pixman mesa git update 16 Feb 2011

1 files changed, 563 insertions, 559 deletions

diff --git a/mesalib/src/mesa/state_tracker/st_cb_clear.c b/mesalib/src/mesa/state_tracker/st_cb_clear.c
index 3e27be271..d2e0cd73c 100644
--- a/mesalib/src/mesa/state_tracker/st_cb_clear.c
+++ b/mesalib/src/mesa/state_tracker/st_cb_clear.c
@@ -1,559 +1,563 @@
-/**************************************************************************

- * 

- * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.

- * All Rights Reserved.

- * Copyright 2009 VMware, Inc.  All Rights Reserved.

- * 

- * Permission is hereby granted, free of charge, to any person obtaining a

- * copy of this software and associated documentation files (the

- * "Software"), to deal in the Software without restriction, including

- * without limitation the rights to use, copy, modify, merge, publish,

- * distribute, sub license, and/or sell copies of the Software, and to

- * permit persons to whom the Software is furnished to do so, subject to

- * the following conditions:

- * 

- * The above copyright notice and this permission notice (including the

- * next paragraph) shall be included in all copies or substantial portions

- * of the Software.

- * 

- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

- * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.

- * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR

- * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,

- * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE

- * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

- * 

- **************************************************************************/

-

- /*

-  * Authors:

-  *   Keith Whitwell <keith@tungstengraphics.com>

-  *   Brian Paul

-  *   Michel Dänzer

-  */

-

-#include "main/glheader.h"

-#include "main/formats.h"

-#include "main/macros.h"

-#include "program/prog_instruction.h"

-#include "st_context.h"

-#include "st_atom.h"

-#include "st_cb_accum.h"

-#include "st_cb_clear.h"

-#include "st_cb_fbo.h"

-#include "st_program.h"

-

-#include "pipe/p_context.h"

-#include "pipe/p_shader_tokens.h"

-#include "pipe/p_state.h"

-#include "pipe/p_defines.h"

-#include "util/u_format.h"

-#include "util/u_inlines.h"

-#include "util/u_simple_shaders.h"

-#include "util/u_draw_quad.h"

-

-#include "cso_cache/cso_context.h"

-

-

-/**

- * Do per-context initialization for glClear.

- */

-void

-st_init_clear(struct st_context *st)

-{

-   struct pipe_context *pipe = st->pipe;

-   struct pipe_screen *pscreen = st->pipe->screen;

-

-   memset(&st->clear, 0, sizeof(st->clear));

-

-   st->clear.raster.gl_rasterization_rules = 1;

-   st->clear.enable_ds_separate = pscreen->get_param(pscreen, PIPE_CAP_DEPTHSTENCIL_CLEAR_SEPARATE);

-

-   /* fragment shader state: color pass-through program */

-   st->clear.fs = util_make_fragment_passthrough_shader(pipe);

-

-   /* vertex shader state: color/position pass-through */

-   {

-      const uint semantic_names[] = { TGSI_SEMANTIC_POSITION,

-                                      TGSI_SEMANTIC_COLOR };

-      const uint semantic_indexes[] = { 0, 0 };

-      st->clear.vs = util_make_vertex_passthrough_shader(pipe, 2,

-                                                         semantic_names,

-                                                         semantic_indexes);

-   }

-}

-

-

-/**

- * Free per-context state for glClear.

- */

-void

-st_destroy_clear(struct st_context *st)

-{

-   if (st->clear.fs) {

-      cso_delete_fragment_shader(st->cso_context, st->clear.fs);

-      st->clear.fs = NULL;

-   }

-   if (st->clear.vs) {

-      cso_delete_vertex_shader(st->cso_context, st->clear.vs);

-      st->clear.vs = NULL;

-   }

-   if (st->clear.vbuf) {

-      pipe_resource_reference(&st->clear.vbuf, NULL);

-      st->clear.vbuf = NULL;

-   }

-}

-

-

-/**

- * Draw a screen-aligned quadrilateral.

- * Coords are clip coords with y=0=bottom.

- */

-static void

-draw_quad(struct st_context *st,

-          float x0, float y0, float x1, float y1, GLfloat z,

-          const GLfloat color[4])

-{

-   struct pipe_context *pipe = st->pipe;

-

-   /* XXX: Need to improve buffer_write to allow NO_WAIT (as well as

-    * no_flush) updates to buffers where we know there is no conflict

-    * with previous data.  Currently using max_slots > 1 will cause

-    * synchronous rendering if the driver flushes its command buffers

-    * between one bitmap and the next.  Our flush hook below isn't

-    * sufficient to catch this as the driver doesn't tell us when it

-    * flushes its own command buffers.  Until this gets fixed, pay the

-    * price of allocating a new buffer for each bitmap cache-flush to

-    * avoid synchronous rendering.

