From b5b128b26841e7f947edd8f0cbcc91a530d6bb8f Mon Sep 17 00:00:00 2001
From: Brian Paul <brianp@vmware.com>
Date: Fri, 5 Mar 2010 12:38:05 -0700
Subject: [PATCH] softpipe: implement PIPE_TEX_WRAP_CLAMP_TO_EDGE for unorm
 texture sampling

CLAMP_TO_BORDER and CLAMP_TO_EDGE were doing the same thing.
---
 src/gallium/drivers/softpipe/sp_tex_sample.c | 49 +++++++++++++++++---
 1 file changed, 43 insertions(+), 6 deletions(-)

diff --git a/src/gallium/drivers/softpipe/sp_tex_sample.c b/src/gallium/drivers/softpipe/sp_tex_sample.c
index b3a79732b46..ef7ccf41898 100644
--- a/src/gallium/drivers/softpipe/sp_tex_sample.c
+++ b/src/gallium/drivers/softpipe/sp_tex_sample.c
@@ -437,8 +437,7 @@ wrap_linear_mirror_clamp_to_border(const float s[4], unsigned size,
 
 
 /**
- * For RECT textures / unnormalized texcoords
- * Only a subset of wrap modes supported.
+ * PIPE_TEX_WRAP_CLAMP for nearest sampling, unnormalized coords.
  */
 static void
 wrap_nearest_unorm_clamp(const float s[4], unsigned size, int icoord[4])
@@ -452,11 +451,25 @@ wrap_nearest_unorm_clamp(const float s[4], unsigned size, int icoord[4])
 
 
 /**
- * Handles clamp_to_edge and clamp_to_border:
+ * PIPE_TEX_WRAP_CLAMP_TO_BORDER for nearest sampling, unnormalized coords.
  */
 static void
 wrap_nearest_unorm_clamp_to_border(const float s[4], unsigned size,
                                    int icoord[4])
+{
+   uint ch;
+   for (ch = 0; ch < 4; ch++) {
+      icoord[ch]= util_ifloor( CLAMP(s[ch], -0.5F, (float) size + 0.5F) );
+   }
+}
+
+
+/**
+ * PIPE_TEX_WRAP_CLAMP_TO_EDGE for nearest sampling, unnormalized coords.
+ */
+static void
+wrap_nearest_unorm_clamp_to_edge(const float s[4], unsigned size,
+                                 int icoord[4])
 {
    uint ch;
    for (ch = 0; ch < 4; ch++) {
@@ -466,8 +479,7 @@ wrap_nearest_unorm_clamp_to_border(const float s[4], unsigned size,
 
 
 /**
- * For RECT textures / unnormalized texcoords.
- * Only a subset of wrap modes supported.
+ * PIPE_TEX_WRAP_CLAMP for linear sampling, unnormalized coords.
  */
 static void
 wrap_linear_unorm_clamp(const float s[4], unsigned size,
@@ -484,13 +496,36 @@ wrap_linear_unorm_clamp(const float s[4], unsigned size,
 }
 
 
+/**
+ * PIPE_TEX_WRAP_CLAMP_TO_BORDER for linear sampling, unnormalized coords.
+ */
 static void
 wrap_linear_unorm_clamp_to_border(const float s[4], unsigned size,
                                   int icoord0[4], int icoord1[4], float w[4])
 {
    uint ch;
    for (ch = 0; ch < 4; ch++) {
-      float u = CLAMP(s[ch], 0.5F, (float) size - 0.5F);
+      float u = CLAMP(s[ch], -0.5F, (float) size + 0.5F);
+      u -= 0.5F;
+      icoord0[ch] = util_ifloor(u);
+      icoord1[ch] = icoord0[ch] + 1;
+      if (icoord1[ch] > (int) size - 1)
+         icoord1[ch] = size - 1;
+      w[ch] = frac(u);
+   }
+}
+
+
+/**
+ * PIPE_TEX_WRAP_CLAMP_TO_EDGE for linear sampling, unnormalized coords.
+ */
+static void
+wrap_linear_unorm_clamp_to_edge(const float s[4], unsigned size,
+                                int icoord0[4], int icoord1[4], float w[4])
+{
+   uint ch;
+   for (ch = 0; ch < 4; ch++) {
+      float u = CLAMP(s[ch], +0.5F, (float) size - 0.5F);
       u -= 0.5F;
       icoord0[ch] = util_ifloor(u);
       icoord1[ch] = icoord0[ch] + 1;
@@ -1707,6 +1742,7 @@ get_nearest_unorm_wrap(unsigned mode)
    case PIPE_TEX_WRAP_CLAMP:
       return wrap_nearest_unorm_clamp;
    case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
+      return wrap_nearest_unorm_clamp_to_edge;
    case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
       return wrap_nearest_unorm_clamp_to_border;
    default:
@@ -1750,6 +1786,7 @@ get_linear_unorm_wrap(unsigned mode)
    case PIPE_TEX_WRAP_CLAMP:
       return wrap_linear_unorm_clamp;
    case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
+      return wrap_linear_unorm_clamp_to_edge;
    case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
       return wrap_linear_unorm_clamp_to_border;
    default: