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-rw-r--r--src/mesa/swrast/s_alphabuf.c313
1 files changed, 313 insertions, 0 deletions
diff --git a/src/mesa/swrast/s_alphabuf.c b/src/mesa/swrast/s_alphabuf.c
new file mode 100644
index 00000000000..ed7b9cbded1
--- /dev/null
+++ b/src/mesa/swrast/s_alphabuf.c
@@ -0,0 +1,313 @@
+
+/*
+ * Mesa 3-D graphics library
+ * Version: 3.5
+ *
+ * Copyright (C) 1999-2000 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 "mem.h"
+
+#include "s_alphabuf.h"
+
+
+
+
+#define ALPHA_DRAW_ADDR(X,Y) \
+ (ctx->DrawBuffer->Alpha + (Y) * ctx->DrawBuffer->Width + (X))
+
+#define ALPHA_READ_ADDR(X,Y) \
+ (ctx->ReadBuffer->Alpha + (Y) * ctx->ReadBuffer->Width + (X))
+
+
+
+/*
+ * Allocate new front/back/left/right alpha buffers.
+ * Input: ctx - the context
+ *
+ */
+static void
+alloc_alpha_buffers( GLcontext *ctx, GLframebuffer *buf )
+{
+ GLint bytes = buf->Width * buf->Height * sizeof(GLchan);
+
+ ASSERT(ctx->DrawBuffer->UseSoftwareAlphaBuffers);
+
+ if (buf->FrontLeftAlpha) {
+ FREE( buf->FrontLeftAlpha );
+ }
+ buf->FrontLeftAlpha = (GLchan *) MALLOC( bytes );
+ if (!buf->FrontLeftAlpha) {
+ /* out of memory */
+ gl_error( ctx, GL_OUT_OF_MEMORY,
+ "Couldn't allocate front-left alpha buffer" );
+ }
+
+ if (ctx->Visual.DBflag) {
+ if (buf->BackLeftAlpha) {
+ FREE( buf->BackLeftAlpha );
+ }
+ buf->BackLeftAlpha = (GLchan *) MALLOC( bytes );
+ if (!buf->BackLeftAlpha) {
+ /* out of memory */
+ gl_error( ctx, GL_OUT_OF_MEMORY,
+ "Couldn't allocate back-left alpha buffer" );
+ }
+ }
+
+ if (ctx->Visual.StereoFlag) {
+ if (buf->FrontRightAlpha) {
+ FREE( buf->FrontRightAlpha );
+ }
+ buf->FrontRightAlpha = (GLchan *) MALLOC( bytes );
+ if (!buf->FrontRightAlpha) {
+ /* out of memory */
+ gl_error( ctx, GL_OUT_OF_MEMORY,
+ "Couldn't allocate front-right alpha buffer" );
+ }
+
+ if (ctx->Visual.DBflag) {
+ if (buf->BackRightAlpha) {
+ FREE( buf->BackRightAlpha );
+ }
+ buf->BackRightAlpha = (GLchan *) MALLOC( bytes );
+ if (!buf->BackRightAlpha) {
+ /* out of memory */
+ gl_error( ctx, GL_OUT_OF_MEMORY,
+ "Couldn't allocate back-right alpha buffer" );
+ }
+ }
+ }
+
+ if (ctx->Color.DriverDrawBuffer == GL_FRONT_LEFT)
+ buf->Alpha = buf->FrontLeftAlpha;
+ else if (ctx->Color.DriverDrawBuffer == GL_BACK_LEFT)
+ buf->Alpha = buf->BackLeftAlpha;
+ else if (ctx->Color.DriverDrawBuffer == GL_FRONT_RIGHT)
+ buf->Alpha = buf->FrontRightAlpha;
+ else if (ctx->Color.DriverDrawBuffer == GL_BACK_RIGHT)
+ buf->Alpha = buf->BackRightAlpha;
+}
+
+
+/*
+ * Allocate a new front and back alpha buffer.
