//
// Urho3D Engine
// Copyright (c) 2008-2011 Lasse Öörni
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

#pragma once

#include "Color.h"
#include "HashMap.h"
#include "Object.h"
#include "Rect.h"
#include "GraphicsDefs.h"

class Image;
class IndexBuffer;
class Matrix3;
class Matrix4;
class Matrix3x4;
class GPUObject;
class GraphicsImpl;
class RenderSurface;
class ShaderVariation;
class Texture;
class Texture2D;
class TextureCube;
class Vector3;
class Vector4;
class VertexBuffer;
class VertexDeclaration;

struct ShaderParameter;

static const unsigned NUM_QUERIES = 2;

/// %Graphics subsystem. Manages the application window, rendering state and GPU resources.
class Graphics : public Object
{
    OBJECT(Graphics);
    
public:
    /// Construct.
    Graphics(Context* context);
    /// Destruct. Close the window and release the Direct3D9 device .
    virtual ~Graphics();
    
    /// %Set window title.
    void SetWindowTitle(const String& windowTitle);
    /// %Set screen mode.
    bool SetMode(int width, int height, bool fullscreen, bool vsync, bool tripleBuffer, int multiSample);
    /// %Set screen resolution only.
    bool SetMode(int width, int height);
    /// Toggle between full screen and windowed mode.
    bool ToggleFullscreen();
    /// Close the window.
    void Close();
    /// Take a screenshot.
    bool TakeScreenShot(Image& destImage);
    /// %Set whether to flush GPU command queue at the end of each frame. Default true.
    void SetFlushGPU(bool enable);
    
