From d2bfdae860022b2cef2fff2de25440ba0e8f1d2b Mon Sep 17 00:00:00 2001
From: Brian <brian.paul@tungstengraphics.com>
Date: Fri, 10 Aug 2007 08:33:43 +0100
Subject: [PATCH] invert Y axis

---
 src/mesa/drivers/x11/xm_surface.c | 35 ++++++++++++++-----------------
 1 file changed, 16 insertions(+), 19 deletions(-)

diff --git a/src/mesa/drivers/x11/xm_surface.c b/src/mesa/drivers/x11/xm_surface.c
index 9d7d25667e1..1915151ba48 100644
--- a/src/mesa/drivers/x11/xm_surface.c
+++ b/src/mesa/drivers/x11/xm_surface.c
@@ -63,24 +63,28 @@ xmesa_rb(struct softpipe_surface *sps)
 }
 
 
+#define FLIP(Y) Y = xrb->St.Base.Height - (Y) - 1;
+
+
 /**
  * quad reading/writing
  * These functions are just wrappers around the existing renderbuffer
  * functions.
+ * Note that Y=0 is the top of the surface.
  */
 
 static void
 read_quad_f(struct softpipe_surface *sps, GLint x, GLint y,
             GLfloat (*rgba)[NUM_CHANNELS])
 {
-   struct xmesa_surface *xms = xmesa_surf(sps);
    struct xmesa_renderbuffer *xrb = xmesa_rb(sps);
    GLubyte temp[16];
    GLfloat *dst = (GLfloat *) rgba;
    GLuint i;
    GET_CURRENT_CONTEXT(ctx);
+   FLIP(y);
    xrb->St.Base.GetRow(ctx, &xrb->St.Base, 2, x, y,     temp);
-   xrb->St.Base.GetRow(ctx, &xrb->St.Base, 2, x, y + 1, temp + 8);
+   xrb->St.Base.GetRow(ctx, &xrb->St.Base, 2, x, y - 1, temp + 8);
    for (i = 0; i < 16; i++) {
       dst[i] = UBYTE_TO_FLOAT(temp[i]);
    }
@@ -90,14 +94,14 @@ static void
 read_quad_f_swz(struct softpipe_surface *sps, GLint x, GLint y,
                 GLfloat (*rrrr)[QUAD_SIZE])
 {
-   struct xmesa_surface *xms = xmesa_surf(sps);
    struct xmesa_renderbuffer *xrb = xmesa_rb(sps);
    GLubyte temp[16];
    GLfloat *dst = (GLfloat *) rrrr;
    GLuint i, j;
    GET_CURRENT_CONTEXT(ctx);
+   FLIP(y);
    xrb->St.Base.GetRow(ctx, &xrb->St.Base, 2, x, y,     temp);
-   xrb->St.Base.GetRow(ctx, &xrb->St.Base, 2, x, y + 1, temp + 8);
+   xrb->St.Base.GetRow(ctx, &xrb->St.Base, 2, x, y - 1, temp + 8);
    for (i = 0; i < 4; i++) {
       for (j = 0; j < 4; j++) {
          dst[j * 4 + i] = UBYTE_TO_FLOAT(temp[i * 4 + j]);
@@ -114,11 +118,12 @@ write_quad_f(struct softpipe_surface *sps, GLint x, GLint y,
    const GLfloat *src = (const GLfloat *) rgba;
    GLuint i;
    GET_CURRENT_CONTEXT(ctx);
+   FLIP(y);
    for (i = 0; i < 16; i++) {
       UNCLAMPED_FLOAT_TO_UBYTE(temp[i], src[i]);
    }
    xrb->St.Base.PutRow(ctx, &xrb->St.Base, 2, x, y,     temp,     NULL);
-   xrb->St.Base.PutRow(ctx, &xrb->St.Base, 2, x, y + 1, temp + 8, NULL);
+   xrb->St.Base.PutRow(ctx, &xrb->St.Base, 2, x, y - 1, temp + 8, NULL);
 }
 
 static void
@@ -130,13 +135,14 @@ write_quad_f_swz(struct softpipe_surface *sps, GLint x, GLint y,
    const GLfloat *src = (const GLfloat *) rrrr;
    GLuint i, j;
    GET_CURRENT_CONTEXT(ctx);
+   FLIP(y);
    for (i = 0; i < 4; i++) {
       for (j = 0; j < 4; j++) {
          UNCLAMPED_FLOAT_TO_UBYTE(temp[j * 4 + i], src[i * 4 + j]);
       }
    }
    xrb->St.Base.PutRow(ctx, &xrb->St.Base, 2, x, y,     temp,     NULL);
-   xrb->St.Base.PutRow(ctx, &xrb->St.Base, 2, x, y + 1, temp + 8, NULL);
+   xrb->St.Base.PutRow(ctx, &xrb->St.Base, 2, x, y - 1, temp + 8, NULL);
 }
 
 static void
@@ -145,8 +151,9 @@ read_quad_ub(struct softpipe_surface *sps, GLint x, GLint y,
 {
    struct xmesa_renderbuffer *xrb = xmesa_rb(sps);
    GET_CURRENT_CONTEXT(ctx);
+   FLIP(y);
    xrb->St.Base.GetRow(ctx, &xrb->St.Base, 2, x, y,     rgba);
-   xrb->St.Base.GetRow(ctx, &xrb->St.Base, 2, x, y + 1, rgba + 2);
+   xrb->St.Base.GetRow(ctx, &xrb->St.Base, 2, x, y - 1, rgba + 2);
 }
 
 static void
@@ -155,20 +162,10 @@ write_quad_ub(struct softpipe_surface *sps, GLint x, GLint y,
 {
    struct xmesa_renderbuffer *xrb = xmesa_rb(sps);
    GET_CURRENT_CONTEXT(ctx);
+   FLIP(y);
    xrb->St.Base.GetRow(ctx, &xrb->St.Base, 2, x, y,     rgba);
-   xrb->St.Base.GetRow(ctx, &xrb->St.Base, 2, x, y + 1, rgba + 2);
-}
-
-#if 0
-static void
-write_mono_row_ub(struct softpipe_surface *sps, GLuint count, GLint x, GLint y,
-                  GLubyte rgba[NUM_CHANNELS])
-{
-   struct xmesa_renderbuffer *xrb = xmesa_rb(sps);
-   GET_CURRENT_CONTEXT(ctx);
-   xrb->St.Base.PutMonoRow(ctx, &xrb->St.Base, count, x, y, rgba, NULL);
+   xrb->St.Base.GetRow(ctx, &xrb->St.Base, 2, x, y - 1, rgba + 2);
 }
-#endif
 
 
 /**
-- 
2.30.2