From a94955843059af787ca5d289a87e2f35a869437a Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Mon, 24 May 2010 17:21:30 -0400 Subject: meta: Convert Z value from normalized to object-space in meta code Convert Z from a normalized value in the range [0, 1] to an object-space Z coordinate in [-1, +1] so that drawing at the new Z position with the default/identity ortho projection results in the original Z value. Used by the meta-Clear, Draw/CopyPixels and Bitmap functions where the Z value comes from the clear value or raster position. Fixes piglit tests fdo23670-depth_test, quad-invariance and glsl-orangebook-ch06-bump as well as oglc zbfunc.c. https://bugs.freedesktop.org/show_bug.cgi?id=23670 --- src/mesa/drivers/common/meta.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) (limited to 'src/mesa/drivers/common') diff --git a/src/mesa/drivers/common/meta.c b/src/mesa/drivers/common/meta.c index ea9e417391..fc28685166 100644 --- a/src/mesa/drivers/common/meta.c +++ b/src/mesa/drivers/common/meta.c @@ -817,6 +817,21 @@ _mesa_meta_end(GLcontext *ctx) } +/** + * Convert Z from a normalized value in the range [0, 1] to an object-space + * Z coordinate in [-1, +1] so that drawing at the new Z position with the + * default/identity ortho projection results in the original Z value. + * Used by the meta-Clear, Draw/CopyPixels and Bitmap functions where the Z + * value comes from the clear value or raster position. + */ +static INLINE GLfloat +invert_z(GLfloat normZ) +{ + GLfloat objZ = 1.0 - 2.0 * normZ; + return objZ; +} + + /** * One-time init for a temp_texture object. * Choose tex target, compute max tex size, etc. @@ -1438,7 +1453,7 @@ _mesa_meta_Clear(GLcontext *ctx, GLbitfield buffers) const GLfloat y0 = (GLfloat) ctx->DrawBuffer->_Ymin; const GLfloat x1 = (GLfloat) ctx->DrawBuffer->_Xmax; const GLfloat y1 = (GLfloat) ctx->DrawBuffer->_Ymax; - const GLfloat z = 1.0 - 2.0 * ctx->Depth.Clear; + const GLfloat z = invert_z(ctx->Depth.Clear); GLuint i; verts[0].x = x0; @@ -1544,7 +1559,7 @@ _mesa_meta_CopyPixels(GLcontext *ctx, GLint srcX, GLint srcY, const GLfloat dstY0 = (GLfloat) dstY; const GLfloat dstX1 = dstX + width * ctx->Pixel.ZoomX; const GLfloat dstY1 = dstY + height * ctx->Pixel.ZoomY; - const GLfloat z = ctx->Current.RasterPos[2]; + const GLfloat z = invert_z(ctx->Current.RasterPos[2]); verts[0].x = dstX0; verts[0].y = dstY0; @@ -1833,7 +1848,7 @@ _mesa_meta_DrawPixels(GLcontext *ctx, const GLfloat y0 = (GLfloat) y; const GLfloat x1 = x + width * ctx->Pixel.ZoomX; const GLfloat y1 = y + height * ctx->Pixel.ZoomY; - const GLfloat z = ctx->Current.RasterPos[2]; + const GLfloat z = invert_z(ctx->Current.RasterPos[2]); verts[0].x = x0; verts[0].y = y0; @@ -2036,7 +2051,7 @@ _mesa_meta_Bitmap(GLcontext *ctx, const GLfloat y0 = (GLfloat) y; const GLfloat x1 = (GLfloat) (x + width); const GLfloat y1 = (GLfloat) (y + height); - const GLfloat z = ctx->Current.RasterPos[2]; + const GLfloat z = invert_z(ctx->Current.RasterPos[2]); GLuint i; verts[0].x = x0; -- cgit v1.2.3