cc: Add point-based UV coordinate on TextureLayer

cc/draw_quad_unittest.cc

Index: cc/draw_quad_unittest.cc
diff --git a/cc/draw_quad_unittest.cc b/cc/draw_quad_unittest.cc
index 0362418eea574b8a0ce32fb41cbe7577ab34cfcf..d6e8e92e8e8a4828b067d84c5db29d26d26f7cbe 100644
--- a/cc/draw_quad_unittest.cc
+++ b/cc/draw_quad_unittest.cc
@@ -362,29 +362,96 @@ TEST(DrawQuadTest, copyTextureDrawQuad)
     gfx::Rect opaqueRect(3, 7, 10, 12);
     unsigned resourceId = 82;
     bool premultipliedAlpha = true;
-    gfx::RectF uvRect(0.5f, 224.f, 51.f, 36.f);
+    gfx::PointF uvTopLeft(0.5f, 224.f);
+    gfx::PointF uvBottomRight(51.5f, 260.f);
     const float vertex_opacity[] = {1.0f, 1.0f, 1.0f, 1.0f};
     bool flipped = true;
     CREATE_SHARED_STATE();
 
-    CREATE_QUAD_6_NEW(TextureDrawQuad, opaqueRect, resourceId, premultipliedAlpha, uvRect, vertex_opacity, flipped);
+    CREATE_QUAD_7_NEW(TextureDrawQuad, opaqueRect, resourceId, premultipliedAlpha, uvTopLeft, uvBottomRight, vertex_opacity, flipped);
     EXPECT_EQ(DrawQuad::TEXTURE_CONTENT, copyQuad->material);
     EXPECT_RECT_EQ(opaqueRect, copyQuad->opaque_rect);
     EXPECT_EQ(resourceId, copyQuad->resource_id);
     EXPECT_EQ(premultipliedAlpha, copyQuad->premultiplied_alpha);
-    EXPECT_FLOAT_RECT_EQ(uvRect, copyQuad->uv_rect);
+    EXPECT_EQ(uvTopLeft, copyQuad->uv_top_left);
+    EXPECT_EQ(uvBottomRight, copyQuad->uv_bottom_right);
     EXPECT_FLOAT_ARRAY_EQ(vertex_opacity, copyQuad->vertex_opacity, 4);
     EXPECT_EQ(flipped, copyQuad->flipped);
 
-    CREATE_QUAD_5_ALL(TextureDrawQuad, resourceId, premultipliedAlpha, uvRect, vertex_opacity, flipped);
+    CREATE_QUAD_6_ALL(TextureDrawQuad, resourceId, premultipliedAlpha, uvTopLeft, uvBottomRight, vertex_opacity, flipped);
     EXPECT_EQ(DrawQuad::TEXTURE_CONTENT, copyQuad->material);
     EXPECT_EQ(resourceId, copyQuad->resource_id);
     EXPECT_EQ(premultipliedAlpha, copyQuad->premultiplied_alpha);
-    EXPECT_FLOAT_RECT_EQ(uvRect, copyQuad->uv_rect);
+    EXPECT_EQ(uvTopLeft, copyQuad->uv_top_left);
+    EXPECT_EQ(uvBottomRight, copyQuad->uv_bottom_right);
     EXPECT_FLOAT_ARRAY_EQ(vertex_opacity, copyQuad->vertex_opacity, 4);
     EXPECT_EQ(flipped, copyQuad->flipped);
 }
 
+TEST(DrawQuadTest, clipTextureDrawQuad)
+{
+    gfx::Rect opaqueRect(3, 7, 10, 12);
+    unsigned resourceId = 82;
+    bool premultipliedAlpha = true;
+    bool flipped = true;
+    CREATE_SHARED_STATE();
+    // Original quad is at (30, 40) size 50*60

[danakj, 2013/01/15 22:39:09]

nit: comments are complete sentences including period and capitalization.

[Jerome, 2013/01/15 23:14:35]

Done.