-    */

-   const GLuint max_slots = 1; /* 1024 / sizeof(st->clear.vertices); */

-   GLuint i;

-

-   if (st->clear.vbuf_slot >= max_slots) {

-      pipe_resource_reference(&st->clear.vbuf, NULL);

-      st->clear.vbuf_slot = 0;

-   }

-

-   if (!st->clear.vbuf) {

-      st->clear.vbuf = pipe_buffer_create(pipe->screen,

-                                          PIPE_BIND_VERTEX_BUFFER,

-                                          max_slots * sizeof(st->clear.vertices));

-   }

-

-   /* positions */

-   st->clear.vertices[0][0][0] = x0;

-   st->clear.vertices[0][0][1] = y0;

-

-   st->clear.vertices[1][0][0] = x1;

-   st->clear.vertices[1][0][1] = y0;

-

-   st->clear.vertices[2][0][0] = x1;

-   st->clear.vertices[2][0][1] = y1;

-

-   st->clear.vertices[3][0][0] = x0;

-   st->clear.vertices[3][0][1] = y1;

-

-   /* same for all verts: */

-   for (i = 0; i < 4; i++) {

-      st->clear.vertices[i][0][2] = z;

-      st->clear.vertices[i][0][3] = 1.0;

-      st->clear.vertices[i][1][0] = color[0];

-      st->clear.vertices[i][1][1] = color[1];

-      st->clear.vertices[i][1][2] = color[2];

-      st->clear.vertices[i][1][3] = color[3];

-   }

-

-   /* put vertex data into vbuf */

-   pipe_buffer_write_nooverlap(st->pipe, st->clear.vbuf,

-                                           st->clear.vbuf_slot

-                                             * sizeof(st->clear.vertices),

-                                           sizeof(st->clear.vertices),

-                                           st->clear.vertices);

-

-   /* draw */

-   util_draw_vertex_buffer(pipe, 

-                           st->clear.vbuf, 

-                           st->clear.vbuf_slot * sizeof(st->clear.vertices),

-                           PIPE_PRIM_TRIANGLE_FAN,

-                           4,  /* verts */

-                           2); /* attribs/vert */

-

-   /* Increment slot */

-   st->clear.vbuf_slot++;

-}

-

-

-

-/**

- * Do glClear by drawing a quadrilateral.

- * The vertices of the quad will be computed from the

- * ctx->DrawBuffer->_X/Ymin/max fields.

- */

-static void

-clear_with_quad(struct gl_context *ctx,

-                GLboolean color, GLboolean depth, GLboolean stencil)

-{

-   struct st_context *st = st_context(ctx);

-   const struct gl_framebuffer *fb = ctx->DrawBuffer;

-   const GLfloat fb_width = (GLfloat) fb->Width;

-   const GLfloat fb_height = (GLfloat) fb->Height;

-   const GLfloat x0 = (GLfloat) ctx->DrawBuffer->_Xmin / fb_width * 2.0f - 1.0f;

-   const GLfloat x1 = (GLfloat) ctx->DrawBuffer->_Xmax / fb_width * 2.0f - 1.0f;

-   const GLfloat y0 = (GLfloat) ctx->DrawBuffer->_Ymin / fb_height * 2.0f - 1.0f;

-   const GLfloat y1 = (GLfloat) ctx->DrawBuffer->_Ymax / fb_height * 2.0f - 1.0f;

-

-   /*

-   printf("%s %s%s%s %f,%f %f,%f\n", __FUNCTION__, 

-	  color ? "color, " : "",

-	  depth ? "depth, " : "",

-	  stencil ? "stencil" : "",

-	  x0, y0,

-	  x1, y1);

-   */

-

-   cso_save_blend(st->cso_context);

-   cso_save_stencil_ref(st->cso_context);

-   cso_save_depth_stencil_alpha(st->cso_context);

-   cso_save_rasterizer(st->cso_context);

-   cso_save_viewport(st->cso_context);

-   cso_save_clip(st->cso_context);

-   cso_save_fragment_shader(st->cso_context);

-   cso_save_vertex_shader(st->cso_context);

-   cso_save_vertex_elements(st->cso_context);

-

-   /* blend state: RGBA masking */

-   {

-      struct pipe_blend_state blend;

-      memset(&blend, 0, sizeof(blend));

-      blend.rt[0].rgb_src_factor = PIPE_BLENDFACTOR_ONE;

-      blend.rt[0].alpha_src_factor = PIPE_BLENDFACTOR_ONE;

-      blend.rt[0].rgb_dst_factor = PIPE_BLENDFACTOR_ZERO;

-      blend.rt[0].alpha_dst_factor = PIPE_BLENDFACTOR_ZERO;

-      if (color) {

-         if (ctx->Color.ColorMask[0][0])

-            blend.rt[0].colormask |= PIPE_MASK_R;

-         if (ctx->Color.ColorMask[0][1])

-            blend.rt[0].colormask |= PIPE_MASK_G;

-         if (ctx->Color.ColorMask[0][2])

-            blend.rt[0].colormask |= PIPE_MASK_B;

-         if (ctx->Color.ColorMask[0][3])

-            blend.rt[0].colormask |= PIPE_MASK_A;

-         if (st->ctx->Color.DitherFlag)

-            blend.dither = 1;

-      }

-      cso_set_blend(st->cso_context, &blend);

-   }

-

-   /* depth_stencil state: always pass/set to ref value */

-   {

-      struct pipe_depth_stencil_alpha_state depth_stencil;

-      memset(&depth_stencil, 0, sizeof(depth_stencil));

-      if (depth) {

-         depth_stencil.depth.enabled = 1;

-         depth_stencil.depth.writemask = 1;

-         depth_stencil.depth.func = PIPE_FUNC_ALWAYS;

-      }

-

-      if (stencil) {

-         struct pipe_stencil_ref stencil_ref;

-         memset(&stencil_ref, 0, sizeof(stencil_ref));

-         depth_stencil.stencil[0].enabled = 1;

-         depth_stencil.stencil[0].func = PIPE_FUNC_ALWAYS;

-         depth_stencil.stencil[0].fail_op = PIPE_STENCIL_OP_REPLACE;

-         depth_stencil.stencil[0].zpass_op = PIPE_STENCIL_OP_REPLACE;

