/*-------------------------------------------------------------------------
 * drawElements Quality Program OpenGL ES 2.0 Module
 * -------------------------------------------------
 *
 * Copyright 2014 The Android Open Source Project
 *
 * 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.
 *
 *//*!
 * \file
 * \brief Shader return statement tests.
 *//*--------------------------------------------------------------------*/

#include "es2fShaderReturnTests.hpp"
#include "glsShaderRenderCase.hpp"
#include "tcuStringTemplate.hpp"

#include <map>
#include <sstream>
#include <string>

using tcu::StringTemplate;

using std::map;
using std::string;
using std::ostringstream;

using namespace glu;
using namespace deqp::gls;

namespace deqp
{
namespace gles2
{
namespace Functional
{

enum ReturnMode
{
	RETURNMODE_ALWAYS = 0,
	RETURNMODE_NEVER,
	RETURNMODE_DYNAMIC,

	RETURNMODE_LAST
};

enum RequireFlags
{
	REQUIRE_DYNAMIC_LOOPS = (1<<0),
};

// Evaluation functions
inline void evalReturnAlways	(ShaderEvalContext& c) { c.color.xyz() = c.coords.swizzle(0,1,2); }
inline void evalReturnNever		(ShaderEvalContext& c) { c.color.xyz() = c.coords.swizzle(3,2,1); }
inline void evalReturnDynamic	(ShaderEvalContext& c) { c.color.xyz() = (c.coords.x()+c.coords.y() >= 0.0f) ? c.coords.swizzle(0,1,2) : c.coords.swizzle(3,2,1); }

static ShaderEvalFunc getEvalFunc (ReturnMode mode)
{
	switch (mode)
	{
		case RETURNMODE_ALWAYS:		return evalReturnAlways;
		case RETURNMODE_NEVER:		return evalReturnNever;
		case RETURNMODE_DYNAMIC:	return evalReturnDynamic;
		default:
			DE_ASSERT(DE_FALSE);
			return (ShaderEvalFunc)DE_NULL;
	}
}

class ShaderReturnCase : public ShaderRenderCase
{
public:
						ShaderReturnCase			(Context& context, const char* name, const char* description, bool isVertexCase, const char* shaderSource, ShaderEvalFunc evalFunc, deUint32 requirements = 0);
	virtual				~ShaderReturnCase			(void);

	void				init						(void);

private:
	const deUint32		m_requirements;
};

ShaderReturnCase::ShaderReturnCase (Context& context, const char* name, const char* description, bool isVertexCase, const char* shaderSource, ShaderEvalFunc evalFunc, deUint32 requirements)
	: ShaderRenderCase	(context.getTestContext(), context.getRenderContext(), context.getContextInfo(), name, description, isVertexCase, evalFunc)
	, m_requirements	(requirements)
{
	if (isVertexCase)
	{
		m_vertShaderSource = shaderSource;
		m_fragShaderSource =
			"varying mediump vec4 v_color;\n\n"
			"void main (void)\n"
			"{\n"
			"    gl_FragColor = v_color;\n"
			"}\n";
	}
	else
	{
		m_fragShaderSource = shaderSource;
		m_vertShaderSource =
			"attribute highp   vec4 a_position;\n"
			"attribute highp   vec4 a_coords;\n"
			"varying   mediump vec4 v_coords;\n\n"
			"void main (void)\n"
			"{\n"
			"    gl_Position = a_position;\n"
			"    v_coords = a_coords;\n"
			"}\n";
	}
}

ShaderReturnCase::~ShaderReturnCase (void)
{
}

void ShaderReturnCase::init (void)
{
	try
	{
		ShaderRenderCase::init();
	}
	catch (const CompileFailed&)
	{
		if (m_requirements & REQUIRE_DYNAMIC_LOOPS)
		{
			const bool isSupported = m_isVertexCase ? m_ctxInfo.isVertexDynamicLoopSupported() : m_ctxInfo.isFragmentDynamicLoopSupported();
			if (!isSupported)
				throw tcu::NotSupportedError("Dynamic loops not supported");
		}

		throw;
	}
}

ShaderReturnTests::ShaderReturnTests (Context& context)
	: TestCaseGroup(context, "return", "Return Statement Tests")
{
}

