pixel.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
 * Copyright (C) 1991-2000 Silicon Graphics, Inc. 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 including the dates of first publication and
 * either this permission notice or a reference to
 * http://oss.sgi.com/projects/FreeB/
 * 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
 * SILICON GRAPHICS, INC. 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.
 *
 * Except as contained in this notice, the name of Silicon Graphics, Inc.
 * shall not be used in advertising or otherwise to promote the sale, use or
 * other dealings in this Software without prior written authorization from
 * Silicon Graphics, Inc.
 */

#include "packrender.h"

static const GLubyte MsbToLsbTable[256] = {
    0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0,
    0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
    0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8,
    0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
    0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4,
    0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
    0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec,
    0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
    0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2,
    0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
    0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea,
    0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
    0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6,
    0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
    0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee,
    0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
    0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1,
    0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
    0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9,
    0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
    0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5,
    0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
    0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed,
    0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
    0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3,
    0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
    0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb,
    0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
    0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7,
    0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
    0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef,
    0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff,
};

static const GLubyte LowBitsMask[9] = {
    0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff,
};

static const GLubyte HighBitsMask[9] = {
    0x00, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff,
};


/*
** Copy bitmap data from clients packed memory applying unpacking modes as the
** data is transfered into the destImage buffer.  Return in modes the
** set of pixel modes that are to be done by the server.
*/
static void FillBitmap(__GLXcontext *gc, GLint width, GLint height,
		       GLenum format, const GLvoid *userdata,
		       GLubyte *destImage)
{
    const __GLXattribute * state = gc->client_state_private;
    GLint rowLength = state->storeUnpack.rowLength;
    GLint alignment = state->storeUnpack.alignment;
    GLint skipPixels = state->storeUnpack.skipPixels;
    GLint skipRows = state->storeUnpack.skipRows;
    GLint lsbFirst = state->storeUnpack.lsbFirst;
    GLint elementsLeft, bitOffset, currentByte, nextByte, highBitMask;
    GLint lowBitMask, i;
    GLint components, groupsPerRow, rowSize, padding, elementsPerRow;
    const GLubyte *start, *iter;

    if (rowLength > 0) {
	groupsPerRow = rowLength;
    } else {
	groupsPerRow = width;
    }
    components = __glElementsPerGroup(format,GL_BITMAP);
    rowSize = (groupsPerRow * components + 7) >> 3;
    padding = (rowSize % alignment);
    if (padding) {
	rowSize += alignment - padding;
    }
    start = ((const GLubyte*) userdata) + skipRows * rowSize + 
	((skipPixels * components) >> 3);
    bitOffset = (skipPixels * components) & 7;
    highBitMask = LowBitsMask[8-bitOffset];
    lowBitMask = HighBitsMask[bitOffset];
    elementsPerRow = width * components;
    for (i = 0; i < height; i++) {
	elementsLeft = elementsPerRow;
	iter = start;
	while (elementsLeft) {
	    /* First retrieve low bits from current byte */
	    if (lsbFirst) {
		currentByte = MsbToLsbTable[iter[0]];
	    } else {
		currentByte = iter[0];
	    }
	    if (bitOffset) {
		/* Need to read next byte to finish current byte */
		if (elementsLeft > (8 - bitOffset)) {
		    if (lsbFirst) {
			nextByte = MsbToLsbTable[iter[1]];
		    } else {
			nextByte = iter[1];
		    }
		    currentByte = 
			((currentByte & highBitMask) << bitOffset) |
			    ((nextByte & lowBitMask) >> (8 - bitOffset));
		} else {
		    currentByte = 
			((currentByte & highBitMask) << bitOffset);
		}
	    } 
	    if (elementsLeft >= 8) {
		*destImage = currentByte;
		elementsLeft -= 8;
	    } else {
		*destImage = currentByte & HighBitsMask[elementsLeft];
		elementsLeft = 0;
	    }
	    destImage++;
	    iter++;
	}
	start += rowSize;
    }
}

/*
** Extract array from user's data applying all pixel store modes.
** The internal packed array format used has LSB_FIRST = FALSE and 
** ALIGNMENT = 1.
*/
void __glFillImage(__GLXcontext *gc, GLint dim, GLint width, GLint height,
		   GLint depth, GLenum format, GLenum type,
		   const GLvoid *userdata, GLubyte *newimage, GLubyte *modes)
{
    const __GLXattribute * state = gc->client_state_private;
    GLint rowLength = state->storeUnpack.rowLength;
    GLint imageHeight = state->storeUnpack.imageHeight;
    GLint alignment = state->storeUnpack.alignment;
    GLint skipPixels = state->storeUnpack.skipPixels;
    GLint skipRows = state->storeUnpack.skipRows;
    GLint skipImages = state->storeUnpack.skipImages;
    GLint swapBytes = state->storeUnpack.swapEndian;
    GLint components, elementSize, rowSize, padding, groupsPerRow, groupSize;
    GLint elementsPerRow, imageSize, rowsPerImage, h, i, j, k;
    const GLubyte *start, *iter, *itera, *iterb, *iterc;
    GLubyte *iter2;

