gallium: new util_draw_texquad() function.

1 files changed, 112 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_draw_quad.c b/src/gallium/auxiliary/util/u_draw_quad.c
new file mode 100644
index 0000000000..79a69de633
--- /dev/null
+++ b/src/gallium/auxiliary/util/u_draw_quad.c
@@ -0,0 +1,112 @@
+/**************************************************************************
+ *
+ * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * 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.
+ *
+ **************************************************************************/
+
+
+#include "pipe/p_context.h"
+#include "pipe/p_defines.h"
+#include "pipe/p_inlines.h"
+#include "pipe/p_winsys.h"
+#include "util/u_draw_quad.h"
+
+
+/**
+ * Draw screen-aligned textured quad.
+ */
+void 
+util_draw_texquad(struct pipe_context *pipe,
+                  float x0, float y0, float x1, float y1, float z)
+{
+   struct pipe_buffer *vbuf;
+   struct pipe_vertex_buffer vbuffer;
+   struct pipe_vertex_element velement;
+   uint numAttribs = 2, vertexBytes, i, j;
+   float *v;
+
+   vertexBytes = 4 * (4 * numAttribs * sizeof(float));
+
+   /* XXX create one-time */
+   vbuf = pipe->winsys->buffer_create(pipe->winsys, 32,
+                                      PIPE_BUFFER_USAGE_VERTEX, vertexBytes);
+   assert(vbuf);
+
+   v = (float *) pipe->winsys->buffer_map(pipe->winsys, vbuf,
+                                          PIPE_BUFFER_USAGE_CPU_WRITE);
+
+   /*
+    * Load vertex buffer
+    */
+   for (i = j = 0; i < 4; i++) {
+      v[j + 2] = z;   /* z */
+      v[j + 3] = 1.0; /* w */
+      v[j + 6] = 0.0; /* r */
+      v[j + 7] = 1.0; /* q */
+      j += 8;
+   }
+
+   v[0] = x0;
+   v[1] = y0;
+   v[4] = 0.0; /*s*/
+   v[5] = 0.0; /*t*/
+
+   v[8] = x1;
+   v[9] = y0;
+   v[12] = 1.0;
+   v[13] = 0.0;
+
+   v[16] = x1;
+   v[17] = y1;
+   v[20] = 1.0;
+   v[21] = 1.0;
+
+   v[24] = x0;
+   v[25] = y1;
+   v[28] = 0.0;
+   v[29] = 1.0;
+
+   pipe->winsys->buffer_unmap(pipe->winsys, vbuf);
+
+   /* tell pipe about the vertex buffer */
+   vbuffer.buffer = vbuf;
+   vbuffer.pitch = numAttribs * 4 * sizeof(float);  /* vertex size */
+   vbuffer.buffer_offset = 0;
+   pipe->set_vertex_buffer(pipe, 0, &vbuffer);
+
+   /* tell pipe about the vertex attributes */
+   for (i = 0; i < numAttribs; i++) {
+      velement.src_offset = i * 4 * sizeof(float);
+      velement.vertex_buffer_index = 0;
+      velement.src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
+      velement.nr_components = 4;
+      pipe->set_vertex_element(pipe, i, &velement);
+   }
+
+   /* draw */
+   pipe->draw_arrays(pipe, PIPE_PRIM_TRIANGLE_FAN, 0, 4);
+
+   /* XXX: do one-time */
+   pipe_buffer_reference(pipe->winsys, &vbuf, NULL);
+}