-         depth_stencil.stencil[0].zfail_op = PIPE_STENCIL_OP_REPLACE;

-         depth_stencil.stencil[0].valuemask = 0xff;

-         depth_stencil.stencil[0].writemask = ctx->Stencil.WriteMask[0] & 0xff;

-         stencil_ref.ref_value[0] = ctx->Stencil.Clear;

-         cso_set_stencil_ref(st->cso_context, &stencil_ref);

-      }

-

-      cso_set_depth_stencil_alpha(st->cso_context, &depth_stencil);

-   }

-

-   cso_set_vertex_elements(st->cso_context, 2, st->velems_util_draw);

-

-   cso_set_rasterizer(st->cso_context, &st->clear.raster);

-

-   /* viewport state: viewport matching window dims */

-   {

-      const GLboolean invert = (st_fb_orientation(fb) == Y_0_TOP);

-      struct pipe_viewport_state vp;

-      vp.scale[0] = 0.5f * fb_width;

-      vp.scale[1] = fb_height * (invert ? -0.5f : 0.5f);

-      vp.scale[2] = 1.0f;

-      vp.scale[3] = 1.0f;

-      vp.translate[0] = 0.5f * fb_width;

-      vp.translate[1] = 0.5f * fb_height;

-      vp.translate[2] = 0.0f;

-      vp.translate[3] = 0.0f;

-      cso_set_viewport(st->cso_context, &vp);

-   }

-

-   cso_set_clip(st->cso_context, &st->clear.clip);

-   cso_set_fragment_shader_handle(st->cso_context, st->clear.fs);

-   cso_set_vertex_shader_handle(st->cso_context, st->clear.vs);

-

-   /* draw quad matching scissor rect (XXX verify coord round-off) */

-   draw_quad(st, x0, y0, x1, y1,

-             (GLfloat) ctx->Depth.Clear, ctx->Color.ClearColor);

-

-   /* Restore pipe state */

-   cso_restore_blend(st->cso_context);

-   cso_restore_stencil_ref(st->cso_context);

-   cso_restore_depth_stencil_alpha(st->cso_context);

-   cso_restore_rasterizer(st->cso_context);

-   cso_restore_viewport(st->cso_context);

-   cso_restore_clip(st->cso_context);

-   cso_restore_fragment_shader(st->cso_context);

-   cso_restore_vertex_shader(st->cso_context);

-   cso_restore_vertex_elements(st->cso_context);

-}

-

-

-/**

- * Determine if we need to clear the depth buffer by drawing a quad.

- */

-static INLINE GLboolean

-check_clear_color_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb)

-{

-   if (ctx->Scissor.Enabled &&

-       (ctx->Scissor.X != 0 ||

-        ctx->Scissor.Y != 0 ||

-        ctx->Scissor.Width < rb->Width ||

-        ctx->Scissor.Height < rb->Height))

-      return GL_TRUE;

-

-   if (!ctx->Color.ColorMask[0][0] ||

-       !ctx->Color.ColorMask[0][1] ||

-       !ctx->Color.ColorMask[0][2] ||

-       !ctx->Color.ColorMask[0][3])

-      return GL_TRUE;

-

-   return GL_FALSE;

-}

-

-

-/**

- * Determine if we need to clear the combiend depth/stencil buffer by

- * drawing a quad.

- */

-static INLINE GLboolean

-check_clear_depth_stencil_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb)

-{

-   const GLuint stencilMax = 0xff;

-   GLboolean maskStencil

-      = (ctx->Stencil.WriteMask[0] & stencilMax) != stencilMax;

-

-   assert(rb->Format == MESA_FORMAT_S8 ||

-          rb->Format == MESA_FORMAT_Z24_S8 ||

-          rb->Format == MESA_FORMAT_S8_Z24);

-

-   if (ctx->Scissor.Enabled &&

-       (ctx->Scissor.X != 0 ||

-        ctx->Scissor.Y != 0 ||

-        ctx->Scissor.Width < rb->Width ||

-        ctx->Scissor.Height < rb->Height))

-      return GL_TRUE;

-

-   if (maskStencil)

-      return GL_TRUE;

-

-   return GL_FALSE;

-}

-

-

-/**

- * Determine if we need to clear the depth buffer by drawing a quad.

- */

-static INLINE GLboolean

-check_clear_depth_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb,

-                            boolean ds_separate)

-{

-   const struct st_renderbuffer *strb = st_renderbuffer(rb);

-   const GLboolean isDS = util_format_is_depth_and_stencil(strb->surface->format);

-

-   if (ctx->Scissor.Enabled &&

-       (ctx->Scissor.X != 0 ||

-        ctx->Scissor.Y != 0 ||

-        ctx->Scissor.Width < rb->Width ||

-        ctx->Scissor.Height < rb->Height))

-      return GL_TRUE;

-

-   if (!ds_separate && isDS && ctx->DrawBuffer->Visual.stencilBits > 0)

-      return GL_TRUE;

-

-   return GL_FALSE;

-}

-

-

-/**

- * Determine if we need to clear the stencil buffer by drawing a quad.

