tests/cogl: Migrate pipeline user matrix test

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

src/tests/cogl/conform/meson.build

@@ -6,6 +6,7 @@ cogl_tests = [
   'test-color-hsl',
   'test-backface-culling',
   'test-just-vertex-shader',
+  'test-pipeline-user-matrix',
 ]
 
 cogl_test_conformance_includes = [

src/tests/cogl/conform/test-pipeline-user-matrix.c

@@ -0,0 +1,147 @@
+#include <cogl/cogl.h>
+
+#include <string.h>
+
+#include "tests/cogl-test-utils.h"
+
+typedef struct _TestState
+{
+  int width;
+  int height;
+} TestState;
+
+static void
+validate_result (TestState *state)
+{
+  uint32_t *pixels, *p;
+  char *screen_pixel;
+  const char *intended_pixel = "#ffffff";
+
+  /* The textures are setup so that when added together with the
+     correct matrices then all of the pixels should be white. We can
+     verify this by reading back the entire stage */
+  pixels = g_malloc (state->width * state->height * 4);
+
+  cogl_framebuffer_read_pixels (test_fb, 0, 0, state->width, state->height,
+                                COGL_PIXEL_FORMAT_RGBA_8888_PRE,
+                                (uint8_t *)pixels);
+
+  for (p = pixels; p < pixels + state->width * state->height; p++)
+    {
+      screen_pixel = g_strdup_printf ("#%06x", GUINT32_FROM_BE (*p) >> 8);
+      g_assert_cmpstr (screen_pixel, ==, intended_pixel);
+      g_free (screen_pixel);
+    }
+}
+
+static void
+paint (TestState *state)
+{
+  /* This texture is painted mirrored around the x-axis */
+  uint8_t data0[] = {
+    0xff, 0x00, 0x00, /* red -> becomes bottom left */
+    0x00, 0xff, 0x00, /* green -> becomes bottom right */
+    0x00, 0x00, 0xff, /* blue -> becomes top left */
+    0xff, 0x00, 0xff  /* magenta -> becomes top right */
+  };
+  /* This texture is painted mirrored about the y-axis */
+  uint8_t data1[] = {
+    0x00, 0xff, 0x00, /* green -> becomes top right */
+    0xff, 0xff, 0x00, /* yellow -> becomes top left */
+    0xff, 0x00, 0xff, /* magenta -> becomes bottom right */
+    0x00, 0xff, 0xff  /* cyan -> becomes bottom left */
+  };
+  CoglTexture *tex0, *tex1;
+  CoglPipeline *pipeline;
+  graphene_matrix_t matrix;
+  GError *error = NULL;
+
+  cogl_framebuffer_orthographic (test_fb,
+                                 0, 0,
+                                 state->width,
+                                 state->height,
+                                 -1,
+                                 100);
+
+  cogl_framebuffer_clear4f (test_fb, COGL_BUFFER_BIT_COLOR, 0, 0, 0, 1);
+
+  graphene_matrix_init_identity (&matrix);
+  cogl_framebuffer_set_modelview_matrix (test_fb, &matrix);
+
+  tex0 = cogl_texture_2d_new_from_data (test_ctx,
+                                        2, 2,
+                                        COGL_PIXEL_FORMAT_RGB_888,
+                                        6,
+                                        data0,
+                                        &error);
+  g_assert_no_error (error);
+
+  tex1 = cogl_texture_2d_new_from_data (test_ctx,
+                                        2, 2,
+                                        COGL_PIXEL_FORMAT_RGB_888,
+                                        6,
+                                        data1,
+                                        &error);
+  g_assert_no_error (error);
+
+  pipeline = cogl_pipeline_new (test_ctx);
+
+  /* Set the two textures as layers */
+  cogl_pipeline_set_layer_texture (pipeline, 0, tex0);
+  cogl_pipeline_set_layer_filters (pipeline, 0,
+                                   COGL_PIPELINE_FILTER_NEAREST,
+                                   COGL_PIPELINE_FILTER_NEAREST);
+  cogl_pipeline_set_layer_texture (pipeline, 1, tex1);
+  cogl_pipeline_set_layer_filters (pipeline, 1,
+                                   COGL_PIPELINE_FILTER_NEAREST,
+                                   COGL_PIPELINE_FILTER_NEAREST);
+
+  /* Set a combine mode so that the two textures get added together */
+  if (!cogl_pipeline_set_layer_combine (pipeline, 1,
+					"RGBA=ADD(PREVIOUS, TEXTURE)",
+					&error))
+    {
+      g_warning ("Error setting blend string: %s", error->message);
+      g_assert_not_reached ();
+    }
+
+  /* Set a matrix on the first layer so that it will mirror about the y-axis */
+  graphene_matrix_init_scale (&matrix, 1.0f, -1.0f, 1.0f);
+  graphene_matrix_translate (&matrix,
+                             &GRAPHENE_POINT3D_INIT (0.0f, 1.0f, 0.0f));
+  cogl_pipeline_set_layer_matrix (pipeline, 0, &matrix);
+
+  /* Set a matrix on the second layer so that it will mirror about the x-axis */
+  graphene_matrix_init_scale (&matrix, -1.0f, 1.0f, 1.0f);
+  graphene_matrix_translate (&matrix,
+                             &GRAPHENE_POINT3D_INIT (1.0f, 0.0f, 0.0f));
+  cogl_pipeline_set_layer_matrix (pipeline, 1, &matrix);
+
+  cogl_framebuffer_draw_rectangle (test_fb,
+                                   pipeline,
+                                   0, 0,
+                                   state->width, state->height);
+
+  cogl_object_unref (tex1);
+  cogl_object_unref (tex0);
+  cogl_object_unref (pipeline);
+}
+
+static void
+test_pipeline_user_matrix (void)
+{
+  TestState state;
+
+  state.width = cogl_framebuffer_get_width (test_fb);
+  state.height = cogl_framebuffer_get_height (test_fb);
+
+  paint (&state);
+  validate_result (&state);
+
+  if (cogl_test_verbose ())
+    g_print ("OK\n");
+}
+
+COGL_TEST_SUITE (
+  g_test_add_func ("/pipeline/user-matrix", test_pipeline_user_matrix);
+)