//
// Copyright 2015 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//

// WebGLCompatibilityTest.cpp : Tests of the GL_ANGLE_webgl_compatibility extension.

#include "test_utils/ANGLETest.h"

#include "test_utils/gl_raii.h"

namespace angle
{

class WebGLCompatibilityTest : public ANGLETest
{
  protected:
    WebGLCompatibilityTest()
    {
        setWindowWidth(128);
        setWindowHeight(128);
        setConfigRedBits(8);
        setConfigGreenBits(8);
        setConfigBlueBits(8);
        setConfigAlphaBits(8);
        setWebGLCompatibilityEnabled(true);
    }

    void SetUp() override
    {
        ANGLETest::SetUp();
        glRequestExtensionANGLE = reinterpret_cast<PFNGLREQUESTEXTENSIONANGLEPROC>(
            eglGetProcAddress("glRequestExtensionANGLE"));
    }

    void TearDown() override { ANGLETest::TearDown(); }

    PFNGLREQUESTEXTENSIONANGLEPROC glRequestExtensionANGLE = nullptr;
};

// Context creation would fail if EGL_ANGLE_create_context_webgl_compatibility was not available so
// the GL extension should always be present
TEST_P(WebGLCompatibilityTest, ExtensionStringExposed)
{
    EXPECT_TRUE(extensionEnabled("GL_ANGLE_webgl_compatibility"));
}

// Verify that all extension entry points are available
TEST_P(WebGLCompatibilityTest, EntryPoints)
{
    if (extensionEnabled("GL_ANGLE_request_extension"))
    {
        EXPECT_NE(nullptr, eglGetProcAddress("glRequestExtensionANGLE"));
    }
}

// WebGL 1 allows GL_DEPTH_STENCIL_ATTACHMENT as a valid binding point.  Make sure it is usable,
// even in ES2 contexts.
TEST_P(WebGLCompatibilityTest, DepthStencilBindingPoint)
{
    GLRenderbuffer renderbuffer;
    glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer.get());
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, 32, 32);

    GLFramebuffer framebuffer;
    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                              renderbuffer.get());

    EXPECT_GL_NO_ERROR();
}

// Test that attempting to enable an extension that doesn't exist generates GL_INVALID_OPERATION
TEST_P(WebGLCompatibilityTest, EnableExtensionValidation)
{
    glRequestExtensionANGLE("invalid_extension_string");
    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
}

// Test enabling the GL_OES_element_index_uint extension
TEST_P(WebGLCompatibilityTest, EnableExtensionUintIndices)
{
    if (getClientMajorVersion() != 2)
    {
        // This test only works on ES2 where uint indices are not available by default
        return;
    }

    EXPECT_FALSE(extensionEnabled("GL_OES_element_index_uint"));

    GLBuffer indexBuffer;
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer.get());

    GLuint data[] = {0, 1, 2, 1, 3, 2};
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(data), data, GL_STATIC_DRAW);

    ANGLE_GL_PROGRAM(program, "void main() { gl_Position = vec4(0, 0, 0, 1); }",
                     "void main() { gl_FragColor = vec4(0, 1, 0, 1); }")
    glUseProgram(program.get());

    glDrawElements(GL_TRIANGLES, 2, GL_UNSIGNED_INT, nullptr);
    EXPECT_GL_ERROR(GL_INVALID_ENUM);

    if (extensionRequestable("GL_OES_element_index_uint"))
    {
        glRequestExtensionANGLE("GL_OES_element_index_uint");
        EXPECT_GL_NO_ERROR();
        EXPECT_TRUE(extensionEnabled("GL_OES_element_index_uint"));

        glDrawElements(GL_TRIANGLES, 2, GL_UNSIGNED_INT, nullptr);
        EXPECT_GL_NO_ERROR();
    }
}

// Verify that shaders are of a compatible spec when the extension is enabled.
TEST_P(WebGLCompatibilityTest, ExtensionCompilerSpec)
{
    EXPECT_TRUE(extensionEnabled("GL_ANGLE_webgl_compatibility"));

    // Use of reserved _webgl prefix should fail when the shader specification is for WebGL.
    const std::string &vert =
        "struct Foo {\n"
        "    int _webgl_bar;\n"
        "};\n"
        "void main()\n"
        "{\n"
        "    Foo foo = Foo(1);\n"
        "}";

    // Default fragement shader.
    const std::string &frag =
        "void main()\n"
        "{\n"
        "    gl_FragColor = vec4(1.0,0.0,0.0,1.0);\n"
        "}";

    GLuint program = CompileProgram(vert, frag);
    EXPECT_EQ(0u, program);
    glDeleteProgram(program);
}

// Test that client-side array buffers are forbidden in WebGL mode
TEST_P(WebGLCompatibilityTest, ForbidsClientSideArrayBuffer)
{
    const std::string &vert =
        "attribute vec3 a_pos;\n"
        "void main()\n"
        "{\n"
        "    gl_Position = vec4(a_pos, 1.0);\n"
        "}\n";

    const std::string &frag =
        "precision highp float;\n"
        "void main()\n"
        "{\n"
        "    gl_FragColor = vec4(1.0);\n"
        "}\n";

    ANGLE_GL_PROGRAM(program, vert, frag);

    GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
    ASSERT_NE(-1, posLocation);
    glUseProgram(program.get());

    const auto &vertices = GetQuadVertices();
    glVertexAttribPointer(posLocation, 3, GL_FLOAT, GL_FALSE, 0, vertices.data());
    glEnableVertexAttribArray(posLocation);

    ASSERT_GL_NO_ERROR();
    glDrawArrays(GL_TRIANGLES, 0, 6);
    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
}