    /// Begin frame rendering.
    bool BeginFrame();
    /// End frame rendering and swap buffers.
    void EndFrame();
    /// Clear any or all of render target, depth buffer and stencil buffer.
    void Clear(unsigned flags, const Color& color = Color(0.0f, 0.0f, 0.0f, 0.0f), float depth = 1.0f, unsigned stencil = 0);
    /// Draw non-indexed geometry.
    void Draw(PrimitiveType type, unsigned vertexStart, unsigned vertexCount);
    /// Draw indexed geometry.
    void Draw(PrimitiveType type, unsigned indexStart, unsigned indexCount, unsigned minVertex, unsigned vertexCount);
    /// Draw indexed, instanced geometry. An instancing vertex buffer must be set.
    void DrawInstanced(PrimitiveType type, unsigned indexStart, unsigned indexCount, unsigned minVertex, unsigned vertexCount, unsigned instanceCount);
    /// %Set vertex buffer.
    void SetVertexBuffer(VertexBuffer* buffer);
    /// %Set multiple vertex buffers.
    bool SetVertexBuffers(const Vector<VertexBuffer*>& buffers, const PODVector<unsigned>& elementMasks, unsigned instanceOffset = 0);
    /// %Set multiple vertex buffers.
    bool SetVertexBuffers(const Vector<SharedPtr<VertexBuffer> >& buffers, const PODVector<unsigned>& elementMasks, unsigned instanceOffset = 0);
    /// %Set index buffer.
    void SetIndexBuffer(IndexBuffer* buffer);
    /// %Set shaders.
    void SetShaders(ShaderVariation* vs, ShaderVariation* ps);
    /// %Set shader float constants.
    void SetShaderParameter(StringHash param, const float* data, unsigned count);
    /// %Set shader float constant.
    void SetShaderParameter(StringHash param, float value);
    /// %Set shader color constant.
    void SetShaderParameter(StringHash param, const Color& color);
    /// %Set shader 3x3 matrix constant.
    void SetShaderParameter(StringHash param, const Matrix3& matrix);
    /// %Set shader 3D vector constant.
    void SetShaderParameter(StringHash param, const Vector3& vector);
    /// %Set shader 4x4 matrix constant.
    void SetShaderParameter(StringHash param, const Matrix4& matrix);
    /// %Set shader 4D vector constant.
    void SetShaderParameter(StringHash param, const Vector4& vector);
    /// %Set shader 3x4 matrix constant.
    void SetShaderParameter(StringHash param, const Matrix3x4& matrix);
    /// Register a shader parameter globally. Called by Shader.
    void RegisterShaderParameter(StringHash param, const ShaderParameter& definition);
    /// Check whether a shader parameter in the currently set shaders needs update.
    bool NeedParameterUpdate(StringHash param, const void* source);
    /// Check whether the current pixel shader uses a texture unit.
    bool NeedTextureUnit(TextureUnit unit);
    /// Clear remembered shader parameter sources.
    void ClearParameterSources();
    /// Clear remembered transform shader parameter sources.
    void ClearTransformSources();
    /// %Set texture.
    void SetTexture(unsigned index, Texture* texture);
    /// %Set default texture filtering mode.
    void SetDefaultTextureFilterMode(TextureFilterMode mode);
    /// %Set texture anisotropy.
    void SetTextureAnisotropy(unsigned level);
    /// Reset all render targets and depth stencil buffer (render to back buffer.)
    void ResetRenderTargets();
    /// Reset specific render target.
    void ResetRenderTarget(unsigned index);
    /// Reset depth stencil buffer.
    void ResetDepthStencil();
    /// %Set render target.
    void SetRenderTarget(unsigned index, RenderSurface* renderTarget);
    /// %Set render target.
    void SetRenderTarget(unsigned index, Texture2D* renderTexture);
    /// %Set depth stencil buffer.
    void SetDepthStencil(RenderSurface* depthStencil);
    /// %Set depth stencil buffer.
    void SetDepthStencil(Texture2D* depthTexture);
    /// %Set viewport.
    void SetViewport(const IntRect& rect);
    /// %Set alpha test.
    void SetAlphaTest(bool enable, CompareMode mode = CMP_ALWAYS, float alphaRef = 0.5f);
    /// %Set blending mode.
    void SetBlendMode(BlendMode mode);
    /// %Set color write on/off.
    void SetColorWrite(bool enable);
    /// %Set hardware culling mode.
    void SetCullMode(CullMode mode);
    /// %Set depth bias.
    void SetDepthBias(float constantBias, float slopeScaledBias);
    /// %Set depth compare.
    void SetDepthTest(CompareMode mode);
    /// %Set depth write on/off.
    void SetDepthWrite(bool enable);
    /// %Set polygon fill mode.
    void SetFillMode(FillMode mode);
    /// %Set scissor test.
    void SetScissorTest(bool enable, const Rect& rect = Rect::FULL, bool borderInclusive = true);
    /// %Set scissor test.
    void SetScissorTest(bool enable, const IntRect& rect);
    /// %Set stencil test.
    void SetStencilTest(bool enable, CompareMode mode = CMP_ALWAYS, StencilOp pass = OP_KEEP, StencilOp fail = OP_KEEP, StencilOp zFail = OP_KEEP, unsigned stencilRef = 0, unsigned stencilMask = M_MAX_UNSIGNED);
    /// %Set vertex buffer stream frequency.
    void SetStreamFrequency(unsigned index, unsigned frequency);
    /// Reset stream frequencies.
    void ResetStreamFrequencies();
    /// %Set force Shader Model 2 flag.
    void SetForceSM2(bool enable);
    /// %Set force fallback shaders flag.
    void SetForceFallback(bool enable);
    
