1 files changed, 32 insertions, 39 deletions

diff --git a/mesalib/src/mesa/swrast/s_blit.c b/mesalib/src/mesa/swrast/s_blit.c
index 3a4e7eec0..82fa43f1c 100644
--- a/mesalib/src/mesa/swrast/s_blit.c
+++ b/mesalib/src/mesa/swrast/s_blit.c
@@ -188,29 +188,6 @@ blit_nearest(struct gl_context *ctx,
       return;
    }
 
-   /* choose row resampler */
-   switch (pixelSize) {
-   case 1:
-      resampleRow = resample_row_1;
-      break;
-   case 2:
-      resampleRow = resample_row_2;
-      break;
-   case 4:
-      resampleRow = resample_row_4;
-      break;
-   case 8:
-      resampleRow = resample_row_8;
-      break;
-   case 16:
-      resampleRow = resample_row_16;
-      break;
-   default:
-      _mesa_problem(ctx, "unexpected pixel size (%d) in blit_nearest",
-                    pixelSize);
-      return;
-   }
-
    /* Blit to all the draw buffers */
    for (i = 0; i < numDrawBuffers; i++) {
       if (buffer == GL_COLOR_BUFFER_BIT) {
@@ -232,6 +209,29 @@ blit_nearest(struct gl_context *ctx,
          }
       }
 
+      /* choose row resampler */
+      switch (pixelSize) {
+      case 1:
+         resampleRow = resample_row_1;
+         break;
+      case 2:
+         resampleRow = resample_row_2;
+         break;
+      case 4:
+         resampleRow = resample_row_4;
+         break;
+      case 8:
+         resampleRow = resample_row_8;
+         break;
+      case 16:
+         resampleRow = resample_row_16;
+         break;
+      default:
+         _mesa_problem(ctx, "unexpected pixel size (%d) in blit_nearest",
+                       pixelSize);
+         return;
+      }
+
       if ((readRb == drawRb) ||
           (readAtt->Texture && drawAtt->Texture &&
            (readAtt->Texture == drawAtt->Texture))) {
@@ -304,7 +304,8 @@ blit_nearest(struct gl_context *ctx,
       }
 
       for (dstRow = 0; dstRow < dstHeight; dstRow++) {
-         GLint srcRow = (dstRow * srcHeight) / dstHeight;
+         GLfloat srcRowF = (dstRow + 0.5F) / dstHeight * srcHeight - 0.5F;
+         GLint srcRow = IROUND(srcRowF);
          GLubyte *dstRowStart = dstMap + dstRowStride * dstRow;
 
          ASSERT(srcRow >= 0);
@@ -347,7 +348,7 @@ blit_nearest(struct gl_context *ctx,
          /* store pixel row in destination */
          switch (mode) {
          case DIRECT:
-            memcpy(dstRowStart, dstBuffer, pixelSize * srcWidth);
+            memcpy(dstRowStart, dstBuffer, pixelSize * dstWidth);
             break;
          case UNPACK_RGBA_FLOAT:
             _mesa_pack_float_rgba_row(drawRb->Format, dstWidth, dstBuffer,
@@ -404,17 +405,15 @@ resample_linear_row_ub(GLint srcWidth, GLint dstWidth,
    const GLubyte (*srcColor0)[4] = (const GLubyte (*)[4]) srcBuffer0;
    const GLubyte (*srcColor1)[4] = (const GLubyte (*)[4]) srcBuffer1;
    GLubyte (*dstColor)[4] = (GLubyte (*)[4]) dstBuffer;
-   const GLfloat dstWidthF = (GLfloat) dstWidth;
    GLint dstCol;
 
    for (dstCol = 0; dstCol < dstWidth; dstCol++) {
-      const GLfloat srcCol = (dstCol * srcWidth) / dstWidthF;
-      GLint srcCol0 = IFLOOR(srcCol);
+      const GLfloat srcCol = (dstCol + 0.5F) / dstWidth * srcWidth - 0.5F;
+      GLint srcCol0 = MAX2(0, IFLOOR(srcCol));
       GLint srcCol1 = srcCol0 + 1;
       GLfloat colWeight = srcCol - srcCol0; /* fractional part of srcCol */
       GLfloat red, green, blue, alpha;
 
-      ASSERT(srcCol0 >= 0);
       ASSERT(srcCol0 < srcWidth);
       ASSERT(srcCol1 <= srcWidth);
 
@@ -461,17 +460,15 @@ resample_linear_row_float(GLint srcWidth, GLint dstWidth,
    const GLfloat (*srcColor0)[4] = (const GLfloat (*)[4]) srcBuffer0;
    const GLfloat (*srcColor1)[4] = (const GLfloat (*)[4]) srcBuffer1;
    GLfloat (*dstColor)[4] = (GLfloat (*)[4]) dstBuffer;
-   const GLfloat dstWidthF = (GLfloat) dstWidth;
    GLint dstCol;
 
    for (dstCol = 0; dstCol < dstWidth; dstCol++) {
-      const GLfloat srcCol = (dstCol * srcWidth) / dstWidthF;
-      GLint srcCol0 = IFLOOR(srcCol);
+      const GLfloat srcCol = (dstCol + 0.5F) / dstWidth * srcWidth - 0.5F;
+      GLint srcCol0 = MAX2(0, IFLOOR(srcCol));
       GLint srcCol1 = srcCol0 + 1;
       GLfloat colWeight = srcCol - srcCol0; /* fractional part of srcCol */
       GLfloat red, green, blue, alpha;
 
-      ASSERT(srcCol0 >= 0);
       ASSERT(srcCol0 < srcWidth);
       ASSERT(srcCol1 <= srcWidth);
 
@@ -526,7 +523,6 @@ blit_linear(struct gl_context *ctx,
    const GLint dstWidth = ABS(dstX1 - dstX0);
    const GLint srcHeight = ABS(srcY1 - srcY0);
    const GLint dstHeight = ABS(dstY1 - dstY0);
-   const GLfloat dstHeightF = (GLfloat) dstHeight;
 
    const GLint srcXpos = MIN2(srcX0, srcX1);
    const GLint srcYpos = MIN2(srcY0, srcY1);
@@ -654,14 +650,11 @@ blit_linear(struct gl_context *ctx,
 
       for (dstRow = 0; dstRow < dstHeight; dstRow++) {
          const GLint dstY = dstYpos + dstRow;
-         const GLfloat srcRow = (dstRow * srcHeight) / dstHeightF;
-         GLint srcRow0 = IFLOOR(srcRow);
+         GLfloat srcRow = (dstRow + 0.5F) / dstHeight * srcHeight - 0.5F;
+         GLint srcRow0 = MAX2(0, IFLOOR(srcRow));
          GLint srcRow1 = srcRow0 + 1;
          GLfloat rowWeight = srcRow - srcRow0; /* fractional part of srcRow */
 
-         ASSERT(srcRow >= 0);
-         ASSERT(srcRow < srcHeight);
-
          if (srcRow1 == srcHeight) {
             /* last row fudge */
             srcRow1 = srcRow0;