ShaderReturnTests::~ShaderReturnTests (void)
{
}

ShaderReturnCase* makeConditionalReturnInFuncCase (Context& context, const char* name, const char* description, ReturnMode returnMode, bool isVertex)
{
	// Template
	StringTemplate tmpl(
		"${COORDSTORAGE} ${COORDPREC} vec4 ${COORDS};\n"
		"${EXTRADECL}\n"
		"${COORDPREC} vec4 getColor (void)\n"
		"{\n"
		"    if (${RETURNCOND})\n"
		"        return vec4(${COORDS}.xyz, 1.0);\n"
		"    return vec4(${COORDS}.wzy, 1.0);\n"
		"}\n\n"
		"void main (void)\n"
		"{\n"
		"${POSITIONWRITE}"
		"    ${OUTPUT} = getColor();\n"
		"}\n");

	const char* coords = isVertex ? "a_coords" : "v_coords";

	map<string, string> params;

	params["COORDSTORAGE"]	= isVertex ? "attribute"	: "varying";
	params["COORDPREC"]		= isVertex ? "highp"		: "mediump";
	params["OUTPUT"]		= isVertex ? "v_color"		: "gl_FragColor";
	params["COORDS"]		= coords;
	params["EXTRADECL"]		= isVertex ? "attribute highp vec4 a_position;\nvarying mediump vec4 v_color;\n" : "";
	params["POSITIONWRITE"]	= isVertex ? "    gl_Position = a_position;\n" : "";

	switch (returnMode)
	{
		case RETURNMODE_ALWAYS:		params["RETURNCOND"] = "true";											break;
		case RETURNMODE_NEVER:		params["RETURNCOND"] = "false";											break;
		case RETURNMODE_DYNAMIC:	params["RETURNCOND"] = string(coords) + ".x+" + coords + ".y >= 0.0";	break;
		default:					DE_ASSERT(DE_FALSE);
	}

	return new ShaderReturnCase(context, name, description, isVertex, tmpl.specialize(params).c_str(), getEvalFunc(returnMode));
}

ShaderReturnCase* makeOutputWriteReturnCase (Context& context, const char* name, const char* description, bool inFunction, ReturnMode returnMode, bool isVertex)
{
	// Template
	StringTemplate tmpl(
		inFunction
		?
			"${COORDATTRS} vec4 ${COORDS};\n"
			"${EXTRADECL}\n"
			"void myfunc (void)\n"
			"{\n"
			"    ${OUTPUT} = vec4(${COORDS}.xyz, 1.0);\n"
			"    if (${RETURNCOND})\n"
			"        return;\n"
			"    ${OUTPUT} = vec4(${COORDS}.wzy, 1.0);\n"
			"}\n\n"
			"void main (void)\n"
			"{\n"
			"${POSITIONWRITE}"
			"    myfunc();\n"
			"}\n"
		:
			"${COORDATTRS} vec4 ${COORDS};\n"
			"uniform mediump int ui_one;\n"
			"${EXTRADECL}\n"
			"void main ()\n"
			"{\n"
			"${POSITIONWRITE}"
			"    ${OUTPUT} = vec4(${COORDS}.xyz, 1.0);\n"
			"    if (${RETURNCOND})\n"
			"        return;\n"
			"    ${OUTPUT} = vec4(${COORDS}.wzy, 1.0);\n"
			"}\n");

	const char* coords = isVertex ? "a_coords" : "v_coords";

	map<string, string> params;

	params["COORDATTRS"]	= isVertex ? "attribute highp"	: "varying mediump";
	params["COORDS"]		= coords;
	params["OUTPUT"]		= isVertex ? "v_color"			: "gl_FragColor";
	params["EXTRADECL"]		= isVertex ? "attribute highp vec4 a_position;\nvarying mediump vec4 v_color;\n" : "";
	params["POSITIONWRITE"]	= isVertex ? "    gl_Position = a_position;\n" : "";

	switch (returnMode)
	{
		case RETURNMODE_ALWAYS:		params["RETURNCOND"] = "true";											break;
		case RETURNMODE_NEVER:		params["RETURNCOND"] = "false";											break;
		case RETURNMODE_DYNAMIC:	params["RETURNCOND"] = string(coords) + ".x+" + coords + ".y >= 0.0";	break;
		default:					DE_ASSERT(DE_FALSE);
	}

	return new ShaderReturnCase(context, name, description, isVertex, tmpl.specialize(params).c_str(), getEvalFunc(returnMode));
}

ShaderReturnCase* makeReturnInLoopCase (Context& context, const char* name, const char* description, bool isDynamicLoop, ReturnMode returnMode, bool isVertex)
{
	// Template
	StringTemplate tmpl(
		"${COORDSTORAGE} ${COORDPREC} vec4 ${COORDS};\n"
		"uniform mediump int ui_one;\n"
		"${EXTRADECL}\n"
		"${COORDPREC} vec4 getCoords (void)\n"
		"{\n"
		"    ${COORDPREC} vec4 coords = ${COORDS};\n"
		"    for (int i = 0; i < ${ITERLIMIT}; i++)\n"
		"    {\n"
		"        if (${RETURNCOND})\n"
		"            return coords;\n"
		"        coords = coords.wzyx;\n"
		"    }\n"
		"    return coords;\n"
		"}\n\n"
		"void main (void)\n"
		"{\n"
		"${POSITIONWRITE}"
		"    ${OUTPUT} = vec4(getCoords().xyz, 1.0);\n"
		"}\n");