    if (type == GL_BITMAP) {
	FillBitmap(gc, width, height, format, userdata, newimage);
    } else {
	components = __glElementsPerGroup(format,type);
	if (rowLength > 0) {
	    groupsPerRow = rowLength;
	} else {
	    groupsPerRow = width;
	}
	if (imageHeight > 0) {
	    rowsPerImage = imageHeight;
	} else {
	    rowsPerImage = height;
	}

	elementSize = __glBytesPerElement(type);
	groupSize = elementSize * components;
	if (elementSize == 1) swapBytes = 0;

	rowSize = groupsPerRow * groupSize;
	padding = (rowSize % alignment);
	if (padding) {
	    rowSize += alignment - padding;
	}
	imageSize = rowSize * rowsPerImage;
	start = ((const GLubyte*) userdata) + skipImages * imageSize +
		skipRows * rowSize + skipPixels * groupSize;
	iter2 = newimage;
	elementsPerRow = width * components;

	if (swapBytes) {
	    itera = start;
	    for (h = 0; h < depth; h++) {
		iterb = itera;
		for (i = 0; i < height; i++) {
		    iterc = iterb;
		    for (j = 0; j < elementsPerRow; j++) {
			for (k = 1; k <= elementSize; k++) {
			    iter2[k-1] = iterc[elementSize - k];
			}
			iter2 += elementSize;
			iterc += elementSize;
		    }
		    iterb += rowSize;
		}
		itera += imageSize;
	    }
	} else {
	    itera = start;
	    for (h = 0; h < depth; h++) {
		if (rowSize == elementsPerRow * elementSize) {
		    /* Ha!  This is mondo easy! */
		    __GLX_MEM_COPY(iter2, itera,
				   elementsPerRow * elementSize * height);
		    iter2 += elementsPerRow * elementSize * height;
		} else {
		    iter = itera;
		    for (i = 0; i < height; i++) {
			__GLX_MEM_COPY(iter2, iter, elementsPerRow*elementSize);
			iter2 += elementsPerRow * elementSize;
			iter += rowSize;
		    }
		}
		itera += imageSize;
	    }    
	}
    }

    /* Setup store modes that describe what we just did */
    if (modes) {
       if ( dim < 3 ) {
	  (void) memcpy( modes, __glXDefaultPixelStore + 4, 20 );
       }
       else {
	  (void) memcpy( modes, __glXDefaultPixelStore + 0, 36 );
       }
    }
}

/*
** Empty a bitmap in LSB_FIRST=GL_FALSE and ALIGNMENT=4 format packing it
** into the clients memory using the pixel store PACK modes.
*/
static void EmptyBitmap(__GLXcontext *gc, GLint width, GLint height,
			GLenum format, const GLubyte *sourceImage,
			GLvoid *userdata)
{
    const __GLXattribute * state = gc->client_state_private;
    GLint rowLength = state->storePack.rowLength;
    GLint alignment = state->storePack.alignment;
    GLint skipPixels = state->storePack.skipPixels;
    GLint skipRows = state->storePack.skipRows;
    GLint lsbFirst = state->storePack.lsbFirst;
    GLint components, groupsPerRow, rowSize, padding, elementsPerRow;
    GLint sourceRowSize, sourcePadding, sourceSkip;
    GLubyte *start, *iter;
    GLint elementsLeft, bitOffset, currentByte, highBitMask, lowBitMask;
    GLint writeMask, i;
    GLubyte writeByte;

    components = __glElementsPerGroup(format,GL_BITMAP);
    if (rowLength > 0) {
	groupsPerRow = rowLength;
    } else {
	groupsPerRow = width;
    }

    rowSize = (groupsPerRow * components + 7) >> 3;
    padding = (rowSize % alignment);
    if (padding) {
	rowSize += alignment - padding;
    }
    sourceRowSize = (width * components + 7) >> 3;
    sourcePadding = (sourceRowSize % 4);
    if (sourcePadding) {
	sourceSkip = 4 - sourcePadding;
    } else {
	sourceSkip = 0;
    }
    start = ((GLubyte*) userdata) + skipRows * rowSize + 
	((skipPixels * components) >> 3);
    bitOffset = (skipPixels * components) & 7;
    highBitMask = LowBitsMask[8-bitOffset];
    lowBitMask = HighBitsMask[bitOffset];
    elementsPerRow = width * components;
    for (i = 0; i < height; i++) {
	elementsLeft = elementsPerRow;
	iter = start;
	writeMask = highBitMask;
	writeByte = 0;
	while (elementsLeft) {
	    /* Set up writeMask (to write to current byte) */
	    if (elementsLeft + bitOffset < 8) {
		/* Need to trim writeMask */
		writeMask &= HighBitsMask[bitOffset+elementsLeft];
	    }