    /// Return whether rendering initialized.
    bool IsInitialized() const;
    /// Return graphics implementation, which holds the actual API-specific resources.
    GraphicsImpl* GetImpl() const { return impl_; }
    /// Return window title.
    const String& GetWindowTitle() const { return windowTitle_; }
    /// Return window width.
    int GetWidth() const { return width_; }
    /// Return window height.
    int GetHeight() const { return height_; }
    /// Return multisample mode (1 = no multisampling.)
    int GetMultiSample() const { return multiSample_; }
    /// Return whether window is fullscreen.
    bool GetFullscreen() const { return fullscreen_; }
    /// Return whether vertical sync is on.
    bool GetVSync() const { return vsync_; }
    /// Return whether triple buffering is enabled.
    bool GetTripleBuffer() const { return tripleBuffer_; }
    /// Return whether GPU command queue is flushed at the end of each frame.
    bool GetFlushGPU() const { return flushGPU_; }
    /// Return whether Direct3D device is lost, and can not yet render. This happens during fullscreen resolution switching.
    bool IsDeviceLost() const { return deviceLost_; }
    /// Return window handle.
    unsigned GetWindowHandle() const;
    /// Return number of primitives drawn this frame.
    unsigned GetNumPrimitives() const { return numPrimitives_; }
    /// Return number of batches drawn this frame.
    unsigned GetNumBatches() const { return numBatches_; }
    /// Return dummy color texture format for shadow maps. Is "NULL" (consume no video memory) if supported.
    unsigned GetDummyColorFormat() const { return dummyColorFormat_; }
    /// Return shadow map depth texture format, or 0 if not supported.
    unsigned GetShadowMapFormat() const { return shadowMapFormat_; }
    /// Return 24-bit shadow map depth texture format, or 0 if not supported.
    unsigned GetHiresShadowMapFormat() const { return hiresShadowMapFormat_; }
    /// Return whether texture render targets are supported. Always true on Direct3D9
    bool GetRenderTargetSupport() const { return true; }
    /// Return whether fallback shaders are required.
    bool GetFallback() const { return fallback_; }
    /// Return whether Shader Model 3 is supported.
    bool GetSM3Support() const { return hasSM3_; }
    /// Return whether hardware depth can be read as a texture.
    bool GetHardwareDepthSupport() const { return hardwareDepthSupport_; }
    /// Return whether shadow map depth compare is done in hardware.
    bool GetHardwareShadowSupport() const { return hardwareShadowSupport_; }
    /// Return whether 24-bit shadow maps are supported.
    bool GetHiresShadowSupport() const { return hiresShadowSupport_; }
    /// Return whether stream offset is supported.
    bool GetStreamOffsetSupport() const { return streamOffsetSupport_; }
    /// Return supported fullscreen resolutions.
    PODVector<IntVector2> GetResolutions() const;
    /// Return supported multisampling levels.
    PODVector<int> GetMultiSampleLevels() const;
    /// Return vertex buffer by index.
    VertexBuffer* GetVertexBuffer(unsigned index) const;
    /// Return current index buffer.
    IndexBuffer* GetIndexBuffer() const { return indexBuffer_; }
    /// Return current vertex declaration.
    VertexDeclaration* GetVertexDeclaration() const { return vertexDeclaration_; }
    /// Return current vertex shader.
    ShaderVariation* GetVertexShader() const { return vertexShader_; }
    /// Return current pixel shader.
    ShaderVariation* GetPixelShader() const { return pixelShader_; }
    /// Return texture unit index by name.
    TextureUnit GetTextureUnit(const String& name);
    /// Return current texture by texture unit index.
    Texture* GetTexture(unsigned index) const;
    /// Return default texture filtering mode.
    TextureFilterMode GetDefaultTextureFilterMode() const { return defaultTextureFilterMode_; }
    /// Return current render target by index.
    RenderSurface* GetRenderTarget(unsigned index) const;
    /// Return current depth stencil buffer.
    RenderSurface* GetDepthStencil() const { return depthStencil_; }
    /// Return backbuffer depth stencil texture, created if available.
    Texture2D* GetDepthTexture() const;
    /// Return the viewport coordinates.
    IntRect GetViewport() const { return viewport_; }
    /// Return whether alpha testing is enabled.
    bool GetAlphaTest() const { return alphaTest_; }
    /// Return alpha test compare mode.
    CompareMode GetAlphaTestMode() const { return alphaTestMode_; }
    /// Return texture anisotropy.
    unsigned GetTextureAnisotropy() const { return textureAnisotropy_; }
    /// Return alpha test reference value.
    float GetAlphaRef() const { return alphaRef_; }
    /// Return blending mode.
    BlendMode GetBlendMode() const { return blendMode_; }
    /// Return whether color write is enabled.
    bool GetColorWrite() const { return colorWrite_; }
    /// Return hardware culling mode.
    CullMode GetCullMode() const { return cullMode_; }
    /// Return depth constant bias.
    float GetDepthConstantBias() const { return constantDepthBias_; }
    /// Return depth slope scaled bias.
    float GetDepthSlopeScaledBias() const { return slopeScaledDepthBias_; }
    /// Return depth compare mode.
    CompareMode GetDepthTest() const { return depthTestMode_; }
    /// Return whether depth write is enabled.
    bool GetDepthWrite() const { return depthWrite_; }
    /// Return polygon fill mode.
    FillMode GetFillMode() const { return fillMode_; }
    /// Return whether stencil test is enabled.
    bool GetStencilTest() const { return stencilTest_; }
    /// Return whether scissor test is enabled.
    bool GetScissorTest() const { return scissorTest_; }
    /// Return scissor rectangle coordinates.
    const IntRect& GetScissorRect() const { return scissorRect_; }
    /// Return stencil compare mode.
    CompareMode GetStencilTestMode() const { return stencilTestMode_; }
    /// Return stencil operation to do if stencil test passes.
    StencilOp GetStencilPass() const { return stencilPass_; }
    /// Return stencil operation to do if stencil test fails.
    StencilOp GetStencilFail() const { return stencilFail_; }
    /// Return stencil operation to do if depth compare fails.
    StencilOp GetStencilZFail() const { return stencilZFail_; }
    /// Return stencil reference value.
    unsigned GetStencilRef() const { return stencilRef_; }
    /// Return stencil compare bitmask.
    unsigned GetStencilMask() const { return stencilMask_; }
    /// Return stream frequency by vertex buffer index.
    unsigned GetStreamFrequency(unsigned index) const;
    /// Return render target width and height.
    IntVector2 GetRenderTargetDimensions() const;
    /// Return force Shader Model 2 flag.
    bool GetForceSM2() const { return forceSM2_; }
    /// Return force fallback mode flag.
    bool GetForceFallback() const { return forceFallback_; }
    