- */

-static INLINE GLboolean

-check_clear_stencil_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb,

-                              boolean ds_separate)

-{

-   const struct st_renderbuffer *strb = st_renderbuffer(rb);

-   const GLboolean isDS = util_format_is_depth_and_stencil(strb->surface->format);

-   const GLuint stencilMax = 0xff;

-   const GLboolean maskStencil

-      = (ctx->Stencil.WriteMask[0] & stencilMax) != stencilMax;

-

-   assert(rb->Format == MESA_FORMAT_S8 ||

-          rb->Format == MESA_FORMAT_Z24_S8 ||

-          rb->Format == MESA_FORMAT_S8_Z24);

-

-   if (maskStencil) 

-      return GL_TRUE;

-

-   if (ctx->Scissor.Enabled &&

-       (ctx->Scissor.X != 0 ||

-        ctx->Scissor.Y != 0 ||

-        ctx->Scissor.Width < rb->Width ||

-        ctx->Scissor.Height < rb->Height))

-      return GL_TRUE;

-

-   /* This is correct, but it is necessary to look at the depth clear

-    * value held in the surface when it comes time to issue the clear,

-    * rather than taking depth and stencil clear values from the

-    * current state.

-    */

-   if (!ds_separate && isDS && ctx->DrawBuffer->Visual.depthBits > 0)

-      return GL_TRUE;

-

-   return GL_FALSE;

-}

-

-

-

-/**

- * Called when we need to flush.

- */

-void

-st_flush_clear(struct st_context *st)

-{

-   /* Release vertex buffer to avoid synchronous rendering if we were

-    * to map it in the next frame.

-    */

-   pipe_resource_reference(&st->clear.vbuf, NULL);

-   st->clear.vbuf_slot = 0;

-}

- 

-

-

-/**

- * Called via ctx->Driver.Clear()

- */

-static void

-st_Clear(struct gl_context *ctx, GLbitfield mask)

-{

-   static const GLbitfield BUFFER_BITS_DS

-      = (BUFFER_BIT_DEPTH | BUFFER_BIT_STENCIL);

-   struct st_context *st = st_context(ctx);

-   struct gl_renderbuffer *depthRb

-      = ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;

-   struct gl_renderbuffer *stencilRb

-      = ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;

-   GLbitfield quad_buffers = 0x0;

-   GLbitfield clear_buffers = 0x0;

-   GLuint i;

-

-   /* This makes sure the pipe has the latest scissor, etc values */

-   st_validate_state( st );

-

-   if (mask & BUFFER_BITS_COLOR) {

-      for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) {

-         GLuint b = ctx->DrawBuffer->_ColorDrawBufferIndexes[i];

-

-         if (mask & (1 << b)) {

-            struct gl_renderbuffer *rb

-               = ctx->DrawBuffer->Attachment[b].Renderbuffer;

-            struct st_renderbuffer *strb = st_renderbuffer(rb);

-

-            if (!strb || !strb->surface)

-               continue;

-

-            if (check_clear_color_with_quad( ctx, rb ))

-               quad_buffers |= PIPE_CLEAR_COLOR;

-            else

-               clear_buffers |= PIPE_CLEAR_COLOR;

-         }

-      }

-   }

-

-   if ((mask & BUFFER_BITS_DS) == BUFFER_BITS_DS && depthRb == stencilRb) {

-      /* clearing combined depth + stencil */

-      struct st_renderbuffer *strb = st_renderbuffer(depthRb);

-

-      if (strb->surface) {

-         if (check_clear_depth_stencil_with_quad(ctx, depthRb))

-            quad_buffers |= PIPE_CLEAR_DEPTHSTENCIL;

-         else

-            clear_buffers |= PIPE_CLEAR_DEPTHSTENCIL;

-      }

-   }

-   else {

-      /* separate depth/stencil clears */

-      /* I don't think truly separate buffers are actually possible in gallium or hw? */

-      if (mask & BUFFER_BIT_DEPTH) {

-         struct st_renderbuffer *strb = st_renderbuffer(depthRb);

-

-         if (strb->surface) {

-            if (check_clear_depth_with_quad(ctx, depthRb,

-                                            st->clear.enable_ds_separate))

-               quad_buffers |= PIPE_CLEAR_DEPTH;

-            else

-               clear_buffers |= PIPE_CLEAR_DEPTH;

-         }

-      }

-      if (mask & BUFFER_BIT_STENCIL) {

-         struct st_renderbuffer *strb = st_renderbuffer(stencilRb);

-

-         if (strb->surface) {

-            if (check_clear_stencil_with_quad(ctx, stencilRb,

-                                              st->clear.enable_ds_separate))

-               quad_buffers |= PIPE_CLEAR_STENCIL;

-            else

-               clear_buffers |= PIPE_CLEAR_STENCIL;

-         }

-      }

-   }

-

-   /*

-    * If we're going to use clear_with_quad() for any reason, use it for

-    * everything possible.

-    */

-   if (quad_buffers) {

-      quad_buffers |= clear_buffers;

-      clear_with_quad(ctx,

-                      quad_buffers & PIPE_CLEAR_COLOR,

-                      quad_buffers & PIPE_CLEAR_DEPTH,

-                      quad_buffers & PIPE_CLEAR_STENCIL);

-   } else if (clear_buffers) {

-      /* driver cannot know it can clear everything if the buffer

-       * is a combined depth/stencil buffer but this wasn't actually

-       * required from the visual. Hence fix this up to avoid potential

-       * read-modify-write in the driver.

