Add a conformance test for point sizes

This tries rendering some points at various sizes and checks that they
are the expected size and make a rectangle shape. This is currently
failing when the GLSL vertend is used because it flushes the point
size in the wrong place.

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

tests/conform/Makefile.am

@@ -50,6 +50,7 @@ test_sources = \
 	test-sparse-pipeline.c \
 	test-read-texture-formats.c \
 	test-write-texture-formats.c \
+	test-point-size.c \
 	$(NULL)
 
 test_conformance_SOURCES = $(common_sources) $(test_sources)

tests/conform/test-conform-main.c

@@ -99,6 +99,8 @@ main (int argc, char **argv)
 
   ADD_TEST (test_cogl_offscreen, 0);
 
+  ADD_TEST (test_cogl_point_size, 0);
+
   UNPORTED_TEST (test_cogl_viewport);
 
   g_printerr ("Unknown test name \"%s\"\n", argv[1]);

tests/conform/test-point-size.c

@@ -0,0 +1,103 @@
+#include <cogl/cogl2-experimental.h>
+
+#include "test-utils.h"
+
+/* This test assumes the GL driver supports point sizes up to 16
+   pixels. Cogl should probably have some way of querying the size so
+   we start from that instead */
+#define MAX_POINT_SIZE 16
+/* The size of the area that we'll paint each point in */
+#define POINT_BOX_SIZE (MAX_POINT_SIZE * 2)
+
+static int
+calc_coord_offset (int pos, int pos_index, int point_size)
+{
+  switch (pos_index)
+    {
+    case 0: return pos - point_size / 2 - 2;
+    case 1: return pos - point_size / 2 + 2;
+    case 2: return pos + point_size / 2 - 2;
+    case 3: return pos + point_size / 2 + 2;
+    }
+
+  g_assert_not_reached ();
+}
+
+static void
+verify_point_size (CoglFramebuffer *fb,
+                   int x_pos,
+                   int y_pos,
+                   int point_size)
+{
+  int y, x;
+
+  for (y = 0; y < 4; y++)
+    for (x = 0; x < 4; x++)
+      {
+        gboolean in_point = x >= 1 && x <= 2 && y >= 1 && y <= 2;
+        guint32 expected_pixel = in_point ? 0x00ff00ff : 0xff0000ff;
+
+        test_utils_check_pixel (calc_coord_offset (x_pos, x, point_size),
+                                calc_coord_offset (y_pos, y, point_size),
+                                expected_pixel);
+      }
+}
+
+void
+test_cogl_point_size (TestUtilsGTestFixture *fixture,
+                      void *data)
+{
+  TestUtilsSharedState *shared_state = data;
+  CoglContext *ctx = shared_state->ctx;
+  int fb_width = cogl_framebuffer_get_width (shared_state->fb);
+  int fb_height = cogl_framebuffer_get_height (shared_state->fb);
+  int point_size;
+  int x_pos;
+
+  cogl_framebuffer_orthographic (shared_state->fb,
+                                 0, 0, /* x_1, y_1 */
+                                 fb_width, /* x_2 */
+                                 fb_height /* y_2 */,
+                                 -1, 100 /* near/far */);
+
+  cogl_framebuffer_clear4f (shared_state->fb,
+                            COGL_BUFFER_BIT_COLOR,
+                            1.0f, 0.0f, 0.0f, 1.0f);
+
+  /* Try a rendering a single point with a few different point
+     sizes */
+  for (x_pos = 0, point_size = MAX_POINT_SIZE;
+       point_size >= 4;
+       x_pos += POINT_BOX_SIZE, point_size /= 2)
+    {
+      CoglPipeline *pipeline = cogl_pipeline_new (ctx);
+      CoglVertexP2 point = { x_pos + POINT_BOX_SIZE / 2,
+                             POINT_BOX_SIZE / 2 };
+      CoglPrimitive *prim =
+        cogl_primitive_new_p2 (ctx,
+                               COGL_VERTICES_MODE_POINTS,
+                               1, /* n_vertices */
+                               &point);
+
+      cogl_pipeline_set_point_size (pipeline, point_size);
+      cogl_pipeline_set_color4ub (pipeline, 0, 255, 0, 255);
+      cogl_framebuffer_draw_primitive (shared_state->fb,
+                                       pipeline,
+                                       prim);
+
+      cogl_object_unref (prim);
+      cogl_object_unref (pipeline);
+    }
+
+  /* Verify all of the points where drawn at the right size */
+  for (x_pos = 0, point_size = MAX_POINT_SIZE;
+       point_size >= 4;
+       x_pos += POINT_BOX_SIZE, point_size /= 2)
+    verify_point_size (shared_state->fb,
+                       x_pos + POINT_BOX_SIZE / 2,
+                       POINT_BOX_SIZE / 2,
+                       point_size);
+
+  if (cogl_test_verbose ())
+    g_print ("OK\n");
+}