tests/cogl: Migrate primitive and journal test

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2555>

src/tests/cogl/conform/meson.build

@@ -32,6 +32,7 @@ cogl_tests = [
   [ 'test-alpha-textures', [] ],
   [ 'test-texture-get-set-data', [] ],
   [ 'test-framebuffer-get-bits', [] ],
+  [ 'test-primitive-and-journal', [] ],
 ]
 
 cogl_test_conformance_includes = [

src/tests/cogl/conform/test-primitive-and-journal.c

@@ -0,0 +1,122 @@
+#include <cogl/cogl.h>
+
+#include "tests/cogl-test-utils.h"
+
+typedef CoglVertexP2C4 Vertex;
+
+static void
+setup_orthographic_modelview (void)
+{
+  graphene_matrix_t matrix;
+  int fb_width = cogl_framebuffer_get_width (test_fb);
+  int fb_height = cogl_framebuffer_get_height (test_fb);
+
+  /* Set up a non-identity modelview matrix. When the journal is
+   * flushed it will usually flush the identity matrix. Using the
+   * non-default matrix ensures that we test that Cogl restores the
+   * matrix we asked for. The matrix sets up an orthographic transform
+   * in the modelview matrix */
+
+  graphene_matrix_init_ortho (&matrix,
+                              0.f, fb_width,
+                              fb_height, 0.f,
+                              -1.f, 1.f);
+  cogl_framebuffer_set_modelview_matrix (test_fb, &matrix);
+}
+
+static void
+create_primitives (CoglPrimitive *primitives[2])
+{
+  static const Vertex vertex_data[8] =
+    {
+      /* triangle strip 1 */
+      {   0,   0, 255, 0, 0, 255 },
+      {   0, 100, 255, 0, 0, 255 },
+      { 100,   0, 255, 0, 0, 255 },
+      { 100, 100, 255, 0, 0, 255 },
+      /* triangle strip 2 */
+      { 200,   0, 0, 0, 255, 255 },
+      { 200, 100, 0, 0, 255, 255 },
+      { 300,   0, 0, 0, 255, 255 },
+      { 300, 100, 0, 0, 255, 255 },
+    };
+
+  primitives[0] = cogl_primitive_new_p2c4 (test_ctx,
+                                           COGL_VERTICES_MODE_TRIANGLE_STRIP,
+                                           G_N_ELEMENTS (vertex_data),
+                                           vertex_data);
+  cogl_primitive_set_n_vertices (primitives[0], 4);
+
+  primitives[1] = cogl_primitive_copy (primitives[0]);
+  cogl_primitive_set_first_vertex (primitives[1], 4);
+  cogl_primitive_set_n_vertices (primitives[1], 4);
+}
+
+static CoglPipeline *
+create_pipeline (void)
+{
+  CoglPipeline *pipeline = cogl_pipeline_new (test_ctx);
+
+  cogl_pipeline_set_color4ub (pipeline, 0, 255, 0, 255);
+
+  return pipeline;
+}
+
+static void
+test_primitive_and_journal (void)
+{
+  CoglPrimitive *primitives[2];
+  CoglPipeline *pipeline;
+
+  setup_orthographic_modelview ();
+  create_primitives (primitives);
+  pipeline = create_pipeline ();
+
+  /* Set a clip to clip all three rectangles to just the bottom half.
+   * The journal flushes its own clip state so this verifies that the
+   * clip state is correctly restored for the second primitive. */
+  cogl_framebuffer_push_rectangle_clip (test_fb,
+                                        0, 50, 300, 100);
+
+  cogl_primitive_draw (primitives[0], test_fb, pipeline);
+
+  /* Draw a rectangle using the journal in-between the two primitives.
+   * This should test that the journal gets flushed correctly and that
+   * the modelview matrix is restored. Half of the rectangle should be
+   * overridden by the second primitive */
+  cogl_framebuffer_draw_rectangle (test_fb,
+                                   pipeline,
+                                   100, 0, /* x1/y1 */
+                                   300, 100 /* x2/y2 */);
+
+  cogl_primitive_draw (primitives[1], test_fb, pipeline);
+
+  /* Check the three rectangles */
+  test_utils_check_region (test_fb,
+                           1, 51,
+                           98, 48,
+                           0xff0000ff);
+  test_utils_check_region (test_fb,
+                           101, 51,
+                           98, 48,
+                           0x00ff00ff);
+  test_utils_check_region (test_fb,
+                           201, 51,
+                           98, 48,
+                           0x0000ffff);
+
+  /* Check that the top half of all of the rectangles was clipped */
+  test_utils_check_region (test_fb,
+                           1, 1,
+                           298, 48,
+                           0x000000ff);
+
+  cogl_framebuffer_pop_clip (test_fb);
+
+  if (cogl_test_verbose ())
+    g_print ("OK\n");
+}
+
+COGL_TEST_SUITE (
+  g_test_add_func ("/primitive-and-journal", test_primitive_and_journal);
+)