diff options
author | Brian Paul <brian.paul@tungstengraphics.com> | 2006-10-06 03:48:42 +0000 |
---|---|---|
committer | Brian Paul <brian.paul@tungstengraphics.com> | 2006-10-06 03:48:42 +0000 |
commit | 6e138dfa361c33b8e0adcf1cafa9781fb53e219d (patch) | |
tree | 9e2e761da73553aca84df150fe680967570aa746 /src | |
parent | fcb48e34229eba9db6835c24fcf8f8fde91b446a (diff) | |
download | external_mesa3d-6e138dfa361c33b8e0adcf1cafa9781fb53e219d.zip external_mesa3d-6e138dfa361c33b8e0adcf1cafa9781fb53e219d.tar.gz external_mesa3d-6e138dfa361c33b8e0adcf1cafa9781fb53e219d.tar.bz2 |
rewrite of read_fast_rgba_pixels()
Diffstat (limited to 'src')
-rw-r--r-- | src/mesa/swrast/s_readpix.c | 88 |
1 files changed, 37 insertions, 51 deletions
diff --git a/src/mesa/swrast/s_readpix.c b/src/mesa/swrast/s_readpix.c index 4c3be5a..a73bb81 100644 --- a/src/mesa/swrast/s_readpix.c +++ b/src/mesa/swrast/s_readpix.c @@ -193,9 +193,8 @@ read_stencil_pixels( GLcontext *ctx, /** - * Optimized glReadPixels for particular pixel formats: - * GL_UNSIGNED_BYTE, GL_RGBA - * when pixel scaling, biasing and mapping are disabled. + * Optimized glReadPixels for particular pixel formats when pixel + * scaling, biasing, mapping, etc. are disabled. */ static GLboolean read_fast_rgba_pixels( GLcontext *ctx, @@ -207,6 +206,10 @@ read_fast_rgba_pixels( GLcontext *ctx, { struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer; + /* clipping should have already been done */ + ASSERT(x + width <= rb->Width); + ASSERT(y + height <= rb->Height); + /* can't do scale, bias, mapping, etc */ if (ctx->_ImageTransferState) return GL_FALSE; @@ -215,57 +218,40 @@ read_fast_rgba_pixels( GLcontext *ctx, if (packing->Alignment != 1 || packing->SwapBytes || packing->LsbFirst) return GL_FALSE; - { - GLint srcX = x; - GLint srcY = y; - GLint readWidth = width; /* actual width read */ - GLint readHeight = height; /* actual height read */ - GLint skipPixels = packing->SkipPixels; - GLint skipRows = packing->SkipRows; - GLint rowLength; - - if (packing->RowLength > 0) - rowLength = packing->RowLength; - else - rowLength = width; - - /* - * Ready to read! - * The window region at (destX, destY) of size (readWidth, readHeight) - * will be read back. - * We'll write pixel data to buffer pointed to by "pixels" but we'll - * skip "skipRows" rows and skip "skipPixels" pixels/row. - */ -#if CHAN_BITS == 8 - if (format == GL_RGBA && type == GL_UNSIGNED_BYTE) -#elif CHAN_BITS == 16 - if (format == GL_RGBA && type == GL_UNSIGNED_SHORT) -#else - if (0) -#endif - { - GLchan *dest = (GLchan *) pixels - + (skipRows * rowLength + skipPixels) * 4; - GLint row; - - if (packing->Invert) { - /* start at top and go down */ - dest += (readHeight - 1) * rowLength * 4; - rowLength = -rowLength; - } + /* if the pixel format exactly matches the renderbuffer format */ + if (format == GL_RGBA && rb->DataType == type) { + GLint rowLength = (packing->RowLength > 0) ? packing->RowLength : width; + GLint pixelSize, row; + GLubyte *dest; - ASSERT(rb->GetRow); - for (row=0; row<readHeight; row++) { - rb->GetRow(ctx, rb, readWidth, srcX, srcY, dest); - dest += rowLength * 4; - srcY++; - } - return GL_TRUE; - } + if (type == GL_UNSIGNED_BYTE) + pixelSize = 4 * sizeof(GLubyte); + else if (type == GL_UNSIGNED_SHORT) + pixelSize = 4 * sizeof(GLushort); else { - /* can't do this format/type combination */ - return GL_FALSE; + ASSERT(type == GL_FLOAT); + pixelSize = 4 * sizeof(GLfloat); + } + + dest = (GLubyte *) pixels + + (packing->SkipRows * rowLength + packing->SkipPixels) * pixelSize; + + if (packing->Invert) { + /* start at top and go down */ + dest += (height - 1) * rowLength * pixelSize; + rowLength = -rowLength; + } + + ASSERT(rb->GetRow); + for (row = 0; row < height; row++) { + rb->GetRow(ctx, rb, width, x, y + row, dest); + dest += rowLength * pixelSize; } + return GL_TRUE; + } + else { + /* can't do this format/type combination */ + return GL_FALSE; } } |