-       */

-      if ((clear_buffers & PIPE_CLEAR_DEPTHSTENCIL) &&

-          ((clear_buffers & PIPE_CLEAR_DEPTHSTENCIL) != PIPE_CLEAR_DEPTHSTENCIL) &&

-          (depthRb == stencilRb) &&

-          (ctx->DrawBuffer->Visual.depthBits == 0 ||

-           ctx->DrawBuffer->Visual.stencilBits == 0))

-         clear_buffers |= PIPE_CLEAR_DEPTHSTENCIL;

-      st->pipe->clear(st->pipe, clear_buffers, ctx->Color.ClearColor,

-                      ctx->Depth.Clear, ctx->Stencil.Clear);

-   }

-   if (mask & BUFFER_BIT_ACCUM)

-      st_clear_accum_buffer(ctx,

-                            ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer);

-}

-

-

-void

-st_init_clear_functions(struct dd_function_table *functions)

-{

-   functions->Clear = st_Clear;

-}

+/**************************************************************************
+ * 
+ * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * All Rights Reserved.
+ * Copyright 2009 VMware, Inc.  All Rights Reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * 
+ **************************************************************************/
+
+ /*
+  * Authors:
+  *   Keith Whitwell <keith@tungstengraphics.com>
+  *   Brian Paul
+  *   Michel Dänzer
+  */
+
+#include "main/glheader.h"
+#include "main/formats.h"
+#include "main/macros.h"
+#include "program/prog_instruction.h"
+#include "st_context.h"
+#include "st_atom.h"
+#include "st_cb_accum.h"
+#include "st_cb_clear.h"
+#include "st_cb_fbo.h"
+#include "st_program.h"
+
+#include "pipe/p_context.h"
+#include "pipe/p_shader_tokens.h"
+#include "pipe/p_state.h"
+#include "pipe/p_defines.h"
+#include "util/u_format.h"
+#include "util/u_inlines.h"
+#include "util/u_simple_shaders.h"
+#include "util/u_draw_quad.h"
+
+#include "cso_cache/cso_context.h"
+
+
+/**
+ * Do per-context initialization for glClear.
+ */
+void
+st_init_clear(struct st_context *st)
+{
+   struct pipe_context *pipe = st->pipe;
+   struct pipe_screen *pscreen = st->pipe->screen;
+
+   memset(&st->clear, 0, sizeof(st->clear));
+
+   st->clear.raster.gl_rasterization_rules = 1;
+   st->clear.enable_ds_separate = pscreen->get_param(pscreen, PIPE_CAP_DEPTHSTENCIL_CLEAR_SEPARATE);
+
+   /* fragment shader state: color pass-through program */
+   st->clear.fs = util_make_fragment_passthrough_shader(pipe);
+
+   /* vertex shader state: color/position pass-through */
+   {
+      const uint semantic_names[] = { TGSI_SEMANTIC_POSITION,
+                                      TGSI_SEMANTIC_COLOR };
+      const uint semantic_indexes[] = { 0, 0 };
+      st->clear.vs = util_make_vertex_passthrough_shader(pipe, 2,
+                                                         semantic_names,
+                                                         semantic_indexes);
+   }
+}
+
+
+/**
+ * Free per-context state for glClear.
+ */
+void
+st_destroy_clear(struct st_context *st)
+{
+   if (st->clear.fs) {
+      cso_delete_fragment_shader(st->cso_context, st->clear.fs);
+      st->clear.fs = NULL;
+   }
+   if (st->clear.vs) {
+      cso_delete_vertex_shader(st->cso_context, st->clear.vs);
+      st->clear.vs = NULL;
+   }
+   if (st->clear.vbuf) {
+      pipe_resource_reference(&st->clear.vbuf, NULL);
+      st->clear.vbuf = NULL;
+   }
+}
+
+
+/**
+ * Draw a screen-aligned quadrilateral.
+ * Coords are clip coords with y=0=bottom.
+ */
+static void
+draw_quad(struct st_context *st,
+          float x0, float y0, float x1, float y1, GLfloat z,
+          const GLfloat color[4])
+{
+   struct pipe_context *pipe = st->pipe;
+
+   /* XXX: Need to improve buffer_write to allow NO_WAIT (as well as
+    * no_flush) updates to buffers where we know there is no conflict
+    * with previous data.  Currently using max_slots > 1 will cause
+    * synchronous rendering if the driver flushes its command buffers
+    * between one bitmap and the next.  Our flush hook below isn't
+    * sufficient to catch this as the driver doesn't tell us when it
+    * flushes its own command buffers.  Until this gets fixed, pay the
+    * price of allocating a new buffer for each bitmap cache-flush to
+    * avoid synchronous rendering.
+    */
+   const GLuint max_slots = 1; /* 1024 / sizeof(st->clear.vertices); */
+   GLuint i;
+
+   if (st->clear.vbuf_slot >= max_slots) {
+      pipe_resource_reference(&st->clear.vbuf, NULL);
+      st->clear.vbuf_slot = 0;
+   }
+
+   if (!st->clear.vbuf) {
+      st->clear.vbuf = pipe_buffer_create(pipe->screen,
+                                          PIPE_BIND_VERTEX_BUFFER,
+                                          PIPE_USAGE_STREAM,
+                                          max_slots * sizeof(st->clear.vertices));
+   }
+
+   /* positions */