+    sharedState->content_to_target_transform = MathUtil::createGfxTransform(1.f, 0.f, 0.f, 1.f, 10.f, 20.f);
+    // after transform the quad is at (40, 60) size 50*60

[danakj, 2013/01/15 22:39:09]

nit: same thing

[Jerome, 2013/01/15 23:14:35]

Done.

+    sharedState->clip_rect = gfx::Rect(50, 70, 30, 20);
+
+    //40 50       90
+    // B--:-------C 60
+    // |  b----c -|-70
+    // |  |    |  |
+    // |  a----d -|-90
+    // |          |
+    // A----------D 120
+    // UV and vertex opacity are stored per vertex on the parent rectangle 'ABCD'.
+    // The value on the clipped rectangle 'abcd' are interpolated to keep visual appearance.
+
+    // UV value for 'B' vertex

[danakj, 2013/01/15 22:39:09]

nit: complete sentences for all these please.

[Jerome, 2013/01/15 23:14:35]

Done.

+    gfx::PointF uvTopLeft(0.1f, 0.2f);
+    // UV value for 'D' vertex
+    gfx::PointF uvBottomRight(0.9f, 0.8f);
+    // Vertex opacity for 'ABCD'
+    const float vertexOpacity[] = {0.3f, 0.4f, 0.7f, 0.8f};
+
+    {
+      CREATE_QUAD_7_NEW(TextureDrawQuad, opaqueRect, resourceId, premultipliedAlpha, uvTopLeft, uvBottomRight, vertexOpacity, flipped);
+      CREATE_QUAD_6_ALL(TextureDrawQuad, resourceId, premultipliedAlpha, uvTopLeft, uvBottomRight, vertexOpacity, flipped);
+      EXPECT_TRUE(quadAll->PerformClipping());
+
+      // UV value for vertex 'b'
+      gfx::PointF uvTopLeftClipped(0.26f, 0.3f);

[danakj, 2013/01/15 22:39:09]

I was thinking more about describing these expected values, rather than the
inputs - though the inputs will be very helpful in understanding the description
of these expected outputs. Like:

// This is A - B + D^2
// 0.5 - 0.6 + 0.2^2 = 0.26

[Jerome, 2013/01/15 23:14:35]

Done.

+      // UV value for vertex 'd'
+      gfx::PointF uvBottomRightClipped(0.74f, 0.5f);
+      // Vertex opacity for 'abcd'
+      const float vertexOpacityClipped[] = {0.43f, 0.45f, 0.65f, 0.67f};
+
+      EXPECT_EQ(uvTopLeftClipped, quadAll->uv_top_left);
+      EXPECT_EQ(uvBottomRightClipped, quadAll->uv_bottom_right);
+      EXPECT_FLOAT_ARRAY_EQ(vertexOpacityClipped, quadAll->vertex_opacity, 4);
+    }
+
+    uvTopLeft = gfx::PointF(0.8f, 0.7f);
+    uvBottomRight = gfx::PointF(0.2f, 0.1f);
+
+    {
+      CREATE_QUAD_7_NEW(TextureDrawQuad, opaqueRect, resourceId, premultipliedAlpha, uvTopLeft, uvBottomRight, vertexOpacity, flipped);
+      CREATE_QUAD_6_ALL(TextureDrawQuad, resourceId, premultipliedAlpha, uvTopLeft, uvBottomRight, vertexOpacity, flipped);
+      EXPECT_TRUE(quadAll->PerformClipping());
+
+      // UV value for vertex 'b'
+      gfx::PointF uvTopLeftClipped(0.68f, 0.6f);
+      // UV value for vertex 'd'
+      gfx::PointF uvBottomRightClipped(0.32f, 0.4f);
+
+      EXPECT_EQ(uvTopLeftClipped, quadAll->uv_top_left);
+      EXPECT_EQ(uvBottomRightClipped, quadAll->uv_bottom_right);
+    }
+}
+
 TEST(DrawQuadTest, copyTileDrawQuad)
 {
     gfx::Rect opaqueRect(33, 44, 22, 33);