buffer].Renderbuffer;
	struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);

	if (texObj) {
	/* unmap texture image (render to texture) */
	const GLuint level = fb->Attachment[buffer].TextureLevel;
	const GLuint face = fb->Attachment[buffer].CubeMapFace;
	const GLuint slice = fb->Attachment[buffer].Zoffset;
	struct gl_texture_image *texImage = texObj->Image[face][level];
	if (texImage) {
	ctx->Driver.UnmapTextureImage(ctx, texImage, slice);
	}
	}
	else if (rb) {
	/* unmap ordinary renderbuffer */
	ctx->Driver.UnmapRenderbuffer(ctx, rb);
	}

	srb->Map = NULL;
	}


	/**
	* Determine what type to use (ubyte vs. float) for span colors for the
	* given renderbuffer.
	* See also _swrast_write_rgba_span().
	*/
	static void
	find_renderbuffer_colortype(struct gl_renderbuffer *rb)
	{
	struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
	GLuint rbMaxBits = _mesa_get_format_max_bits(rb->Format);
	GLenum rbDatatype = _mesa_get_format_datatype(rb->Format);

	if (rbDatatype == GL_UNSIGNED_NORMALIZED && rbMaxBits <= 8) {
	/* the buffer's values fit in GLubyte values */
	srb->ColorType = GL_UNSIGNED_BYTE;
	}
	else {
	/* use floats otherwise */
	srb->ColorType = GL_FLOAT;
	}
	}


	/**
	* Map the renderbuffers we'll use for tri/line/point rendering.
	*/
	void
	_swrast_map_renderbuffers(struct gl_context *ctx)
	{
	struct gl_framebuffer *fb = ctx->DrawBuffer;
	struct gl_renderbuffer depthRb, stencilRb;
	GLuint buf;

	depthRb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
	if (depthRb) {
	/* map depth buffer */
	map_attachment(ctx, fb, BUFFER_DEPTH);
	}

	stencilRb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
	if (stencilRb && stencilRb != depthRb) {
	/* map stencil buffer */
	map_attachment(ctx, fb, BUFFER_STENCIL);
	}

	for (buf = 0; buf < fb->_NumColorDrawBuffers; buf++) {
	map_attachment(ctx, fb, fb->_ColorDrawBufferIndexes[buf]);
	find_renderbuffer_colortype(fb->_ColorDrawBuffers[buf]);
	}
	}


	/**
	* Unmap renderbuffers after rendering.
	*/
	void
	_swrast_unmap_renderbuffers(struct gl_context *ctx)
	{
	struct gl_framebuffer *fb = ctx->DrawBuffer;
	struct gl_renderbuffer depthRb, stencilRb;
	GLuint buf;

	depthRb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
	if (depthRb) {
	/* map depth buffer */
	unmap_attachment(ctx, fb, BUFFER_DEPTH);
	}

	stencilRb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
	if (stencilRb && stencilRb != depthRb) {
	/* map stencil buffer */
	unmap_attachment(ctx, fb, BUFFER_STENCIL);
	}

	for (buf = 0; buf < fb->_NumColorDrawBuffers; buf++) {
	unmap_attachment(ctx, fb, fb->_ColorDrawBufferIndexes[buf]);
	}
	}