+   st->clear.vertices[0][0][0] = x0;
+   st->clear.vertices[0][0][1] = y0;
+
+   st->clear.vertices[1][0][0] = x1;
+   st->clear.vertices[1][0][1] = y0;
+
+   st->clear.vertices[2][0][0] = x1;
+   st->clear.vertices[2][0][1] = y1;
+
+   st->clear.vertices[3][0][0] = x0;
+   st->clear.vertices[3][0][1] = y1;
+
+   /* same for all verts: */
+   for (i = 0; i < 4; i++) {
+      st->clear.vertices[i][0][2] = z;
+      st->clear.vertices[i][0][3] = 1.0;
+      st->clear.vertices[i][1][0] = color[0];
+      st->clear.vertices[i][1][1] = color[1];
+      st->clear.vertices[i][1][2] = color[2];
+      st->clear.vertices[i][1][3] = color[3];
+   }
+
+   /* put vertex data into vbuf */
+   pipe_buffer_write_nooverlap(st->pipe, st->clear.vbuf,
+                                           st->clear.vbuf_slot
+                                             * sizeof(st->clear.vertices),
+                                           sizeof(st->clear.vertices),
+                                           st->clear.vertices);
+
+   /* draw */
+   util_draw_vertex_buffer(pipe,
+                           st->cso_context,
+                           st->clear.vbuf, 
+                           st->clear.vbuf_slot * sizeof(st->clear.vertices),
+                           PIPE_PRIM_TRIANGLE_FAN,
+                           4,  /* verts */
+                           2); /* attribs/vert */
+
+   /* Increment slot */
+   st->clear.vbuf_slot++;
+}
+
+
+
+/**
+ * Do glClear by drawing a quadrilateral.
+ * The vertices of the quad will be computed from the
+ * ctx->DrawBuffer->_X/Ymin/max fields.
+ */
+static void
+clear_with_quad(struct gl_context *ctx,
+                GLboolean color, GLboolean depth, GLboolean stencil)
+{
+   struct st_context *st = st_context(ctx);
+   const struct gl_framebuffer *fb = ctx->DrawBuffer;
+   const GLfloat fb_width = (GLfloat) fb->Width;
+   const GLfloat fb_height = (GLfloat) fb->Height;
+   const GLfloat x0 = (GLfloat) ctx->DrawBuffer->_Xmin / fb_width * 2.0f - 1.0f;
+   const GLfloat x1 = (GLfloat) ctx->DrawBuffer->_Xmax / fb_width * 2.0f - 1.0f;
+   const GLfloat y0 = (GLfloat) ctx->DrawBuffer->_Ymin / fb_height * 2.0f - 1.0f;
+   const GLfloat y1 = (GLfloat) ctx->DrawBuffer->_Ymax / fb_height * 2.0f - 1.0f;
+
+   /*
+   printf("%s %s%s%s %f,%f %f,%f\n", __FUNCTION__, 
+	  color ? "color, " : "",
+	  depth ? "depth, " : "",
+	  stencil ? "stencil" : "",
+	  x0, y0,
+	  x1, y1);
+   */
+
+   cso_save_blend(st->cso_context);
+   cso_save_stencil_ref(st->cso_context);
+   cso_save_depth_stencil_alpha(st->cso_context);
+   cso_save_rasterizer(st->cso_context);
+   cso_save_viewport(st->cso_context);
+   cso_save_clip(st->cso_context);
+   cso_save_fragment_shader(st->cso_context);
+   cso_save_vertex_shader(st->cso_context);
+   cso_save_vertex_elements(st->cso_context);
+   cso_save_vertex_buffers(st->cso_context);
+
+   /* blend state: RGBA masking */
+   {
+      struct pipe_blend_state blend;
+      memset(&blend, 0, sizeof(blend));
+      blend.rt[0].rgb_src_factor = PIPE_BLENDFACTOR_ONE;
+      blend.rt[0].alpha_src_factor = PIPE_BLENDFACTOR_ONE;
+      blend.rt[0].rgb_dst_factor = PIPE_BLENDFACTOR_ZERO;
+      blend.rt[0].alpha_dst_factor = PIPE_BLENDFACTOR_ZERO;
+      if (color) {
+         if (ctx->Color.ColorMask[0][0])
+            blend.rt[0].colormask |= PIPE_MASK_R;
+         if (ctx->Color.ColorMask[0][1])
+            blend.rt[0].colormask |= PIPE_MASK_G;
+         if (ctx->Color.ColorMask[0][2])
+            blend.rt[0].colormask |= PIPE_MASK_B;
+         if (ctx->Color.ColorMask[0][3])
+            blend.rt[0].colormask |= PIPE_MASK_A;
+         if (st->ctx->Color.DitherFlag)
+            blend.dither = 1;
+      }
+      cso_set_blend(st->cso_context, &blend);
+   }
+
+   /* depth_stencil state: always pass/set to ref value */
+   {
+      struct pipe_depth_stencil_alpha_state depth_stencil;
+      memset(&depth_stencil, 0, sizeof(depth_stencil));
+      if (depth) {
+         depth_stencil.depth.enabled = 1;
+         depth_stencil.depth.writemask = 1;
+         depth_stencil.depth.func = PIPE_FUNC_ALWAYS;
+      }
+
+      if (stencil) {
+         struct pipe_stencil_ref stencil_ref;
+         memset(&stencil_ref, 0, sizeof(stencil_ref));
+         depth_stencil.stencil[0].enabled = 1;
+         depth_stencil.stencil[0].func = PIPE_FUNC_ALWAYS;
+         depth_stencil.stencil[0].fail_op = PIPE_STENCIL_OP_REPLACE;
+         depth_stencil.stencil[0].zpass_op = PIPE_STENCIL_OP_REPLACE;
+         depth_stencil.stencil[0].zfail_op = PIPE_STENCIL_OP_REPLACE;
+         depth_stencil.stencil[0].valuemask = 0xff;
+         depth_stencil.stencil[0].writemask = ctx->Stencil.WriteMask[0] & 0xff;
+         stencil_ref.ref_value[0] = ctx->Stencil.Clear;