    /// Add a GPU object to keep track of. Called by GPUObject.
    void AddGPUObject(GPUObject* object);
    /// Remove a GPU object. Called by GPUObject.
    void RemoveGPUObject(GPUObject* object);
    
    /// Return the API-specific alpha texture format.
    static unsigned GetAlphaFormat();
    /// Return the API-specific luminance texture format.
    static unsigned GetLuminanceFormat();
    /// Return the API-specific luminance alpha texture format.
    static unsigned GetLuminanceAlphaFormat();
    /// Return the API-specific RGB texture format.
    static unsigned GetRGBFormat();
    /// Return the API-specific RGBA texture format.
    static unsigned GetRGBAFormat();
    /// Return the API-specific depth texture format.
    static unsigned GetDepthFormat();
    /// Return the API-specific depth stencil texture format.
    static unsigned GetDepthStencilFormat();
    
private:
    /// Create the application window.
    bool OpenWindow(int width, int height);
    /// Adjust the window for new resolution and fullscreen mode.
    void AdjustWindow(int newWidth, int newHeight, bool newFullscreen);
    /// Create the Direct3D interface.
    bool CreateInterface();
    /// Create the Direct3D device.
    bool CreateDevice(unsigned adapter, unsigned deviceType);
    /// Check supported graphics features.
    void CheckFeatureSupport();
    /// Reset the Direct3D device.
    void ResetDevice();
    /// Notify all GPU resources so they can release themselves as needed.
    void OnDeviceLost();
    /// Notify all GPU resources so they can recreate themselves as needed.
    void OnDeviceReset();
    /// Reset cached rendering state.
    void ResetCachedState();
    /// Initialize texture unit mappings.
    void SetTextureUnitMappings();
    /// Handle operating system window message.
    void HandleWindowMessage(StringHash eventType, VariantMap& eventData);

