[Mesa-dev] [PATCH] mesa: refactor meta GetTexImage code

Brian Paul brianp at vmware.com
Wed Aug 17 16:06:18 PDT 2011


We shouldn't directly call meta functions from core Mesa because that
creates a dependency on swrast.

The new _mesa_meta_GetTexImage() function trivially calls the meta
decompression routine for compressed textures vs. the core
_mesa_get_teximage() fallback function for uncompressed textures.

In the state tracker, use the existing code for glGetTexImage() that
handles decompression via quad rendering already.
---
 src/mesa/drivers/common/driverfuncs.c |    2 +-
 src/mesa/drivers/common/meta.c        |   39 +++++++++--
 src/mesa/drivers/common/meta.h        |   12 ++--
 src/mesa/main/texgetimage.c           |  125 ++++++++++++++++-----------------
 src/mesa/state_tracker/st_context.c   |    4 -
 5 files changed, 102 insertions(+), 80 deletions(-)

diff --git a/src/mesa/drivers/common/driverfuncs.c b/src/mesa/drivers/common/driverfuncs.c
index 78caa05..bf4f5e4 100644
--- a/src/mesa/drivers/common/driverfuncs.c
+++ b/src/mesa/drivers/common/driverfuncs.c
@@ -94,7 +94,7 @@ _mesa_init_driver_functions(struct dd_function_table *driver)
    driver->TexSubImage1D = _mesa_store_texsubimage1d;
    driver->TexSubImage2D = _mesa_store_texsubimage2d;
    driver->TexSubImage3D = _mesa_store_texsubimage3d;
-   driver->GetTexImage = _mesa_get_teximage;
+   driver->GetTexImage = _mesa_meta_GetTexImage;
    driver->CopyTexSubImage1D = _mesa_meta_CopyTexSubImage1D;
    driver->CopyTexSubImage2D = _mesa_meta_CopyTexSubImage2D;
    driver->CopyTexSubImage3D = _mesa_meta_CopyTexSubImage3D;
diff --git a/src/mesa/drivers/common/meta.c b/src/mesa/drivers/common/meta.c
index 751f3b6..537e894 100644
--- a/src/mesa/drivers/common/meta.c
+++ b/src/mesa/drivers/common/meta.c
@@ -59,6 +59,7 @@
 #include "main/stencil.h"
 #include "main/texobj.h"
 #include "main/texenv.h"
+#include "main/texgetimage.h"
 #include "main/teximage.h"
 #include "main/texparam.h"
 #include "main/texstate.h"
@@ -3119,12 +3120,12 @@ _mesa_meta_CopyColorSubTable(struct gl_context *ctx,GLenum target, GLsizei start
  * \param dest  destination buffer
  * \param destRowLength  dest image rowLength (ala GL_PACK_ROW_LENGTH)
  */
-void
-_mesa_meta_decompress_texture_image(struct gl_context *ctx,
-                                    struct gl_texture_image *texImage,
-                                    GLuint slice,
-                                    GLenum destFormat, GLenum destType,
-                                    GLvoid *dest, GLint destRowLength)
+static void
+decompress_texture_image(struct gl_context *ctx,
+                         struct gl_texture_image *texImage,
+                         GLuint slice,
+                         GLenum destFormat, GLenum destType,
+                         GLvoid *dest, GLint destRowLength)
 {
    struct decompress_state *decompress = &ctx->Meta->Decompress;
    struct gl_texture_object *texObj = texImage->TexObject;
@@ -3294,3 +3295,29 @@ _mesa_meta_decompress_texture_image(struct gl_context *ctx,
    }
 }
 
+
+/**
+ * This is just a wrapper around _mesa_get_tex_image() and
+ * decompress_texture_image().  Meta functions should not be directly called
+ * from core Mesa.
+ */
+void
+_mesa_meta_GetTexImage(struct gl_context *ctx, GLenum target, GLint level,
+                       GLenum format, GLenum type, GLvoid *pixels,
+                       struct gl_texture_object *texObj,
+                       struct gl_texture_image *texImage)
+{
+   if (_mesa_is_format_compressed(texImage->TexFormat)) {
+      const GLuint slice = 0; /* only 2D compressed textures for now */
+      /* Need to unlock the texture here to prevent deadlock... */
+      _mesa_unlock_texture(ctx, texObj);
+      decompress_texture_image(ctx, texImage, slice, format, type, pixels,
+                               ctx->Pack.RowLength);
+      /* ... and relock it */
+      _mesa_lock_texture(ctx, texObj);
+   }
+   else {
+      _mesa_get_teximage(ctx, target, level, format, type, pixels,
+                          texObj, texImage);
+   }
+}
diff --git a/src/mesa/drivers/common/meta.h b/src/mesa/drivers/common/meta.h
index 50389c9..b4cfe3e 100644
--- a/src/mesa/drivers/common/meta.h
+++ b/src/mesa/drivers/common/meta.h
@@ -107,11 +107,11 @@ _mesa_meta_CopyConvolutionFilter2D(struct gl_context *ctx, GLenum target,
                                    GLenum internalFormat, GLint x, GLint y,
                                    GLsizei width, GLsizei height);
 