	const char* coords = isVertex ? "a_coords" : "v_coords";

	map<string, string> params;

	params["COORDSTORAGE"]	= isVertex ? "attribute"	: "varying";
	params["COORDPREC"]		= isVertex ? "highp"		: "mediump";
	params["OUTPUT"]		= isVertex ? "v_color"		: "gl_FragColor";
	params["COORDS"]		= coords;
	params["EXTRADECL"]		= isVertex ? "attribute highp vec4 a_position;\nvarying mediump vec4 v_color;\n" : "";
	params["POSITIONWRITE"]	= isVertex ? "    gl_Position = a_position;\n" : "";
	params["ITERLIMIT"]		= isDynamicLoop ? "ui_one" : "1";

	switch (returnMode)
	{
		case RETURNMODE_ALWAYS:		params["RETURNCOND"] = "true";											break;
		case RETURNMODE_NEVER:		params["RETURNCOND"] = "false";											break;
		case RETURNMODE_DYNAMIC:	params["RETURNCOND"] = string(coords) + ".x+" + coords + ".y >= 0.0";	break;
		default:					DE_ASSERT(DE_FALSE);
	}

	return new ShaderReturnCase(context, name, description, isVertex, tmpl.specialize(params).c_str(), getEvalFunc(returnMode), isDynamicLoop ? REQUIRE_DYNAMIC_LOOPS : 0);
}

static const char* getReturnModeName (ReturnMode mode)
{
	switch (mode)
	{
		case RETURNMODE_ALWAYS:		return "always";
		case RETURNMODE_NEVER:		return "never";
		case RETURNMODE_DYNAMIC:	return "dynamic";
		default:
			DE_ASSERT(DE_FALSE);
			return DE_NULL;
	}
}

static const char* getReturnModeDesc (ReturnMode mode)
{
	switch (mode)
	{
		case RETURNMODE_ALWAYS:		return "Always return";
		case RETURNMODE_NEVER:		return "Never return";
		case RETURNMODE_DYNAMIC:	return "Return based on coords";
		default:
			DE_ASSERT(DE_FALSE);
			return DE_NULL;
	}
}

void ShaderReturnTests::init (void)
{
	// Single return statement in function.
	addChild(new ShaderReturnCase(m_context, "single_return_vertex", "Single return statement in function", true,
		"attribute highp vec4 a_position;\n"
		"attribute highp vec4 a_coords;\n"
		"varying highp vec4 v_color;\n\n"
		"vec4 getColor (void)\n"
		"{\n"
		"    return vec4(a_coords.xyz, 1.0);\n"
		"}\n\n"
		"void main (void)\n"
		"{\n"
		"    gl_Position = a_position;\n"
		"    v_color = getColor();\n"
		"}\n", evalReturnAlways));
	addChild(new ShaderReturnCase(m_context, "single_return_fragment", "Single return statement in function", false,
		"varying mediump vec4 v_coords;\n"
		"mediump vec4 getColor (void)\n"
		"{\n"
		"    return vec4(v_coords.xyz, 1.0);\n"
		"}\n\n"
		"void main (void)\n"
		"{\n"
		"    gl_FragColor = getColor();\n"
		"}\n", evalReturnAlways));

	// Conditional return statement in function.
	for (int returnMode = 0; returnMode < RETURNMODE_LAST; returnMode++)
	{
		for (int isFragment = 0; isFragment < 2; isFragment++)
		{
			string name			= string("conditional_return_") + getReturnModeName((ReturnMode)returnMode) + (isFragment ? "_fragment" : "_vertex");
			string description	= string(getReturnModeDesc((ReturnMode)returnMode)) + " in function";
			addChild(makeConditionalReturnInFuncCase(m_context, name.c_str(), description.c_str(), (ReturnMode)returnMode, isFragment == 0));
		}
	}

	// Unconditional double return in function.
	addChild(new ShaderReturnCase(m_context, "double_return_vertex", "Unconditional double return in function", true,
		"attribute highp vec4 a_position;\n"
		"attribute highp vec4 a_coords;\n"
		"varying highp vec4 v_color;\n\n"
		"vec4 getColor (void)\n"
		"{\n"
		"    return vec4(a_coords.xyz, 1.0);\n"
		"    return vec4(a_coords.wzy, 1.0);\n"
		"}\n\n"
		"void main (void)\n"
		"{\n"
		"    gl_Position = a_position;\n"
		"    v_color = getColor();\n"
		"}\n", evalReturnAlways));
	addChild(new ShaderReturnCase(m_context, "double_return_fragment", "Unconditional double return in function", false,
		"varying mediump vec4 v_coords;\n"
		"mediump vec4 getColor (void)\n"
		"{\n"
		"    return vec4(v_coords.xyz, 1.0);\n"
		"    return vec4(v_coords.wzy, 1.0);\n"
		"}\n\n"
		"void main (void)\n"
		"{\n"
		"    gl_FragColor = getColor();\n"
		"}\n", evalReturnAlways));