    /// Implementation.
    GraphicsImpl* impl_;
    /// Window title.
    String windowTitle_;
    /// Window width.
    int width_;
    /// Window height.
    int height_;
    /// Multisampling mode.
    int multiSample_;
    /// Stored window X-position.
    int windowPosX_;
    /// Stored window Y-position.
    int windowPosY_;
    /// Fullscreen flag.
    bool fullscreen_;
    /// Vertical sync flag.
    bool vsync_;
    /// Triple buffering flag.
    bool tripleBuffer_;
    /// Flush GPU command queue flag.
    bool flushGPU_;
    /// Direct3D device lost flag.
    bool deviceLost_;
    /// System depth stencil flag.
    bool systemDepthStencil_;
    /// Hardware depth texture support flag.
    bool hardwareDepthSupport_;
    /// Hardware shadow map depth compare support flag.
    bool hardwareShadowSupport_;
    /// 24-bit shadow map support flag.
    bool hiresShadowSupport_;
    /// Stream offset support flag.
    bool streamOffsetSupport_;
    /// Fallback shader mode flag.
    bool fallback_;
    /// Shader Model 3 flag.
    bool hasSM3_;
    /// Force Shader Model 2 flag.
    bool forceSM2_;
    /// Force fallback shaders flag.
    bool forceFallback_;
    /// Query (used to flush the GPU command queue) issued flags.
    bool queryIssued_[NUM_QUERIES];
    /// Current query index
    unsigned queryIndex_;
    /// Number of primitives this frame.
    unsigned numPrimitives_;
    /// Number of batches this frame.
    unsigned numBatches_;
    /// GPU objects.
    Vector<GPUObject*> gpuObjects_;
    /// Vertex declarations.
    HashMap<unsigned long long, SharedPtr<VertexDeclaration> > vertexDeclarations_;
    /// Shadow map dummy color texture format.
    unsigned dummyColorFormat_;
    /// Shadow map depth texture format.
    unsigned shadowMapFormat_;
    /// Shadow map 24-bit depth texture format.
    unsigned hiresShadowMapFormat_;
    /// Vertex buffers in use.
    VertexBuffer* vertexBuffers_[MAX_VERTEX_STREAMS];
    /// Stream frequencies by vertex buffer.
    unsigned streamFrequencies_[MAX_VERTEX_STREAMS];
    /// Stream offsets by vertex buffer.
    unsigned streamOffsets_[MAX_VERTEX_STREAMS];
    /// Index buffer in use.
    IndexBuffer* indexBuffer_;
    /// Vertex declaration in use.
    VertexDeclaration* vertexDeclaration_;
    /// Vertex shader in use.
    ShaderVariation* vertexShader_;
    /// Pixel shader in use.
    ShaderVariation* pixelShader_;
    /// All known shader parameters.
    HashMap<StringHash, ShaderParameter> shaderParameters_;
    /// Initial assignment of vertex shader constant registers for testing overlap.
    StringHash vsRegisterAssignments_[MAX_CONSTANT_REGISTERS];
    /// Initial assignment of pixel shader constant registers for testing overlap.
    StringHash psRegisterAssignments_[MAX_CONSTANT_REGISTERS];
    /// Overlapping shader parameters flag. If false, overlap checks can be skipped.
    bool shaderParametersOverlap_;
    /// Textures in use.
    Texture* textures_[MAX_TEXTURE_UNITS];
    /// Texture unit mappings.
    HashMap<String, TextureUnit> textureUnits_;
    /// Render targets in use.
    RenderSurface* renderTargets_[MAX_RENDERTARGETS];
    /// Depth stencil buffer in use.
    RenderSurface* depthStencil_;
    /// Backbuffer depth stencil texture.
    SharedPtr<Texture2D> depthTexture_;
    /// Viewport coordinates.
    IntRect viewport_;
    /// Alpha test enable flag.
    bool alphaTest_;
    /// Alpha test compare mode.
    CompareMode alphaTestMode_;
    /// Alpha test reference value.
    float alphaRef_;
    /// Texture anisotropy level.
    unsigned textureAnisotropy_;
    /// Blending mode.
    BlendMode blendMode_;
    /// Color write enable.
    bool colorWrite_;
    /// Hardware culling mode.
    CullMode cullMode_;
    /// Depth constant bias.
    float constantDepthBias_;
    /// Depth slope scaled bias.
    float slopeScaledDepthBias_;
    /// Depth compare mode.
    CompareMode depthTestMode_;
    /// Depth write enable flag.
    bool depthWrite_;
    /// Polygon fill mode.
    FillMode fillMode_;
    /// Scissor test rectangle.
    IntRect scissorRect_;
    /// Scissor test enable flag.
    bool scissorTest_;
    /// Stencil test compare mode.
    CompareMode stencilTestMode_;
    /// Stencil operation on pass.
    StencilOp stencilPass_;
    /// Stencil operation on fail.
    StencilOp stencilFail_;
    /// Stencil operation on depth fail.
    StencilOp stencilZFail_;
    /// Stencil test enable flag.
    bool stencilTest_;
    /// Stencil test reference value.
    unsigned stencilRef_;
    /// Stencil compare bitmask.
    unsigned stencilMask_;
    /// Default texture filtering mode.
    TextureFilterMode defaultTextureFilterMode_;
};

/// Register Graphics library objects.
void RegisterGraphicsLibrary(Context* context);