-void
-_mesa_meta_decompress_texture_image(struct gl_context *ctx,
-                                    struct gl_texture_image *texImage,
-                                    GLuint slice,
-                                    GLenum destFormat, GLenum destType,
-                                    GLvoid *dest, GLint destRowLength);
+extern void
+_mesa_meta_GetTexImage(struct gl_context *ctx, GLenum target, GLint level,
+                       GLenum format, GLenum type, GLvoid *pixels,
+                       struct gl_texture_object *texObj,
+                       struct gl_texture_image *texImage);
+
 
 #endif /* META_H */
diff --git a/src/mesa/main/texgetimage.c b/src/mesa/main/texgetimage.c
index 4d97c88..723f4b5 100644
--- a/src/mesa/main/texgetimage.c
+++ b/src/mesa/main/texgetimage.c
@@ -42,7 +42,6 @@
 #include "pbo.h"
 #include "texgetimage.h"
 #include "teximage.h"
-#include "drivers/common/meta.h"
 
 
 /**
@@ -257,6 +256,7 @@ get_tex_ycbcr(struct gl_context *ctx, GLuint dimensions,
 /**
  * glGetTexImage for (s)RGBA, Luminance, etc. pixels.
  * This is the slow way since we use texture sampling.
+ * NOTE: the texture cannot be compressed.
  */
 static void
 get_tex_rgba(struct gl_context *ctx, GLuint dimensions,
@@ -293,77 +293,68 @@ get_tex_rgba(struct gl_context *ctx, GLuint dimensions,
    texFormat = _mesa_get_srgb_format_linear(texImage->TexFormat);
 
    for (img = 0; img < depth; img++) {
-      if (_mesa_is_format_compressed(texImage->TexFormat)) {
-         _mesa_unlock_texture(ctx, texImage->TexObject);
-         _mesa_meta_decompress_texture_image(ctx, texImage, img,
-                                             format, type, pixels,
-                                             ctx->Pack.RowLength);
-         _mesa_lock_texture(ctx, texImage->TexObject);
+      GLfloat (*rgba)[4];
+      GLubyte *srcMap;
+      GLint srcRowStride;
+      GLint row;
+
+      rgba = (GLfloat (*)[4]) malloc(4 * width * sizeof(GLfloat));
+      if (!rgba) {
+         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glGetTexImage");
+         return;
       }
-      else {
-         GLfloat (*rgba)[4];
-         GLubyte *srcMap;
-         GLint srcRowStride;
-         GLint row;
-
-         rgba = (GLfloat (*)[4]) malloc(4 * width * sizeof(GLfloat));
-         if (!rgba) {
-            _mesa_error(ctx, GL_OUT_OF_MEMORY, "glGetTexImage");
-            return;
-         }
 
