[Mesa-dev] [PATCH 1/5] mesa: Refactor viewport transform computation.

Brian Paul brianp at vmware.com
Wed Oct 22 14:43:37 PDT 2014


Nice clean-up.  Minor comments below.


On 10/22/2014 11:13 AM, Mathias.Froehlich at gmx.net wrote:
> From: Mathias Fröhlich <Mathias.Froehlich at gmx.net>
>
> This is for preparation of ARB_clip_control.
>
> Signed-off-by: Mathias Froehlich <Mathias.Froehlich at web.de>
> ---
>   src/mesa/drivers/dri/i915/i915_state.c    | 26 ++++++-----------
>   src/mesa/main/state.c                     |  9 +++---
>   src/mesa/main/viewport.c                  | 47 ++++++++++++++++++++-----------
>   src/mesa/main/viewport.h                  |  3 ++
>   src/mesa/math/m_matrix.c                  | 17 ++++++-----
>   src/mesa/math/m_matrix.h                  |  4 +--
>   src/mesa/state_tracker/st_atom_viewport.c | 23 +++++++--------
>   7 files changed, 68 insertions(+), 61 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i915/i915_state.c b/src/mesa/drivers/dri/i915/i915_state.c
> index f31b271..f9aecba 100644
> --- a/src/mesa/drivers/dri/i915/i915_state.c
> +++ b/src/mesa/drivers/dri/i915/i915_state.c
> @@ -34,6 +34,7 @@
>   #include "main/dd.h"
>   #include "main/state.h"
>   #include "main/stencil.h"
> +#include "main/viewport.h"
>   #include "tnl/tnl.h"
>   #include "tnl/t_context.h"
>
> @@ -401,26 +402,17 @@ void
>   intelCalcViewport(struct gl_context * ctx)
>   {
>      struct intel_context *intel = intel_context(ctx);
> +   double scale[3], translate[3];
> +
> +   _mesa_get_viewport_xform(ctx, 0, scale, translate);
>
>      if (_mesa_is_winsys_fbo(ctx->DrawBuffer)) {
> -      _math_matrix_viewport(&intel->ViewportMatrix,
> -			    ctx->ViewportArray[0].X,
> -			    ctx->DrawBuffer->Height - ctx->ViewportArray[0].Y,
> -			    ctx->ViewportArray[0].Width,
> -			    -ctx->ViewportArray[0].Height,
> -			    ctx->ViewportArray[0].Near,
> -			    ctx->ViewportArray[0].Far,
> -			    1.0);
> -   } else {
> -      _math_matrix_viewport(&intel->ViewportMatrix,
> -			    ctx->ViewportArray[0].X,
> -			    ctx->ViewportArray[0].Y,
> -			    ctx->ViewportArray[0].Width,
> -			    ctx->ViewportArray[0].Height,
> -			    ctx->ViewportArray[0].Near,
> -			    ctx->ViewportArray[0].Far,
> -			    1.0);
> +      scale[1] = -scale[1];
> +      translate[1] = ctx->DrawBuffer->Height - translate[1];
>      }
> +
> +   _math_matrix_viewport(&intel->ViewportMatrix,
> +                         scale, translate, 1.0);
>   }
>
>
> diff --git a/src/mesa/main/state.c b/src/mesa/main/state.c
> index 80287c4..3dbbfaa 100644
> --- a/src/mesa/main/state.c
> +++ b/src/mesa/main/state.c
> @@ -51,6 +51,7 @@
>   #include "texobj.h"
>   #include "texstate.h"
>   #include "varray.h"
> +#include "viewport.h"
>   #include "blend.h"
>
>
> @@ -281,11 +282,11 @@ update_viewport_matrix(struct gl_context *ctx)
>       * NOTE: RasterPos uses this.
>       */
>      for (i = 0; i < ctx->Const.MaxViewports; i++) {
> +      double scale[3], translate[3];
> +
> +      _mesa_get_viewport_xform(ctx, i, scale, translate);
>         _math_matrix_viewport(&ctx->ViewportArray[i]._WindowMap,
> -                            ctx->ViewportArray[i].X, ctx->ViewportArray[i].Y,
> -                            ctx->ViewportArray[i].Width, ctx->ViewportArray[i].Height,
> -                            ctx->ViewportArray[i].Near, ctx->ViewportArray[i].Far,
> -                            depthMax);
> +                            scale, translate, depthMax);
>      }
>   }
>
> diff --git a/src/mesa/main/viewport.c b/src/mesa/main/viewport.c
> index 222ae30..89766cf 100644
> --- a/src/mesa/main/viewport.c
> +++ b/src/mesa/main/viewport.c
> @@ -39,6 +39,8 @@ set_viewport_no_notify(struct gl_context *ctx, unsigned idx,
>                          GLfloat x, GLfloat y,
>                          GLfloat width, GLfloat height)
>   {
> +   double scale[3], translate[3];
> +
>      /* clamp width and height to the implementation dependent range */
>      width  = MIN2(width, (GLfloat) ctx->Const.MaxViewportWidth);
>      height = MIN2(height, (GLfloat) ctx->Const.MaxViewportHeight);
> @@ -75,14 +77,9 @@ set_viewport_no_notify(struct gl_context *ctx, unsigned idx,
>       * the WindowMap matrix being up to date in the driver's Viewport
>       * and DepthRange functions.
>       */
> +   _mesa_get_viewport_xform(ctx, idx, scale, translate);
>      _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
> -                         ctx->ViewportArray[idx].X,
> -                         ctx->ViewportArray[idx].Y,
> -                         ctx->ViewportArray[idx].Width,
> -                         ctx->ViewportArray[idx].Height,
> -                         ctx->ViewportArray[idx].Near,
> -                         ctx->ViewportArray[idx].Far,
> -                         ctx->DrawBuffer->_DepthMaxF);
> +                         scale, translate, ctx->DrawBuffer->_DepthMaxF);
>   #endif
>   }
>
> @@ -248,6 +245,8 @@ static void
>   set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
>                             GLclampd nearval, GLclampd farval)
>   {
> +   double scale[3], translate[3];
> +
>      if (ctx->ViewportArray[idx].Near == nearval &&
>          ctx->ViewportArray[idx].Far == farval)
>         return;
> @@ -261,14 +260,9 @@ set_depth_range_no_notify(struct gl_context *ctx, unsigned idx,
>       * the WindowMap matrix being up to date in the driver's Viewport
>       * and DepthRange functions.
>       */
> +   _mesa_get_viewport_xform(ctx, idx, scale, translate);
>      _math_matrix_viewport(&ctx->ViewportArray[idx]._WindowMap,
> -                         ctx->ViewportArray[idx].X,
> -                         ctx->ViewportArray[idx].Y,
> -                         ctx->ViewportArray[idx].Width,
> -                         ctx->ViewportArray[idx].Height,
> -                         ctx->ViewportArray[idx].Near,
> -                         ctx->ViewportArray[idx].Far,
> -                         ctx->DrawBuffer->_DepthMaxF);
> +                         scale, translate, ctx->DrawBuffer->_DepthMaxF);
>   #endif
>   }
>
> @@ -400,6 +394,8 @@ void _mesa_init_viewport(struct gl_context *ctx)
>       * so just initialize all of them.
>       */
>      for (i = 0; i < MAX_VIEWPORTS; i++) {
> +      double scale[3], translate[3];
> +
>         /* Viewport group */
>         ctx->ViewportArray[i].X = 0;
>         ctx->ViewportArray[i].Y = 0;
> @@ -409,8 +405,9 @@ void _mesa_init_viewport(struct gl_context *ctx)
>         ctx->ViewportArray[i].Far = 1.0;
>         _math_matrix_ctr(&ctx->ViewportArray[i]._WindowMap);
>
> -      _math_matrix_viewport(&ctx->ViewportArray[i]._WindowMap, 0, 0, 0, 0,
> -                            0.0F, 1.0F, depthMax);
> +      _mesa_get_viewport_xform(ctx, i, scale, translate);
> +      _math_matrix_viewport(&ctx->ViewportArray[i]._WindowMap,
> +                            scale, translate, depthMax);
>      }
>   }
>
> @@ -427,3 +424,21 @@ void _mesa_free_viewport_data(struct gl_context *ctx)
>         _math_matrix_dtr(&ctx->ViewportArray[i]._WindowMap);
>   }
>