	    if (lsbFirst) {
		currentByte = MsbToLsbTable[iter[0]];
	    } else {
		currentByte = iter[0];
	    }

	    if (bitOffset) {
		writeByte |= (sourceImage[0] >> bitOffset);
		currentByte = (currentByte & ~writeMask) | 
		    (writeByte & writeMask);
		writeByte = (sourceImage[0] << (8 - bitOffset));
	    } else {
		currentByte = (currentByte & ~writeMask) |
		    (sourceImage[0] & writeMask);
	    }

	    if (lsbFirst) {
		iter[0] = MsbToLsbTable[currentByte];
	    } else {
		iter[0] = currentByte;
	    }

	    if (elementsLeft >= 8) {
		elementsLeft -= 8;
	    } else {
		elementsLeft = 0;
	    }
	    sourceImage++;
	    iter++;
	    writeMask = 0xff;
	}
	if (writeByte) {
	    /* Some data left over that still needs writing */
	    writeMask &= lowBitMask;
	    if (lsbFirst) {
		currentByte = MsbToLsbTable[iter[0]];
	    } else {
		currentByte = iter[0];
	    }
	    currentByte = (currentByte & ~writeMask) | (writeByte & writeMask);
	    if (lsbFirst) {
		iter[0] = MsbToLsbTable[currentByte];
	    } else {
		iter[0] = currentByte;
	    }
	}
	start += rowSize;
	sourceImage += sourceSkip;
    }
}

/*
** Insert array into user's data applying all pixel store modes.
** The packed array format from the server is LSB_FIRST = FALSE,
** SWAP_BYTES = the current pixel storage pack mode, and ALIGNMENT = 4.
** Named __glEmptyImage() because it is the opposite of __glFillImage().
*/
/* ARGSUSED */
void __glEmptyImage(__GLXcontext *gc, GLint dim, GLint width, GLint height, 
		    GLint depth, GLenum format, GLenum type,
		    const GLubyte *sourceImage, GLvoid *userdata)
{
    const __GLXattribute * state = gc->client_state_private;
    GLint rowLength = state->storePack.rowLength;
    GLint imageHeight = state->storePack.imageHeight;
    GLint alignment = state->storePack.alignment;
    GLint skipPixels = state->storePack.skipPixels;
    GLint skipRows = state->storePack.skipRows;
    GLint skipImages = state->storePack.skipImages;
    GLint components, elementSize, rowSize, padding, groupsPerRow, groupSize;
    GLint elementsPerRow, sourceRowSize, sourcePadding, h, i;
    GLint imageSize, rowsPerImage;
    GLubyte *start, *iter, *itera;

    if (type == GL_BITMAP) {
	EmptyBitmap(gc, width, height, format, sourceImage, userdata);
    } else {
	components = __glElementsPerGroup(format,type);
	if (rowLength > 0) {
	    groupsPerRow = rowLength;
	} else {
	    groupsPerRow = width;
	}
	if (imageHeight > 0) {
	    rowsPerImage = imageHeight;
	} else {
	    rowsPerImage = height;
	}
	elementSize = __glBytesPerElement(type);
	groupSize = elementSize * components;
	rowSize = groupsPerRow * groupSize;
	padding = (rowSize % alignment);
	if (padding) {
	    rowSize += alignment - padding;
	}
	sourceRowSize = width * groupSize;
	sourcePadding = (sourceRowSize % 4);
	if (sourcePadding) {
	    sourceRowSize += 4 - sourcePadding;
	}
	imageSize = sourceRowSize * rowsPerImage;
	start = ((GLubyte*) userdata) + skipImages * imageSize +
		skipRows * rowSize + skipPixels * groupSize;
	elementsPerRow = width * components;

	itera = start;
	for (h = 0; h < depth; h++) {
	    if ((rowSize == sourceRowSize) && (sourcePadding == 0)) {
		/* Ha!  This is mondo easy! */
		__GLX_MEM_COPY(itera, sourceImage,
			       elementsPerRow * elementSize * height);
		sourceImage += elementsPerRow * elementSize * height;
	    } else {
		iter = itera;
		for (i = 0; i < height; i++) {
		    __GLX_MEM_COPY(iter, sourceImage,
				   elementsPerRow * elementSize);
		    sourceImage += sourceRowSize;
		    iter += rowSize;
		}
	    }
	    itera += imageSize;
	}
    }
}