-         /* map src texture buffer */
-         ctx->Driver.MapTextureImage(ctx, texImage, img,
-                                     0, 0, width, height, GL_MAP_READ_BIT,
-                                     &srcMap, &srcRowStride);
-
-         for (row = 0; row < height; row++) {
-            void *dest = _mesa_image_address(dimensions, &ctx->Pack, pixels,
-                                             width, height, format, type,
-                                             img, row, 0);
-            GLint i;
-
-            _mesa_unpack_rgba_row(texFormat, width, srcMap, rgba);
-            srcMap += srcRowStride;
-
-            if (texImage->_BaseFormat == GL_ALPHA) {
-               for (i = 0; i < width; i++) {
-                  rgba[i][RCOMP] = 0.0F;
-                  rgba[i][GCOMP] = 0.0F;
-                  rgba[i][BCOMP] = 0.0F;
-               }
+      /* map src texture buffer */
+      ctx->Driver.MapTextureImage(ctx, texImage, img,
+                                  0, 0, width, height, GL_MAP_READ_BIT,
+                                  &srcMap, &srcRowStride);
+
+      for (row = 0; row < height; row++) {
+         void *dest = _mesa_image_address(dimensions, &ctx->Pack, pixels,
+                                          width, height, format, type,
+                                          img, row, 0);
+         GLint i;
+
+         _mesa_unpack_rgba_row(texFormat, width, srcMap, rgba);
+         srcMap += srcRowStride;
+
+         if (texImage->_BaseFormat == GL_ALPHA) {
+            for (i = 0; i < width; i++) {
+               rgba[i][RCOMP] = 0.0F;
+               rgba[i][GCOMP] = 0.0F;
+               rgba[i][BCOMP] = 0.0F;
             }
-            else if (texImage->_BaseFormat == GL_LUMINANCE) {
-               for (i = 0; i < width; i++) {
-                  rgba[i][GCOMP] = 0.0F;
-                  rgba[i][BCOMP] = 0.0F;
-                  rgba[i][ACOMP] = 1.0F;
-               }
+         }
+         else if (texImage->_BaseFormat == GL_LUMINANCE) {
+            for (i = 0; i < width; i++) {
+               rgba[i][GCOMP] = 0.0F;
+               rgba[i][BCOMP] = 0.0F;
+               rgba[i][ACOMP] = 1.0F;
             }
-            else if (texImage->_BaseFormat == GL_LUMINANCE_ALPHA) {
-               for (i = 0; i < width; i++) {
-                  rgba[i][GCOMP] = 0.0F;
-                  rgba[i][BCOMP] = 0.0F;
-               }
+         }
+         else if (texImage->_BaseFormat == GL_LUMINANCE_ALPHA) {
+            for (i = 0; i < width; i++) {
+               rgba[i][GCOMP] = 0.0F;
+               rgba[i][BCOMP] = 0.0F;
             }
-            else if (texImage->_BaseFormat == GL_INTENSITY) {
-               for (i = 0; i < width; i++) {
-                  rgba[i][GCOMP] = 0.0F;
-                  rgba[i][BCOMP] = 0.0F;
-                  rgba[i][ACOMP] = 1.0F;
-               }
+         }
+         else if (texImage->_BaseFormat == GL_INTENSITY) {
+            for (i = 0; i < width; i++) {
+               rgba[i][GCOMP] = 0.0F;
+               rgba[i][BCOMP] = 0.0F;
+               rgba[i][ACOMP] = 1.0F;
             }
-
-            _mesa_pack_rgba_span_float(ctx, width, (GLfloat (*)[4]) rgba,
-                                       format, type, dest,
-                                       &ctx->Pack, transferOps);
          }
 
-         /* Unmap the src texture buffer */
-         ctx->Driver.UnmapTextureImage(ctx, texImage, img);
-
-         free(rgba);
+         _mesa_pack_rgba_span_float(ctx, width, (GLfloat (*)[4]) rgba,
+                                    format, type, dest,
+                                    &ctx->Pack, transferOps);
       }
+
+      /* Unmap the src texture buffer */
+      ctx->Driver.UnmapTextureImage(ctx, texImage, img);
+
+      free(rgba);
    }
 }
 
@@ -471,6 +462,12 @@ get_tex_memcpy(struct gl_context *ctx, GLenum format, GLenum type,
  * All error checking will have been done before this routine is called.
  * We'll call ctx->Driver.MapTextureImage() to access the data, then
  * unmap with ctx->Driver.UnmapTextureImage().
+ *
+ * NOTE that compressed textures are not handled here.  Decompression can
+ * be done in two ways:
+ * 1. Use software to decompress the blocks.
+ * 2. Render a textured quad with the compressed texture.
+ * The former is undesirable.  The later can be done with a "meta" function.
  */
 void
 _mesa_get_teximage(struct gl_context *ctx, GLenum target, GLint level,
@@ -480,6 +477,8 @@ _mesa_get_teximage(struct gl_context *ctx, GLenum target, GLint level,
 {
    GLuint dimensions;
 
+   assert(!_mesa_is_format_compressed(texImage->TexFormat));
+
    switch (target) {
    case GL_TEXTURE_1D:
       dimensions = 1;
diff --git a/src/mesa/state_tracker/st_context.c b/src/mesa/state_tracker/st_context.c
index e994e2e..6d4bc54 100644
--- a/src/mesa/state_tracker/st_context.c
+++ b/src/mesa/state_tracker/st_context.c
@@ -29,7 +29,6 @@
 #include "main/context.h"
 #include "main/samplerobj.h"
 #include "main/shaderobj.h"
-#include "drivers/common/meta.h"
 #include "program/prog_cache.h"
 #include "vbo/vbo.h"
 #include "glapi/glapi.h"
@@ -184,8 +183,6 @@ struct st_context *st_create_context(gl_api api, struct pipe_context *pipe,
       return NULL;
    }
 
-   _mesa_meta_init(ctx);
-
    /* XXX: need a capability bit in gallium to query if the pipe
     * driver prefers DP4 or MUL/MAD for vertex transformation.
     */
@@ -258,7 +255,6 @@ void st_destroy_context( struct st_context *st )
 
    st_destroy_program_variants(st);
 
-   _mesa_meta_free(ctx);
    _mesa_free_context_data(ctx);
 
    st_destroy_context_priv(st);
-- 
1.7.3.4



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