st/mesa: add new st_copy_framebuffer_to_texture() function

This helper is used by the WGL state tracker to implement the
wglBindTexImageARB() function.

This is basically a new "meta" function.  However, we're not putting
it in the src/mesa/drivers/common/ directory because that code is not
linked with gallium-based drivers.

Reviewed-by: José Fonseca <[email protected]>
Reviewed-by: Charmaine Lee <[email protected]>

1 files changed, 140 insertions, 0 deletions

diff --git a/src/mesa/state_tracker/st_copytex.c b/src/mesa/state_tracker/st_copytex.c
new file mode 100644
index 00000000000..d246d8b6a71
--- /dev/null
+++ b/src/mesa/state_tracker/st_copytex.c
@@ -0,0 +1,140 @@
+/*
+ * Copyright 2015 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, sublicense,
+ * 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 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 NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS 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.
+ */
+
+#include "main/mtypes.h"
+#include "main/buffers.h"
+#include "main/errors.h"
+#include "main/fbobject.h"
+#include "main/get.h"
+#include "main/teximage.h"
+#include "main/texparam.h"
+#include "st_copytex.h"
+
+
+/**
+ * Copy a colorbuffer from the window system framebuffer (a window or
+ * pbuffer) to a texture.
+ * This is a helper used by the wglBindTexImageARB() function.
+ *
+ * \param srcBuffer  source buffer (GL_FRONT_LEFT, GL_BACK_LEFT, etc)
+ * \param fbWidth  width of the source framebuffer
+ * \param fbHeight  height of the source framebuffer
+ * \param texTarget  which texture target to copy to (GL_TEXTURE_1D/2D/CUBE_MAP)
+ * \param texLevel  which texture mipmap level to copy to
+ * \param cubeFace  which cube face to copy to (in [0,5])
+ * \param texFormat  what texture format to use, if texture doesn't exist
+ */
+void
+st_copy_framebuffer_to_texture(GLenum srcBuffer,
+                               GLint fbWidth, GLint fbHeight,
+                               GLenum texTarget, GLint texLevel,
+                               GLuint cubeFace, GLenum texFormat)
+{
+   GLint readFBOSave, readBufSave, width, height;
+
+   assert(cubeFace < 6);
+
+   /* Save current FBO / readbuffer */
+   _mesa_GetIntegerv(GL_READ_FRAMEBUFFER_BINDING, &readFBOSave);
+   _mesa_GetIntegerv(GL_READ_BUFFER, &readBufSave);
+
+   /* Read from the winsys buffer */
+   _mesa_BindFramebuffer(GL_READ_BUFFER, 0);
+   _mesa_ReadBuffer(srcBuffer);
+
+   /* copy image from pbuffer to texture */
+   switch (texTarget) {
+   case GL_TEXTURE_1D:
+      _mesa_GetTexLevelParameteriv(GL_TEXTURE_1D, texLevel,
+                                   GL_TEXTURE_WIDTH, &width);
+      if (width == fbWidth) {
+         /* replace existing texture */
+         _mesa_CopyTexSubImage1D(GL_TEXTURE_1D,
+                                 texLevel,
+                                 0,    /* xoffset */
+                                 0, 0, /* x, y */
+                                 fbWidth);
+      } else {
+         /* define initial texture */
+         _mesa_CopyTexImage1D(GL_TEXTURE_1D,
+                              texLevel,
+                              texFormat,
+                              0, 0, /* x, y */
+                              fbWidth, 0);
+      }
+      break;
+   case GL_TEXTURE_2D:
+      _mesa_GetTexLevelParameteriv(GL_TEXTURE_2D, texLevel,
+                                   GL_TEXTURE_WIDTH, &width);
+      _mesa_GetTexLevelParameteriv(GL_TEXTURE_2D, texLevel,
+                                   GL_TEXTURE_HEIGHT, &height);
+      if (width == fbWidth && height == fbHeight) {
+         /* replace existing texture */
+         _mesa_CopyTexSubImage2D(GL_TEXTURE_2D,
+                                 texLevel,
+                                 0, 0, /* xoffset, yoffset */
+                                 0, 0, /* x, y */
+                                 fbWidth, fbHeight);
+      } else {
+         /* define initial texture */
+         _mesa_CopyTexImage2D(GL_TEXTURE_2D,
+                              texLevel,
+                              texFormat,
+                              0, 0, /* x, y */
+                              fbWidth, fbHeight, 0);
+      }
+      break;
+   case GL_TEXTURE_CUBE_MAP:
+      {
+         const GLenum target =
+            GL_TEXTURE_CUBE_MAP_POSITIVE_X + cubeFace;
+         _mesa_GetTexLevelParameteriv(target, texLevel,
+                                      GL_TEXTURE_WIDTH, &width);
+         _mesa_GetTexLevelParameteriv(target, texLevel,
+                                      GL_TEXTURE_HEIGHT, &height);
+         if (width == fbWidth && height == fbHeight) {
+            /* replace existing texture */
+            _mesa_CopyTexSubImage2D(target,
+                                    texLevel,
+                                    0, 0, /* xoffset, yoffset */
+                                    0, 0, /* x, y */
+                                    fbWidth, fbHeight);
+         } else {
+            /* define new texture */
+            _mesa_CopyTexImage2D(target,
+                                 texLevel,
+                                 texFormat,
+                                 0, 0, /* x, y */
+                                 fbWidth, fbHeight, 0);
+         }
+      }
+      break;
+   default:
+      _mesa_problem(NULL,
+                    "unexpected target in st_copy_framebuffer_to_texture()\n");
+   }
+
+   /* restore readbuffer */
+   _mesa_ReadBuffer(readBufSave);
+   _mesa_BindFramebuffer(GL_READ_BUFFER, readFBOSave);
+}