diff options
author | Brian Paul <[email protected]> | 2006-05-06 22:30:33 +0000 |
---|---|---|
committer | Brian Paul <[email protected]> | 2006-05-06 22:30:33 +0000 |
commit | 0c7cbf0a7cbba93e4bcb2f0fdd0a7ea2ef4ebc94 (patch) | |
tree | 5c362c29f4d21cb9783c1d4f19015f043052163b /src/mesa/swrast | |
parent | efbf170cfbb0ad8ad8a480a0be581b0908b53138 (diff) |
Check for overflow when converting floating pt Z values to 32-bit GLuint.
Diffstat (limited to 'src/mesa/swrast')
-rw-r--r-- | src/mesa/swrast/s_copypix.c | 47 |
1 files changed, 39 insertions, 8 deletions
diff --git a/src/mesa/swrast/s_copypix.c b/src/mesa/swrast/s_copypix.c index 842b8d20c3b..88fd445132b 100644 --- a/src/mesa/swrast/s_copypix.c +++ b/src/mesa/swrast/s_copypix.c @@ -1,8 +1,8 @@ /* * Mesa 3-D graphics library - * Version: 6.5 + * Version: 6.5.1 * - * Copyright (C) 1999-2005 Brian Paul All Rights Reserved. + * Copyright (C) 1999-2006 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"), @@ -478,6 +478,41 @@ copy_ci_pixels( GLcontext *ctx, GLint srcx, GLint srcy, } +/** + * Convert floating point Z values to integer Z values with pixel transfer's + * Z scale and bias. + */ +static void +scale_and_bias_z(GLcontext *ctx, GLuint width, + const GLfloat depth[], GLuint z[]) +{ + const GLuint depthMax = ctx->DrawBuffer->_DepthMax; + GLuint i; + + if (depthMax <= 0xffffff && + ctx->Pixel.DepthScale == 1.0 && + ctx->Pixel.DepthBias == 0.0) { + /* no scale or bias and no clamping and no worry of overflow */ + const GLfloat depthMaxF = ctx->DrawBuffer->_DepthMaxF; + for (i = 0; i < width; i++) { + z[i] = (GLuint) (depth[i] * depthMaxF); + } + } + else { + /* need to be careful with overflow */ + const GLdouble depthMaxF = ctx->DrawBuffer->_DepthMaxF; + for (i = 0; i < width; i++) { + GLdouble d = depth[i] * ctx->Pixel.DepthScale + ctx->Pixel.DepthBias; + d = CLAMP(d, 0.0, 1.0) * depthMaxF; + if (d >= depthMaxF) + z[i] = depthMax; + else + z[i] = (GLuint) d; + } + } +} + + /* * TODO: Optimize!!!! @@ -490,10 +525,9 @@ copy_depth_pixels( GLcontext *ctx, GLint srcx, GLint srcy, SWcontext *swrast = SWRAST_CONTEXT(ctx); struct gl_framebuffer *fb = ctx->ReadBuffer; struct gl_renderbuffer *readRb = fb->_DepthBuffer; - const GLfloat depthMax = fb->_DepthMaxF; GLfloat *p, *tmpImage; GLint sy, dy, stepy; - GLint i, j; + GLint j; const GLboolean zoom = ctx->Pixel.ZoomX != 1.0F || ctx->Pixel.ZoomY != 1.0F; GLint overlapping; struct sw_span span; @@ -562,10 +596,7 @@ copy_depth_pixels( GLcontext *ctx, GLint srcx, GLint srcy, } /* apply scale and bias */ - for (i = 0; i < width; i++) { - GLfloat d = depth[i] * ctx->Pixel.DepthScale + ctx->Pixel.DepthBias; - span.array->z[i] = (GLuint) (CLAMP(d, 0.0F, 1.0F) * depthMax); - } + scale_and_bias_z(ctx, width, depth, span.array->z); /* write depth values */ span.x = destx; |