Add a test case for cogl_buffer_map_range

This adds a small test case which maps a sub region of a small
attribute buffer and replaces the texture coordinates of one of the
vertices. The vertices are then drawn and the correct colours are
checked.

There is now a new test requirement for the
COGL_FEATURE_ID_MAP_BUFFER_FOR_WRITE feature which this test requires.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

(cherry picked from commit 22183265b021dd038338b4398056c0a1eae77edb)

tests/conform/Makefile.am

@@ -58,6 +58,7 @@ test_sources = \
 	test-euler-quaternion.c \
 	test-layer-remove.c \
 	test-alpha-test.c \
+	test-map-buffer-range.c \
 	$(NULL)
 
 test_conformance_SOURCES = $(common_sources) $(test_sources)

tests/conform/test-conform-main.c

@@ -102,6 +102,8 @@ main (int argc, char **argv)
 
   ADD_TEST (test_alpha_test, 0);
 
+  ADD_TEST (test_map_buffer_range, TEST_REQUIREMENT_MAP_WRITE);
+
   UNPORTED_TEST (test_viewport);
 
   ADD_TEST (test_gles2_context, TEST_REQUIREMENT_GLES2_CONTEXT);

tests/conform/test-map-buffer-range.c

@@ -0,0 +1,122 @@
+#include <cogl/cogl.h>
+
+#include <string.h>
+
+#include "test-utils.h"
+
+static uint8_t
+tex_data[2 * 2 * 4] =
+  {
+    0xff, 0x00, 0x00, 0xff, 0x00, 0xff, 0x00, 0xff,
+    0x00, 0x00, 0xff, 0xff, 0xff, 0x00, 0xff, 0xff
+  };
+
+/* Vertex data for a quad with all of the texture coordinates set to
+ * the top left (red) pixel */
+static CoglVertexP2T2
+vertex_data[4] =
+  {
+    { -1, -1, 0, 0 },
+    { 1, -1, 0, 0 },
+    { -1, 1, 0, 0 },
+    { 1, 1, 0, 0 }
+  };
+
+void
+test_map_buffer_range (void)
+{
+  CoglTexture2D *tex;
+  CoglPipeline *pipeline;
+  int fb_width, fb_height;
+  CoglAttributeBuffer *buffer;
+  CoglVertexP2T2 *data;
+  CoglAttribute *pos_attribute;
+  CoglAttribute *tex_coord_attribute;
+
+  tex = cogl_texture_2d_new_from_data (ctx,
+                                       2, 2, /* width/height */
+                                       COGL_PIXEL_FORMAT_RGBA_8888_PRE,
+                                       COGL_PIXEL_FORMAT_ANY,
+                                       2 * 4, /* rowstride */
+                                       tex_data,
+                                       NULL /* error */);
+
+  pipeline = cogl_pipeline_new (ctx);
+
+  cogl_pipeline_set_layer_texture (pipeline, 0, COGL_TEXTURE (tex));
+  cogl_pipeline_set_layer_filters (pipeline,
+                                   0, /* layer */
+                                   COGL_PIPELINE_FILTER_NEAREST,
+                                   COGL_PIPELINE_FILTER_NEAREST);
+  cogl_pipeline_set_layer_wrap_mode (pipeline,
+                                     0, /* layer */
+                                     COGL_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE);
+
+  fb_width = cogl_framebuffer_get_width (fb);
+  fb_height = cogl_framebuffer_get_height (fb);
+
+  buffer = cogl_attribute_buffer_new (ctx,
+                                      sizeof (vertex_data),
+                                      vertex_data);
+
+  /* Replace the texture coordinates of the third vertex with the
+   * coordinates for a green texel */
+  data = cogl_buffer_map_range (COGL_BUFFER (buffer),
+                                sizeof (vertex_data[0]) * 2,
+                                sizeof (vertex_data[0]),
+                                COGL_BUFFER_ACCESS_WRITE,
+                                COGL_BUFFER_MAP_HINT_DISCARD_RANGE);
+  g_assert (data != NULL);
+
+  data->x = vertex_data[2].x;
+  data->y = vertex_data[2].y;
+  data->s = 1.0f;
+  data->t = 0.0f;
+
+  cogl_buffer_unmap (COGL_BUFFER (buffer));
+
+  pos_attribute =
+    cogl_attribute_new (buffer,
+                        "cogl_position_in",
+                        sizeof (vertex_data[0]),
+                        offsetof (CoglVertexP2T2, x),
+                        2, /* n_components */
+                        COGL_ATTRIBUTE_TYPE_FLOAT);
+  tex_coord_attribute =
+    cogl_attribute_new (buffer,
+                        "cogl_tex_coord_in",
+                        sizeof (vertex_data[0]),
+                        offsetof (CoglVertexP2T2, s),
+                        2, /* n_components */
+                        COGL_ATTRIBUTE_TYPE_FLOAT);
+
+  cogl_framebuffer_clear4f (fb,
+                            COGL_BUFFER_BIT_COLOR,
+                            0, 0, 0, 1);
+
+  cogl_framebuffer_vdraw_attributes (fb,
+                                     pipeline,
+                                     COGL_VERTICES_MODE_TRIANGLE_STRIP,
+                                     0, /* first_vertex */
+                                     4, /* n_vertices */
+                                     pos_attribute,
+                                     tex_coord_attribute,
+                                     NULL);
+
+  /* Top left pixel should be the one that is replaced to be green */
+  test_utils_check_pixel (fb, 1, 1, 0x00ff00ff);
+  /* The other three corners should be left as red */
+  test_utils_check_pixel (fb, fb_width - 2, 1, 0xff0000ff);
+  test_utils_check_pixel (fb, 1, fb_height - 2, 0xff0000ff);
+  test_utils_check_pixel (fb, fb_width - 2, fb_height - 2, 0xff0000ff);
+
+  cogl_object_unref (buffer);
+  cogl_object_unref (pos_attribute);
+  cogl_object_unref (tex_coord_attribute);
+
+  cogl_object_unref (pipeline);
+  cogl_object_unref (tex);
+
+  if (cogl_test_verbose ())
+    g_print ("OK\n");
+}

tests/conform/test-utils.c

@@ -83,6 +83,12 @@ test_utils_init (TestFlags flags)
       missing_requirement = TRUE;
     }
 
+  if (flags & TEST_REQUIREMENT_MAP_WRITE &&
+      !cogl_has_feature (ctx, COGL_FEATURE_ID_MAP_BUFFER_FOR_WRITE))
+    {
+      missing_requirement = TRUE;
+    }
+
   if (flags & TEST_KNOWN_FAILURE)
     {
       missing_requirement = TRUE;

tests/conform/test-utils.h

@@ -14,7 +14,8 @@ typedef enum _TestFlags
   TEST_REQUIREMENT_NPOT          = 1<<2,
   TEST_REQUIREMENT_TEXTURE_3D    = 1<<3,
   TEST_REQUIREMENT_POINT_SPRITE  = 1<<4,
-  TEST_REQUIREMENT_GLES2_CONTEXT = 1<<5
+  TEST_REQUIREMENT_GLES2_CONTEXT = 1<<5,
+  TEST_REQUIREMENT_MAP_WRITE     = 1<<6
 } TestFlags;
 
 extern CoglContext *ctx;