From 82b29819a9ede846ad5c37ff70b71d45cf72357a Mon Sep 17 00:00:00 2001
From: Brian Paul <brian.paul@tungstengraphics.com>
Date: Fri, 30 Sep 2005 03:01:11 +0000
Subject: [PATCH] minor improvements

---
 src/mesa/swrast/s_depth.c   |  2 +-
 src/mesa/swrast/s_drawpix.c |  8 ++++----
 src/mesa/swrast/s_readpix.c | 10 +++++-----
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/mesa/swrast/s_depth.c b/src/mesa/swrast/s_depth.c
index 4011b037e30..800e7f29fdd 100644
--- a/src/mesa/swrast/s_depth.c
+++ b/src/mesa/swrast/s_depth.c
@@ -1213,7 +1213,7 @@ _swrast_read_depth_span_float( GLcontext *ctx, struct gl_renderbuffer *rb,
    ASSERT(rb->_BaseFormat == GL_DEPTH_COMPONENT);
 
    if (y < 0 || y >= (GLint) rb->Height ||
-       x + (GLint) n <= 0 || x >= (GLint) rb->Width) {
+       x + n <= 0 || x >= (GLint) rb->Width) {
       /* span is completely outside framebuffer */
       _mesa_bzero(depth, n * sizeof(GLfloat));
       return;
diff --git a/src/mesa/swrast/s_drawpix.c b/src/mesa/swrast/s_drawpix.c
index 16404591875..7c799101d12 100644
--- a/src/mesa/swrast/s_drawpix.c
+++ b/src/mesa/swrast/s_drawpix.c
@@ -834,6 +834,8 @@ draw_depth_stencil_pixels(GLcontext *ctx, GLint x, GLint y,
                           const GLvoid *pixels)
 {
    const GLint imgX = x, imgY = y;
+   const GLboolean scaleOrBias = 
+      ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
    const GLfloat depthScale = ctx->DrawBuffer->_DepthMaxF;
    const GLuint stencilMask = ctx->Stencil.WriteMask[0];
    const GLuint stencilType = (STENCIL_BITS == 8) ? 
@@ -865,8 +867,7 @@ draw_depth_stencil_pixels(GLcontext *ctx, GLint x, GLint y,
                                GL_DEPTH_STENCIL_EXT, type, i, 0);
 
       if (ctx->Depth.Mask) {
-         if (ctx->Pixel.DepthScale == 1.0F && ctx->Pixel.DepthBias == 0.0F
-             && depthRb->DepthBits == 24) {
+         if (!scaleOrBias && depthRb->DepthBits == 24) {
             /* fast path 24-bit zbuffer */
             GLuint zValues[MAX_WIDTH];
             GLint j;
@@ -880,8 +881,7 @@ draw_depth_stencil_pixels(GLcontext *ctx, GLint x, GLint y,
             else
                depthRb->PutRow(ctx, depthRb, width, x, y + i, zValues, NULL);
          }
-         else if (ctx->Pixel.DepthScale == 1.0F && ctx->Pixel.DepthBias == 0.0F
-                  && depthRb->DepthBits == 16) {
+         else if (!scaleOrBias && depthRb->DepthBits == 16) {
             /* fast path 16-bit zbuffer */
             GLushort zValues[MAX_WIDTH];
             GLint j;
diff --git a/src/mesa/swrast/s_readpix.c b/src/mesa/swrast/s_readpix.c
index cae89724c07..3096d7a27c7 100644
--- a/src/mesa/swrast/s_readpix.c
+++ b/src/mesa/swrast/s_readpix.c
@@ -415,6 +415,8 @@ read_depth_stencil_pixels(GLcontext *ctx,
                           GLenum type, GLvoid *pixels,
                           const struct gl_pixelstore_attrib *packing )
 {
+   const GLboolean scaleOrBias = 
+      ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
    struct gl_renderbuffer *depthRb, *stencilRb;
    GLint i;
 
@@ -434,9 +436,7 @@ read_depth_stencil_pixels(GLcontext *ctx,
                                GL_DEPTH_STENCIL_EXT, type, i, 0);
 
       /* get depth values */
-      if (ctx->Pixel.DepthScale == 1.0
-          && ctx->Pixel.DepthBias == 0.0
-          && depthRb->DepthBits == 24) {
+      if (!scaleOrBias && depthRb->DepthBits == 24) {
          /* ideal case */
          ASSERT(depthRb->DataType == GL_UNSIGNED_INT);
          /* note, we've already been clipped */
@@ -447,12 +447,12 @@ read_depth_stencil_pixels(GLcontext *ctx,
          GLfloat depthVals[MAX_WIDTH];
          _swrast_read_depth_span_float(ctx, depthRb, width, x, y + i,
                                        depthVals);
-         if (ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0) {
+         if (scaleOrBias) {
             _mesa_scale_and_bias_depth(ctx, width, depthVals);
          }
          /* convert to 24-bit GLuints */
          for (j = 0; j < width; j++) {
-            zVals[j] = FLOAT_TO_UINT(depthVals[j]) >> 8;
+            zVals[j] = (GLuint) (depthVals[j] * (GLfloat) 0xffffff);
          }
       }
 
-- 
2.30.2