There should probably be a comment on this new function to explain what 
it's doing.


> +void
> +_mesa_get_viewport_xform(struct gl_context *ctx, unsigned i,
> +                         double scale[3], double translate[3])
> +{
> +   double x = ctx->ViewportArray[i].X;
> +   double y = ctx->ViewportArray[i].Y;
> +   double half_width = 0.5*ctx->ViewportArray[i].Width;
> +   double half_height = 0.5*ctx->ViewportArray[i].Height;
> +   double n = ctx->ViewportArray[i].Near;
> +   double f = ctx->ViewportArray[i].Far;
> +
> +   scale[0] = half_width;
> +   translate[0] = half_width + x;
> +   scale[1] = half_height;
> +   translate[1] = half_height + y;
> +   scale[2] = 0.5*(f - n);
> +   translate[2] = 0.5*(n + f);
> +}
> diff --git a/src/mesa/main/viewport.h b/src/mesa/main/viewport.h
> index f2311c0..514ff10 100644
> --- a/src/mesa/main/viewport.h
> +++ b/src/mesa/main/viewport.h
> @@ -71,5 +71,8 @@ _mesa_init_viewport(struct gl_context *ctx);
>   extern void
>   _mesa_free_viewport_data(struct gl_context *ctx);
>
> +extern void
> +_mesa_get_viewport_xform(struct gl_context *ctx, unsigned i,
> +                         double scale[3], double translate[3]);
>
>   #endif
> diff --git a/src/mesa/math/m_matrix.c b/src/mesa/math/m_matrix.c
> index e512e45..9c9310d 100644
> --- a/src/mesa/math/m_matrix.c
> +++ b/src/mesa/math/m_matrix.c
> @@ -1110,16 +1110,15 @@ _math_matrix_translate( GLmatrix *mat, GLfloat x, GLfloat y, GLfloat z )
>    * Transforms Normalized Device Coords to window/Z values.
>    */
>   void
> -_math_matrix_viewport(GLmatrix *m, GLfloat x, GLfloat y,
> -                      GLfloat width, GLfloat height,
> -                      GLdouble zNear, GLdouble zFar, GLdouble depthMax)

Might be good to update the comments on this function too.


