/* $Id: s_alphabuf.c,v 1.15 2002/10/24 23:57:24 brianp Exp $ */ /* * Mesa 3-D graphics library * Version: 4.1 * * Copyright (C) 1999-2002 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. */ /* * Software alpha planes. Many frame buffers don't have alpha bits so * we simulate them in software. */ #include "glheader.h" #include "context.h" #include "imports.h" #include "s_context.h" #include "s_alphabuf.h" /* * Allocate a new front and back alpha buffer. */ void _mesa_alloc_alpha_buffers( GLframebuffer *buffer ) { const GLint bytes = buffer->Width * buffer->Height * sizeof(GLchan); ASSERT(buffer->UseSoftwareAlphaBuffers); if (buffer->FrontLeftAlpha) { MESA_PBUFFER_FREE( buffer->FrontLeftAlpha ); } buffer->FrontLeftAlpha = MESA_PBUFFER_ALLOC( bytes ); if (!buffer->FrontLeftAlpha) { /* out of memory */ _mesa_error( NULL, GL_OUT_OF_MEMORY, "Couldn't allocate front-left alpha buffer" ); } if (buffer->Visual.doubleBufferMode) { if (buffer->BackLeftAlpha) { MESA_PBUFFER_FREE( buffer->BackLeftAlpha ); } buffer->BackLeftAlpha = MESA_PBUFFER_ALLOC( bytes ); if (!buffer->BackLeftAlpha) { /* out of memory */ _mesa_error( NULL, GL_OUT_OF_MEMORY, "Couldn't allocate back-left alpha buffer" ); } } if (buffer->Visual.stereoMode) { if (buffer->FrontRightAlpha) { MESA_PBUFFER_FREE( buffer->FrontRightAlpha ); } buffer->FrontRightAlpha = MESA_PBUFFER_ALLOC( bytes ); if (!buffer->FrontRightAlpha) { /* out of memory */ _mesa_error( NULL, GL_OUT_OF_MEMORY, "Couldn't allocate front-right alpha buffer" ); } if (buffer->Visual.doubleBufferMode) { if (buffer->BackRightAlpha) { MESA_PBUFFER_FREE( buffer->BackRightAlpha ); } buffer->BackRightAlpha = MESA_PBUFFER_ALLOC( bytes ); if (!buffer->BackRightAlpha) { /* out of memory */ _mesa_error( NULL, GL_OUT_OF_MEMORY, "Couldn't allocate back-right alpha buffer" ); } } } } /* * Clear all the alpha buffers */ void _mesa_clear_alpha_buffers( GLcontext *ctx ) { const GLchan aclear = (GLchan) ctx->Color.ClearColor[3]; GLuint bufferBit; ASSERT(ctx->DrawBuffer->UseSoftwareAlphaBuffers); ASSERT(ctx->Color.ColorMask[ACOMP]); /* loop over four possible alpha buffers */ for (bufferBit = 1; bufferBit <= 8; bufferBit = bufferBit << 1) { if (bufferBit & ctx->Color._DrawDestMask) { GLchan *buffer; if (bufferBit == FRONT_LEFT_BIT) { buffer = (GLchan *) ctx->DrawBuffer->FrontLeftAlpha; } else if (bufferBit == FRONT_RIGHT_BIT) { buffer = (GLchan *) ctx->DrawBuffer->FrontRightAlpha; } else if (bufferBit == BACK_LEFT_BIT) { buffer = (GLchan *) ctx->DrawBuffer->BackLeftAlpha; } else { buffer = (GLchan *) ctx->DrawBuffer->BackRightAlpha; } if (ctx->Scissor.Enabled) { /* clear scissor region */ GLint j; GLint rowLen = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin; GLint rows = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin; GLint width = ctx->DrawBuffer->Width; GLchan *aptr = buffer + ctx->DrawBuffer->_Ymin * ctx->DrawBuffer->Width + ctx->DrawBuffer->_Xmin; for (j = 0; j < rows; j++) { #if CHAN_BITS == 8 MEMSET( aptr, aclear, rowLen ); #elif CHAN_BITS == 16 MEMSET16( aptr, aclear, rowLen ); #else GLint i; for (i = 0; i < rowLen; i++) { aptr[i] = aclear; } #endif aptr += width; } } else { /* clear whole buffer */ GLuint pixels = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height; #if CHAN_BITS == 8 MEMSET(buffer, aclear, pixels); #elif CHAN_BITS == 16 MEMSET16(buffer, aclear, pixels); #else GLuint i; for (i = 0; i < pixels; i++) { buffer[i] = aclear; } #endif } } } } static INLINE GLchan *get_alpha_buffer( GLcontext *ctx ) { SWcontext *swrast = SWRAST_CONTEXT(ctx); switch (swrast->CurrentBuffer) { case FRONT_LEFT_BIT: return (GLchan *) ctx->DrawBuffer->FrontLeftAlpha; break; case BACK_LEFT_BIT: return (GLchan *) ctx->DrawBuffer->BackLeftAlpha; break; case FRONT_RIGHT_BIT: return (GLchan *) ctx->DrawBuffer->FrontRightAlpha; break; case BACK_RIGHT_BIT: return (GLchan *) ctx->DrawBuffer->BackRightAlpha; break; default: _mesa_problem(ctx, "Bad CurrentBuffer in get_alpha_buffer()"); return (GLchan *) ctx->DrawBuffer->FrontLeftAlpha; } } void _mesa_write_alpha_span( GLcontext *ctx, GLuint n, GLint x, GLint y, CONST GLchan rgba[][4], const GLubyte mask[] ) { GLchan *buffer, *aptr; GLuint i; buffer = get_alpha_buffer(ctx); aptr = buffer + y * ctx->DrawBuffer->Width + x; if (mask) { for (i=0;iDrawBuffer->Width + x; if (mask) { for (i=0;iDrawBuffer->Width + x[i]; *aptr = rgba[i][ACOMP]; } } } else { for (i=0;iDrawBuffer->Width + x[i]; *aptr = rgba[i][ACOMP]; } } } void _mesa_write_mono_alpha_pixels( GLcontext *ctx, GLuint n, const GLint x[], const GLint y[], GLchan alpha, const GLubyte mask[] ) { GLchan *buffer; GLuint i; buffer = get_alpha_buffer(ctx); if (mask) { for (i=0;iDrawBuffer->Width + x[i]; *aptr = alpha; } } } else { for (i=0;iDrawBuffer->Width + x[i]; *aptr = alpha; } } } void _mesa_read_alpha_span( GLcontext *ctx, GLuint n, GLint x, GLint y, GLchan rgba[][4] ) { const GLchan *buffer, *aptr; GLuint i; buffer = get_alpha_buffer(ctx); aptr = buffer + y * ctx->DrawBuffer->Width + x; for (i = 0; i < n; i++) rgba[i][ACOMP] = *aptr++; } void _mesa_read_alpha_pixels( GLcontext *ctx, GLuint n, const GLint x[], const GLint y[], GLchan rgba[][4], const GLubyte mask[] ) { const GLchan *buffer; GLuint i; buffer = get_alpha_buffer(ctx); for (i = 0; i < n; i++) { if (mask[i]) { const GLchan *aptr = buffer + y[i] * ctx->DrawBuffer->Width + x[i]; rgba[i][ACOMP] = *aptr; } } }