mesa: move glViewport and glDepthRange functions into new viewport.c file

A bit of refactoring with an eye toward ES2 and GL 3.1

1 files changed, 176 insertions, 0 deletions

diff --git a/src/mesa/main/viewport.c b/src/mesa/main/viewport.c
new file mode 100644
index 00000000000..ead856d32c3
--- /dev/null
+++ b/src/mesa/main/viewport.c
@@ -0,0 +1,176 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  7.5
+ *
+ * Copyright (C) 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, 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
+ * BRIAN PAUL 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.
+ */
+
+
+/**
+ * \file viewport.c
+ * glViewport and glDepthRange functions.
+ */
+
+
+#include "context.h"
+#include "macros.h"
+#include "viewport.h"
+
+
+/**
+ * Set the viewport.
+ * \sa Called via glViewport() or display list execution.
+ *
+ * Flushes the vertices and calls _mesa_set_viewport() with the given
+ * parameters.
+ */
+void GLAPIENTRY
+_mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
+   _mesa_set_viewport(ctx, x, y, width, height);
+}
+
+
+/**
+ * Set new viewport parameters and update derived state (the _WindowMap
+ * matrix).  Usually called from _mesa_Viewport().
+ * 
+ * \param ctx GL context.
+ * \param x, y coordinates of the lower left corner of the viewport rectangle.
+ * \param width width of the viewport rectangle.
+ * \param height height of the viewport rectangle.
+ */
+void
+_mesa_set_viewport(GLcontext *ctx, GLint x, GLint y,
+                    GLsizei width, GLsizei height)
+{
+   if (MESA_VERBOSE & VERBOSE_API)
+      _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
+
+   if (width < 0 || height < 0) {
+      _mesa_error(ctx,  GL_INVALID_VALUE,
+                   "glViewport(%d, %d, %d, %d)", x, y, width, height);
+      return;
+   }
+
+   /* clamp width and height to the implementation dependent range */
+   width  = CLAMP(width,  1, (GLsizei) ctx->Const.MaxViewportWidth);
+   height = CLAMP(height, 1, (GLsizei) ctx->Const.MaxViewportHeight);
+
+   ctx->Viewport.X = x;
+   ctx->Viewport.Width = width;
+   ctx->Viewport.Y = y;
+   ctx->Viewport.Height = height;
+   ctx->NewState |= _NEW_VIEWPORT;
+
+#if 1
+   /* XXX remove this someday.  Currently the DRI drivers rely on
+    * the WindowMap matrix being up to date in the driver's Viewport
+    * and DepthRange functions.
+    */
+   _math_matrix_viewport(&ctx->Viewport._WindowMap,
+                         ctx->Viewport.X, ctx->Viewport.Y,
+                         ctx->Viewport.Width, ctx->Viewport.Height,
+                         ctx->Viewport.Near, ctx->Viewport.Far,
+                         ctx->DrawBuffer->_DepthMaxF);
+#endif
+
+   if (ctx->Driver.Viewport) {
+      /* Many drivers will use this call to check for window size changes
+       * and reallocate the z/stencil/accum/etc buffers if needed.
+       */
+      ctx->Driver.Viewport(ctx, x, y, width, height);
+   }
+}
+
+
+/**
+ * Called by glDepthRange
+ *
+ * \param nearval  specifies the Z buffer value which should correspond to
+ *                 the near clip plane
+ * \param farval  specifies the Z buffer value which should correspond to
+ *                the far clip plane
+ */
+void GLAPIENTRY
+_mesa_DepthRange(GLclampd nearval, GLclampd farval)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
+
+   if (MESA_VERBOSE&VERBOSE_API)
+      _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
+
+   ctx->Viewport.Near = (GLfloat) CLAMP(nearval, 0.0, 1.0);
+   ctx->Viewport.Far = (GLfloat) CLAMP(farval, 0.0, 1.0);
+   ctx->NewState |= _NEW_VIEWPORT;
+
+#if 1
+   /* XXX remove this someday.  Currently the DRI drivers rely on
+    * the WindowMap matrix being up to date in the driver's Viewport
+    * and DepthRange functions.
+    */
+   _math_matrix_viewport(&ctx->Viewport._WindowMap,
+                         ctx->Viewport.X, ctx->Viewport.Y,
+                         ctx->Viewport.Width, ctx->Viewport.Height,
+                         ctx->Viewport.Near, ctx->Viewport.Far,
+                         ctx->DrawBuffer->_DepthMaxF);
+#endif
+
+   if (ctx->Driver.DepthRange) {
+      ctx->Driver.DepthRange(ctx, nearval, farval);
+   }
+}
+
+
+
+/** 
+ * Initialize the context viewport attribute group.
+ * \param ctx  the GL context.
+ */
+void _mesa_init_viewport(GLcontext *ctx)
+{
+   GLfloat depthMax = 65535.0F; /* sorf of arbitrary */
+
+   /* Viewport group */
+   ctx->Viewport.X = 0;
+   ctx->Viewport.Y = 0;
+   ctx->Viewport.Width = 0;
+   ctx->Viewport.Height = 0;
+   ctx->Viewport.Near = 0.0;
+   ctx->Viewport.Far = 1.0;
+   _math_matrix_ctr(&ctx->Viewport._WindowMap);
+
+   _math_matrix_viewport(&ctx->Viewport._WindowMap, 0, 0, 0, 0,
+                         0.0F, 1.0F, depthMax);
+}
+
+
+/** 
+ * Free the context viewport attribute group data.
+ * \param ctx  the GL context.
+ */
+void _mesa_free_viewport_data(GLcontext *ctx)
+{
+   _math_matrix_dtr(&ctx->Viewport._WindowMap);
+}
+