> +_math_matrix_viewport(GLmatrix *m, const double scale[3],
> +                      const double translate[3], double depthMax)
>   {
> -   m->m[MAT_SX] = width / 2.0F;
> -   m->m[MAT_TX] = m->m[MAT_SX] + x;
> -   m->m[MAT_SY] = height / 2.0F;
> -   m->m[MAT_TY] = m->m[MAT_SY] + y;
> -   m->m[MAT_SZ] = (GLfloat) (depthMax * ((zFar - zNear) / 2.0));
> -   m->m[MAT_TZ] = (GLfloat) (depthMax * ((zFar - zNear) / 2.0 + zNear));
> +   m->m[MAT_SX] = scale[0];
> +   m->m[MAT_TX] = translate[0];
> +   m->m[MAT_SY] = scale[1];
> +   m->m[MAT_TY] = translate[1];
> +   m->m[MAT_SZ] = depthMax*scale[2];
> +   m->m[MAT_TZ] = depthMax*translate[2];
>      m->flags = MAT_FLAG_GENERAL_SCALE | MAT_FLAG_TRANSLATION;
>      m->type = MATRIX_3D_NO_ROT;
>   }
> diff --git a/src/mesa/math/m_matrix.h b/src/mesa/math/m_matrix.h
> index dddce70..778d716 100644
> --- a/src/mesa/math/m_matrix.h
> +++ b/src/mesa/math/m_matrix.h
> @@ -122,8 +122,8 @@ _math_matrix_frustum( GLmatrix *mat,
>   		      GLfloat nearval, GLfloat farval );
>
>   extern void
> -_math_matrix_viewport(GLmatrix *m, GLfloat x, GLfloat y, GLfloat width, GLfloat height,
> -                      GLdouble zNear, GLdouble zFar, GLdouble depthMax);
> +_math_matrix_viewport( GLmatrix *m, const double scale[3],
> +                       const double translate[3], double depthMax );
>
>   extern void
>   _math_matrix_set_identity( GLmatrix *dest );
> diff --git a/src/mesa/state_tracker/st_atom_viewport.c b/src/mesa/state_tracker/st_atom_viewport.c
> index 7584f9b..5b99208 100644
> --- a/src/mesa/state_tracker/st_atom_viewport.c
> +++ b/src/mesa/state_tracker/st_atom_viewport.c
> @@ -27,6 +27,7 @@
>
>
>   #include "main/context.h"
> +#include "main/viewport.h"
>   #include "st_context.h"
>   #include "st_atom.h"
>   #include "pipe/p_context.h"
> @@ -63,21 +64,17 @@ update_viewport( struct st_context *st )
>       */
>      for (i = 0; i < ctx->Const.MaxViewports; i++)
>      {
> -      GLfloat x = ctx->ViewportArray[i].X;
> -      GLfloat y = ctx->ViewportArray[i].Y;
> -      GLfloat z = ctx->ViewportArray[i].Near;
> -      GLfloat half_width = ctx->ViewportArray[i].Width * 0.5f;
> -      GLfloat half_height = ctx->ViewportArray[i].Height * 0.5f;
> -      GLfloat half_depth = (GLfloat)(ctx->ViewportArray[i].Far - ctx->ViewportArray[i].Near) * 0.5f;
> -
> -      st->state.viewport[i].scale[0] = half_width;
> -      st->state.viewport[i].scale[1] = half_height * yScale;
> -      st->state.viewport[i].scale[2] = half_depth;
> +      double scale[3], translate[3];
> +      _mesa_get_viewport_xform(ctx, i, scale, translate);
> +
> +      st->state.viewport[i].scale[0] = scale[0];
> +      st->state.viewport[i].scale[1] = scale[1] * yScale;
> +      st->state.viewport[i].scale[2] = scale[2];
>         st->state.viewport[i].scale[3] = 1.0;
>
> -      st->state.viewport[i].translate[0] = half_width + x;
> -      st->state.viewport[i].translate[1] = (half_height + y) * yScale + yBias;
> -      st->state.viewport[i].translate[2] = half_depth + z;
> +      st->state.viewport[i].translate[0] = translate[0];
> +      st->state.viewport[i].translate[1] = translate[1] * yScale + yBias;
> +      st->state.viewport[i].translate[2] = translate[2];
>         st->state.viewport[i].translate[3] = 0.0;
>      }
>
>



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