+ */
+void
+_mesa_alloc_alpha_buffers( GLcontext *ctx )
+{
+ alloc_alpha_buffers( ctx, ctx->DrawBuffer );
+ if (ctx->ReadBuffer != ctx->DrawBuffer) {
+ alloc_alpha_buffers( ctx, ctx->ReadBuffer );
+ }
+}
+
+
+/*
+ * Clear all the alpha buffers
+ */
+void
+_mesa_clear_alpha_buffers( GLcontext *ctx )
+{
+ const GLchan aclear = (GLint) (ctx->Color.ClearColor[3] * CHAN_MAXF);
+ 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 = ctx->DrawBuffer->FrontLeftAlpha;
+ }
+ else if (bufferBit == FRONT_RIGHT_BIT) {
+ buffer = ctx->DrawBuffer->FrontRightAlpha;
+ }
+ else if (bufferBit == BACK_LEFT_BIT) {
+ buffer = ctx->DrawBuffer->BackLeftAlpha;
+ }
+ else {
+ buffer = ctx->DrawBuffer->BackRightAlpha;
+ }
+
+ if (ctx->Scissor.Enabled) {
+ /* clear scissor region */
+ GLint j;
+ GLint rowLen = ctx->DrawBuffer->Xmax - ctx->DrawBuffer->Xmin + 1;
+ GLint rows = ctx->DrawBuffer->Ymax - ctx->DrawBuffer->Ymin + 1;
+ 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
+#error unexpected CHAN_BITS value
+#endif
+ aptr += rowLen;
+ }
+ }
+ else {
+ /* clear whole buffer */
+ GLuint bytes = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
+ MEMSET( buffer, aclear, bytes );
+ }
+ }
+ }
+}
+
+
+
+void
+_mesa_write_alpha_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
+ CONST GLchan rgba[][4], const GLubyte mask[] )
+{
+ GLchan *aptr = ALPHA_DRAW_ADDR( x, y );
+ GLuint i;
+
+ if (mask) {
+ for (i=0;i<n;i++) {
+ if (mask[i]) {
+ *aptr = rgba[i][ACOMP];
+ }
+ aptr++;
+ }
+ }
+ else {
+ for (i=0;i<n;i++) {
+ *aptr++ = rgba[i][ACOMP];
+ }
+ }
+}
+
+
+void
+_mesa_write_mono_alpha_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
+ GLchan alpha, const GLubyte mask[] )
+{
+ GLchan *aptr = ALPHA_DRAW_ADDR( x, y );
+ GLuint i;
+
+ if (mask) {
+ for (i=0;i<n;i++) {
+ if (mask[i]) {
+ *aptr = alpha;
+ }
+ aptr++;
+ }
+ }
+ else {
+ for (i=0;i<n;i++) {
+ *aptr++ = alpha;
+ }
+ }
+}
+
+
+void
+_mesa_write_alpha_pixels( GLcontext *ctx,
+ GLuint n, const GLint x[], const GLint y[],
+ CONST GLchan rgba[][4], const GLubyte mask[] )
+{
+ GLuint i;
+
+ if (mask) {
+ for (i=0;i<n;i++) {
+ if (mask[i]) {
+ GLchan *aptr = ALPHA_DRAW_ADDR( x[i], y[i] );
+ *aptr = rgba[i][ACOMP];
+ }
+ }
+ }
+ else {
+ for (i=0;i<n;i++) {
+ GLchan *aptr = ALPHA_DRAW_ADDR( x[i], y[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[] )
+{
+ GLuint i;
+
+ if (mask) {
+ for (i=0;i<n;i++) {
+ if (mask[i]) {
+ GLchan *aptr = ALPHA_DRAW_ADDR( x[i], y[i] );
+ *aptr = alpha;
+ }
+ }
+ }
+ else {
+ for (i=0;i<n;i++) {
+ GLchan *aptr = ALPHA_DRAW_ADDR( x[i], y[i] );
+ *aptr = alpha;
+ }
+ }
+}
+
+
+
+void
+_mesa_read_alpha_span( GLcontext *ctx,
+ GLuint n, GLint x, GLint y, GLchan rgba[][4] )
+{
+ GLchan *aptr = ALPHA_READ_ADDR( x, y );
+ GLuint i;
+ 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[] )
+{
+ GLuint i;
+ for (i=0;i<n;i++) {
+ if (mask[i]) {
+ GLchan *aptr = ALPHA_READ_ADDR( x[i], y[i] );
+ rgba[i][ACOMP] = *aptr;
+ }
+ }
+}
+
+
+
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