	// Last statement in main.
	addChild(new ShaderReturnCase(m_context, "last_statement_in_main_vertex", "Return as a final statement in main()", true,
		"attribute highp vec4 a_position;\n"
		"attribute highp vec4 a_coords;\n"
		"varying highp vec4 v_color;\n\n"
		"void main (void)\n"
		"{\n"
		"    gl_Position = a_position;\n"
		"    v_color = vec4(a_coords.xyz, 1.0);\n"
		"    return;\n"
		"}\n", evalReturnAlways));
	addChild(new ShaderReturnCase(m_context, "last_statement_in_main_fragment", "Return as a final statement in main()", false,
		"varying mediump vec4 v_coords;\n\n"
		"void main (void)\n"
		"{\n"
		"    gl_FragColor = vec4(v_coords.xyz, 1.0);\n"
		"    return;\n"
		"}\n", evalReturnAlways));

	// Return between output variable writes.
	for (int inFunc = 0; inFunc < 2; inFunc++)
	{
		for (int returnMode = 0; returnMode < RETURNMODE_LAST; returnMode++)
		{
			for (int isFragment = 0; isFragment < 2; isFragment++)
			{
				string name = string("output_write_") + (inFunc ? "in_func_" : "") + getReturnModeName((ReturnMode)returnMode) + (isFragment ? "_fragment" : "_vertex");
				string desc = string(getReturnModeDesc((ReturnMode)returnMode)) + (inFunc ? " in user-defined function" : " in main()") + " between output writes";

				addChild(makeOutputWriteReturnCase(m_context, name.c_str(), desc.c_str(), inFunc != 0, (ReturnMode)returnMode, isFragment == 0));
			}
		}
	}

	// Conditional return statement in loop.
	for (int isDynamicLoop = 0; isDynamicLoop < 2; isDynamicLoop++)
	{
		for (int returnMode = 0; returnMode < RETURNMODE_LAST; returnMode++)
		{
			for (int isFragment = 0; isFragment < 2; isFragment++)
			{
				string name			= string("return_in_") + (isDynamicLoop ? "dynamic" : "static") + "_loop_" + getReturnModeName((ReturnMode)returnMode) + (isFragment ? "_fragment" : "_vertex");
				string description	= string(getReturnModeDesc((ReturnMode)returnMode)) + " in loop";
				addChild(makeReturnInLoopCase(m_context, name.c_str(), description.c_str(), isDynamicLoop != 0, (ReturnMode)returnMode, isFragment == 0));
			}
		}
	}

	// Unconditional return in infinite loop.
	addChild(new ShaderReturnCase(m_context, "return_in_infinite_loop_vertex", "Return in infinite loop", true,
		"attribute highp vec4 a_position;\n"
		"attribute highp vec4 a_coords;\n"
		"varying highp vec4 v_color;\n"
		"uniform int ui_zero;\n\n"
		"highp vec4 getCoords (void)\n"
		"{\n"
		"	for (int i = 1; i < 10; i += ui_zero)\n"
		"		return a_coords;\n"
		"	return a_coords.wzyx;\n"
		"}\n\n"
		"void main (void)\n"
		"{\n"
		"    gl_Position = a_position;\n"
		"    v_color = vec4(getCoords().xyz, 1.0);\n"
		"    return;\n"
		"}\n", evalReturnAlways, REQUIRE_DYNAMIC_LOOPS));
	addChild(new ShaderReturnCase(m_context, "return_in_infinite_loop_fragment", "Return in infinite loop", false,
		"varying mediump vec4 v_coords;\n"
		"uniform int ui_zero;\n\n"
		"mediump vec4 getCoords (void)\n"
		"{\n"
		"	for (int i = 1; i < 10; i += ui_zero)\n"
		"		return v_coords;\n"
		"	return v_coords.wzyx;\n"
		"}\n\n"
		"void main (void)\n"
		"{\n"
		"    gl_FragColor = vec4(getCoords().xyz, 1.0);\n"
		"    return;\n"
		"}\n", evalReturnAlways, REQUIRE_DYNAMIC_LOOPS));
}

} // Functional
} // gles2
} // deqp