Import of the watch repository from Pebble

tests/fw/graphics/test_blending.template.c

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+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "applib/graphics/graphics.h"
+#include "applib/graphics/framebuffer.h"
+#include "applib/graphics/bitblt_private.h"
+
+#include "applib/ui/window_private.h"
+#include "applib/ui/layer.h"
+
+#include "util/math.h"
+#include "util.h"
+
+#include "clar.h"
+
+#include <stdio.h>
+
+// Helper Functions
+////////////////////////////////////
+#include "test_graphics.h"
+#include "${BIT_DEPTH_NAME}/test_framebuffer.h"
+
+// Stubs
+////////////////////////////////////
+#include "graphics_common_stubs.h"
+#include "stubs_applib_resource.h"
+
+// Tests
+////////////////////////////////////
+
+#define ORIGIN_RECT_NO_CLIP GRect(0, 0, 144, 168)
+#define OFFSET_X 9
+#define OFFSET_Y 20
+#define STRIPE_WIDTH 64
+#define STRIPE_HEIGHT 1
+
+void prv_test_plot_horizontal_line(GBitmap *framebuffer, GRect area, GColor color) {
+  int y = area.origin.y;
+  int x0 = area.origin.x;
+  int x1 = x0 + area.size.w;
+
+  if (y >= framebuffer->bounds.size.h || y < 0) {
+    return;
+  }
+
+  int16_t x_min = MAX(MIN(x0, x1), framebuffer->bounds.origin.x);
+  int16_t x_max = MIN(MAX(x0, x1), framebuffer->bounds.origin.x + framebuffer->bounds.size.w);
+
+  for (int i=x_min; i < x_max; i++) {
+#if SCREEN_COLOR_DEPTH_BITS == 8
+    GColor *output = (GColor*)framebuffer->addr + y * framebuffer->row_size_bytes + i;
+    //                                     src_col, dest_col
+    output->argb = gcolor_alpha_blend(color, (*output)).argb;
+#endif // SCREEN_COLOR_DEPTH_BITS == 8
+  }
+}
+
+void test_blending_${BIT_DEPTH_NAME}__photoshop(void) {
+
+  GContext ctx;
+  FrameBuffer *fb = malloc(sizeof(FrameBuffer));
+  framebuffer_init(fb, &(GSize) { DISP_COLS, DISP_ROWS });
+  test_graphics_context_init(&ctx, fb);
+  GBitmap *background_0_100 = get_gbitmap_from_pbi("blendtest_0_100_backdrop.pbi");
+  GBitmap *background_33_66 = get_gbitmap_from_pbi("blendtest_33_66_backdrop.pbi");
+
+  setup_test_aa_sw(&ctx, fb, ORIGIN_RECT_NO_CLIP, ORIGIN_RECT_NO_CLIP, false, 1);
+  graphics_draw_bitmap_in_rect(&ctx, background_0_100, &ORIGIN_RECT_NO_CLIP);
+
+#if SCREEN_COLOR_DEPTH_BITS == 8
+
+  // Sanity check
+  cl_check(gbitmap_pbi_eq(&ctx.dest_bitmap, "blendtest_0_100_backdrop.pbi"));
+
+  // 0% alpha channel blend test
+  uint8_t color = 0x0;
+  uint8_t alpha = 0x0;
+
+  setup_test_aa_sw(&ctx, fb, ORIGIN_RECT_NO_CLIP, ORIGIN_RECT_NO_CLIP, false, 1);
+  graphics_draw_bitmap_in_rect(&ctx, background_0_100, &ORIGIN_RECT_NO_CLIP);
+
+  for (int i=0; i < 64; i++) {
+    prv_test_plot_horizontal_line(&ctx.dest_bitmap,
+                                  GRect(OFFSET_X, OFFSET_Y + i, STRIPE_WIDTH, STRIPE_HEIGHT),
+                                  (GColor){.argb = color | alpha});
+    color++;
+  }
+
+  // 100% alpha channel blend test
+  color = 0x0;
+  alpha = 0xC0;
+
+  for (int i=64; i < 128; i++) {
+    prv_test_plot_horizontal_line(&ctx.dest_bitmap,
+                                  GRect(OFFSET_X, OFFSET_Y + i, STRIPE_WIDTH, STRIPE_HEIGHT),
+                                  (GColor){.argb = color | alpha});
+    color++;
+  }
+
+  // Compare the results
+  cl_check(gbitmap_pbi_eq(&ctx.dest_bitmap, "blendtest_0_100.pbi"));
+
+  // Reset canvas
+  setup_test_aa_sw(&ctx, fb, ORIGIN_RECT_NO_CLIP, ORIGIN_RECT_NO_CLIP, false, 1);
+  graphics_draw_bitmap_in_rect(&ctx, background_33_66, &ORIGIN_RECT_NO_CLIP);
+
+  // 33% alpha channel blend test
+  color = 0x0;
+  alpha = 0x40;
+
+  for (int i=0; i < 64; i++) {
+    prv_test_plot_horizontal_line(&ctx.dest_bitmap,
+                                  GRect(OFFSET_X, OFFSET_Y + i, STRIPE_WIDTH, STRIPE_HEIGHT),
+                                  (GColor){.argb = color | alpha});
+    color++;
+  }
+
+  // 66% alpha channel blend test
+  color = 0x0;
+  alpha = 0x80;
+
+  for (int i=64; i < 128; i++) {
+    prv_test_plot_horizontal_line(&ctx.dest_bitmap,
+                                  GRect(OFFSET_X, OFFSET_Y + i, STRIPE_WIDTH, STRIPE_HEIGHT),
+                                  (GColor){.argb = color | alpha});
+    color++;
+  }
+
+  // Compare the results
+  cl_check(gbitmap_pbi_eq(&ctx.dest_bitmap, "blendtest_33_66.pbi"));
+#endif
+
+
+  gbitmap_destroy(background_0_100);
+  gbitmap_destroy(background_33_66);
+  free(fb);
+}