// Test that client-side element array buffers are forbidden in WebGL mode
TEST_P(WebGLCompatibilityTest, ForbidsClientSideElementBuffer)
{
    const std::string &vert =
        "attribute vec3 a_pos;\n"
        "void main()\n"
        "{\n"
        "    gl_Position = vec4(a_pos, 1.0);\n"
        "}\n";

    const std::string &frag =
        "precision highp float;\n"
        "void main()\n"
        "{\n"
        "    gl_FragColor = vec4(1.0);\n"
        "}\n";

    ANGLE_GL_PROGRAM(program, vert, frag);

    GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
    ASSERT_NE(-1, posLocation);
    glUseProgram(program.get());

    const auto &vertices = GetQuadVertices();

    GLBuffer vertexBuffer;
    glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer.get());
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices[0]) * vertices.size(), vertices.data(),
                 GL_STATIC_DRAW);

    glVertexAttribPointer(posLocation, 3, GL_FLOAT, GL_FALSE, 0, 0);
    glEnableVertexAttribArray(posLocation);

    const GLubyte indices[] = {0, 1, 2, 3, 4, 5};

    ASSERT_GL_NO_ERROR();
    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_BYTE, indices);
    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
}

// Tests the WebGL requirement of having the same stencil mask, writemask and ref for fron and back
TEST_P(WebGLCompatibilityTest, RequiresSameStencilMaskAndRef)
{
    // Run the test in an FBO to make sure we have some stencil bits.
    GLRenderbuffer renderbuffer;
    glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer.get());
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, 32, 32);

    GLFramebuffer framebuffer;
    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                              renderbuffer.get());

    ANGLE_GL_PROGRAM(program, "void main() { gl_Position = vec4(0, 0, 0, 1); }",
                     "void main() { gl_FragColor = vec4(0, 1, 0, 1); }")
    glUseProgram(program.get());
    ASSERT_GL_NO_ERROR();

    // Having ref and mask the same for front and back is valid.
    glStencilMask(255);
    glStencilFunc(GL_ALWAYS, 0, 255);
    glDrawArrays(GL_TRIANGLES, 0, 6);
    ASSERT_GL_NO_ERROR();

    // Having a different front - back write mask generates an error.
    glStencilMaskSeparate(GL_FRONT, 1);
    glDrawArrays(GL_TRIANGLES, 0, 6);
    EXPECT_GL_ERROR(GL_INVALID_OPERATION);

    // Setting both write masks separately to the same value is valid.
    glStencilMaskSeparate(GL_BACK, 1);
    glDrawArrays(GL_TRIANGLES, 0, 6);
    ASSERT_GL_NO_ERROR();

    // Having a different stencil front - back mask generates an error
    glStencilFuncSeparate(GL_FRONT, GL_ALWAYS, 0, 1);
    glDrawArrays(GL_TRIANGLES, 0, 6);
    EXPECT_GL_ERROR(GL_INVALID_OPERATION);

    // Setting both masks separately to the same value is valid.
    glStencilFuncSeparate(GL_BACK, GL_ALWAYS, 0, 1);
    glDrawArrays(GL_TRIANGLES, 0, 6);
    ASSERT_GL_NO_ERROR();

    // Having a different stencil front - back reference generates an error
    glStencilFuncSeparate(GL_FRONT, GL_ALWAYS, 255, 1);
    glDrawArrays(GL_TRIANGLES, 0, 6);
    EXPECT_GL_ERROR(GL_INVALID_OPERATION);

    // Setting both references separately to the same value is valid.
    glStencilFuncSeparate(GL_BACK, GL_ALWAYS, 255, 1);
    glDrawArrays(GL_TRIANGLES, 0, 6);
    ASSERT_GL_NO_ERROR();

    // Using different stencil funcs, everything being equal is valid.
    glStencilFuncSeparate(GL_BACK, GL_NEVER, 255, 1);
    glDrawArrays(GL_TRIANGLES, 0, 6);
    ASSERT_GL_NO_ERROR();
}

// Test that GL_FIXED is forbidden
TEST_P(WebGLCompatibilityTest, ForbidsGLFixed)
{
    GLBuffer buffer;
    glBindBuffer(GL_ARRAY_BUFFER, buffer.get());
    glBufferData(GL_ARRAY_BUFFER, 16, nullptr, GL_STATIC_DRAW);

    glVertexAttribPointer(0, 1, GL_FLOAT, GL_FALSE, 0, nullptr);
    ASSERT_GL_NO_ERROR();

    glVertexAttribPointer(0, 1, GL_FIXED, GL_FALSE, 0, nullptr);
    EXPECT_GL_ERROR(GL_INVALID_ENUM);
}

// Test the WebGL limit of 255 for the attribute stride
TEST_P(WebGLCompatibilityTest, MaxStride)
{
    GLBuffer buffer;
    glBindBuffer(GL_ARRAY_BUFFER, buffer.get());
    glBufferData(GL_ARRAY_BUFFER, 1024, nullptr, GL_STATIC_DRAW);

    glVertexAttribPointer(0, 1, GL_UNSIGNED_BYTE, GL_FALSE, 255, nullptr);
    ASSERT_GL_NO_ERROR();

    glVertexAttribPointer(0, 1, GL_UNSIGNED_BYTE, GL_FALSE, 256, nullptr);
    EXPECT_GL_ERROR(GL_INVALID_VALUE);
}

// Use this to select which configurations (e.g. which renderer, which GLES major version) these
// tests should be run against.
ANGLE_INSTANTIATE_TEST(WebGLCompatibilityTest,
                       ES2_D3D9(),
                       ES2_D3D11(),
                       ES3_D3D11(),
                       ES2_D3D11_FL9_3(),
                       ES2_OPENGL(),
                       ES3_OPENGL(),
                       ES2_OPENGLES(),
                       ES3_OPENGLES());

}  // namespace