+         cso_set_stencil_ref(st->cso_context, &stencil_ref);
+      }
+
+      cso_set_depth_stencil_alpha(st->cso_context, &depth_stencil);
+   }
+
+   cso_set_vertex_elements(st->cso_context, 2, st->velems_util_draw);
+
+   cso_set_rasterizer(st->cso_context, &st->clear.raster);
+
+   /* viewport state: viewport matching window dims */
+   {
+      const GLboolean invert = (st_fb_orientation(fb) == Y_0_TOP);
+      struct pipe_viewport_state vp;
+      vp.scale[0] = 0.5f * fb_width;
+      vp.scale[1] = fb_height * (invert ? -0.5f : 0.5f);
+      vp.scale[2] = 1.0f;
+      vp.scale[3] = 1.0f;
+      vp.translate[0] = 0.5f * fb_width;
+      vp.translate[1] = 0.5f * fb_height;
+      vp.translate[2] = 0.0f;
+      vp.translate[3] = 0.0f;
+      cso_set_viewport(st->cso_context, &vp);
+   }
+
+   cso_set_clip(st->cso_context, &st->clear.clip);
+   cso_set_fragment_shader_handle(st->cso_context, st->clear.fs);
+   cso_set_vertex_shader_handle(st->cso_context, st->clear.vs);
+
+   /* draw quad matching scissor rect (XXX verify coord round-off) */
+   draw_quad(st, x0, y0, x1, y1,
+             (GLfloat) ctx->Depth.Clear, ctx->Color.ClearColor);
+
+   /* Restore pipe state */
+   cso_restore_blend(st->cso_context);
+   cso_restore_stencil_ref(st->cso_context);
+   cso_restore_depth_stencil_alpha(st->cso_context);
+   cso_restore_rasterizer(st->cso_context);
+   cso_restore_viewport(st->cso_context);
+   cso_restore_clip(st->cso_context);
+   cso_restore_fragment_shader(st->cso_context);
+   cso_restore_vertex_shader(st->cso_context);
+   cso_restore_vertex_elements(st->cso_context);
+   cso_restore_vertex_buffers(st->cso_context);
+}
+
+
+/**
+ * Determine if we need to clear the depth buffer by drawing a quad.
+ */
+static INLINE GLboolean
+check_clear_color_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb)
+{
+   if (ctx->Scissor.Enabled &&
+       (ctx->Scissor.X != 0 ||
+        ctx->Scissor.Y != 0 ||
+        ctx->Scissor.Width < rb->Width ||
+        ctx->Scissor.Height < rb->Height))
+      return GL_TRUE;
+
+   if (!ctx->Color.ColorMask[0][0] ||
+       !ctx->Color.ColorMask[0][1] ||
+       !ctx->Color.ColorMask[0][2] ||
+       !ctx->Color.ColorMask[0][3])
+      return GL_TRUE;
+
+   return GL_FALSE;
+}
+
+
+/**
+ * Determine if we need to clear the combiend depth/stencil buffer by
+ * drawing a quad.
+ */
+static INLINE GLboolean
+check_clear_depth_stencil_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb)
+{
+   const GLuint stencilMax = 0xff;
+   GLboolean maskStencil
+      = (ctx->Stencil.WriteMask[0] & stencilMax) != stencilMax;
+
+   assert(rb->Format == MESA_FORMAT_S8 ||
+          rb->Format == MESA_FORMAT_Z24_S8 ||
+          rb->Format == MESA_FORMAT_S8_Z24);
+
+   if (ctx->Scissor.Enabled &&
+       (ctx->Scissor.X != 0 ||
+        ctx->Scissor.Y != 0 ||
+        ctx->Scissor.Width < rb->Width ||
+        ctx->Scissor.Height < rb->Height))
+      return GL_TRUE;
+
+   if (maskStencil)
+      return GL_TRUE;
+
+   return GL_FALSE;
+}
+
+
+/**
+ * Determine if we need to clear the depth buffer by drawing a quad.
+ */
+static INLINE GLboolean
+check_clear_depth_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb,
+                            boolean ds_separate)
+{
+   const struct st_renderbuffer *strb = st_renderbuffer(rb);
+   const GLboolean isDS = util_format_is_depth_and_stencil(strb->surface->format);
+
+   if (ctx->Scissor.Enabled &&
+       (ctx->Scissor.X != 0 ||
+        ctx->Scissor.Y != 0 ||
+        ctx->Scissor.Width < rb->Width ||
+        ctx->Scissor.Height < rb->Height))
+      return GL_TRUE;
+
+   if (!ds_separate && isDS && ctx->DrawBuffer->Visual.stencilBits > 0)
+      return GL_TRUE;
+
+   return GL_FALSE;
+}
+
+
+/**
+ * Determine if we need to clear the stencil buffer by drawing a quad.
+ */
+static INLINE GLboolean
+check_clear_stencil_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb,
+                              boolean ds_separate)
+{
+   const struct st_renderbuffer *strb = st_renderbuffer(rb);
+   const GLboolean isDS = util_format_is_depth_and_stencil(strb->surface->format);
+   const GLuint stencilMax = 0xff;
+   const GLboolean maskStencil
+      = (ctx->Stencil.WriteMask[0] & stencilMax) != stencilMax;
+
+   assert(rb->Format == MESA_FORMAT_S8 ||
+          rb->Format == MESA_FORMAT_Z24_S8 ||
+          rb->Format == MESA_FORMAT_S8_Z24);
+
+   if (maskStencil) 
+      return GL_TRUE;
+
+   if (ctx->Scissor.Enabled &&
+       (ctx->Scissor.X != 0 ||
+        ctx->Scissor.Y != 0 ||
+        ctx->Scissor.Width < rb->Width ||
+        ctx->Scissor.Height < rb->Height))
+      return GL_TRUE;
+
+   /* This is correct, but it is necessary to look at the depth clear
+    * value held in the surface when it comes time to issue the clear,
+    * rather than taking depth and stencil clear values from the
+    * current state.
+    */
+   if (!ds_separate && isDS && ctx->DrawBuffer->Visual.depthBits > 0)
+      return GL_TRUE;
+
+   return GL_FALSE;
+}
+
+
+
+/**
+ * Called when we need to flush.
+ */
+void
+st_flush_clear(struct st_context *st)
+{
+   /* Release vertex buffer to avoid synchronous rendering if we were
+    * to map it in the next frame.
+    */
+   pipe_resource_reference(&st->clear.vbuf, NULL);
+   st->clear.vbuf_slot = 0;
+}
+ 
+
+
+/**
+ * Called via ctx->Driver.Clear()
+ */
+static void
+st_Clear(struct gl_context *ctx, GLbitfield mask)
+{
+   static const GLbitfield BUFFER_BITS_DS
+      = (BUFFER_BIT_DEPTH | BUFFER_BIT_STENCIL);
+   struct st_context *st = st_context(ctx);
+   struct gl_renderbuffer *depthRb
+      = ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
+   struct gl_renderbuffer *stencilRb
+      = ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;
+   GLbitfield quad_buffers = 0x0;
+   GLbitfield clear_buffers = 0x0;
+   GLuint i;
+
+   /* This makes sure the pipe has the latest scissor, etc values */
+   st_validate_state( st );
+
+   if (mask & BUFFER_BITS_COLOR) {
+      for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) {
+         GLuint b = ctx->DrawBuffer->_ColorDrawBufferIndexes[i];
+
+         if (mask & (1 << b)) {
+            struct gl_renderbuffer *rb
+               = ctx->DrawBuffer->Attachment[b].Renderbuffer;
+            struct st_renderbuffer *strb = st_renderbuffer(rb);
+
+            if (!strb || !strb->surface)
+               continue;
+
+            if (check_clear_color_with_quad( ctx, rb ))
+               quad_buffers |= PIPE_CLEAR_COLOR;
+            else
+               clear_buffers |= PIPE_CLEAR_COLOR;
+         }
+      }
+   }
+
+   if ((mask & BUFFER_BITS_DS) == BUFFER_BITS_DS && depthRb == stencilRb) {
+      /* clearing combined depth + stencil */
+      struct st_renderbuffer *strb = st_renderbuffer(depthRb);
+
+      if (strb->surface) {
+         if (check_clear_depth_stencil_with_quad(ctx, depthRb))
+            quad_buffers |= PIPE_CLEAR_DEPTHSTENCIL;
+         else
+            clear_buffers |= PIPE_CLEAR_DEPTHSTENCIL;
+      }
+   }
+   else {
+      /* separate depth/stencil clears */
+      /* I don't think truly separate buffers are actually possible in gallium or hw? */
+      if (mask & BUFFER_BIT_DEPTH) {
+         struct st_renderbuffer *strb = st_renderbuffer(depthRb);
+
+         if (strb->surface) {
+            if (check_clear_depth_with_quad(ctx, depthRb,
+                                            st->clear.enable_ds_separate))
+               quad_buffers |= PIPE_CLEAR_DEPTH;
+            else
+               clear_buffers |= PIPE_CLEAR_DEPTH;
+         }
+      }
+      if (mask & BUFFER_BIT_STENCIL) {
+         struct st_renderbuffer *strb = st_renderbuffer(stencilRb);
+
+         if (strb->surface) {
+            if (check_clear_stencil_with_quad(ctx, stencilRb,
+                                              st->clear.enable_ds_separate))
+               quad_buffers |= PIPE_CLEAR_STENCIL;
+            else
+               clear_buffers |= PIPE_CLEAR_STENCIL;
+         }
+      }
+   }
+
+   /*
+    * If we're going to use clear_with_quad() for any reason, use it for
+    * everything possible.
+    */
+   if (quad_buffers) {
+      quad_buffers |= clear_buffers;
+      clear_with_quad(ctx,
+                      quad_buffers & PIPE_CLEAR_COLOR,
+                      quad_buffers & PIPE_CLEAR_DEPTH,
+                      quad_buffers & PIPE_CLEAR_STENCIL);
+   } else if (clear_buffers) {
+      /* driver cannot know it can clear everything if the buffer
+       * is a combined depth/stencil buffer but this wasn't actually
+       * required from the visual. Hence fix this up to avoid potential
+       * read-modify-write in the driver.
+       */
+      if ((clear_buffers & PIPE_CLEAR_DEPTHSTENCIL) &&
+          ((clear_buffers & PIPE_CLEAR_DEPTHSTENCIL) != PIPE_CLEAR_DEPTHSTENCIL) &&
+          (depthRb == stencilRb) &&
+          (ctx->DrawBuffer->Visual.depthBits == 0 ||
+           ctx->DrawBuffer->Visual.stencilBits == 0))
+         clear_buffers |= PIPE_CLEAR_DEPTHSTENCIL;
+      st->pipe->clear(st->pipe, clear_buffers, ctx->Color.ClearColor,
+                      ctx->Depth.Clear, ctx->Stencil.Clear);
+   }
+   if (mask & BUFFER_BIT_ACCUM)
+      st_clear_accum_buffer(ctx,
+                            ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer);
+}
+
+
+void
+st_init_clear_functions(struct dd_function_table *functions)
+{
+   functions->Clear = st_Clear;
+}