/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#ifndef VECTOR_RENDERER_SPEC_H
#define VECTOR_RENDERER_SPEC_H

#include "graphics/VectorRenderer.h"

namespace Graphics {

/**
 * OpenVMS/__DECCXX PORT CHANGE - VectorRendererSpec IS NO LONGER A TEMPLATE.
 * ==========================================================================
 * Upstream this is `template<typename PixelType> class VectorRendererSpec`,
 * instantiated for uint16 and uint32.  Here PixelType is a plain `typedef uint16`.
 *
 * THIS WAS NOT THE FIX FOR THIS FILE'S COMPILER CRASH, and it is NOT load-bearing.
 * That crash was caused by the /NOOPTIMIZE flag VectorRendererSpec.cpp was built with;
 * it compiles at plain /OPTIMIZE=(LEVEL=3,TUNE=HOST) with no source change at all.
 * Full account in the port note at the top of VectorRendererSpec.cpp and in DESCRIP.MMS.
 * The de-templating was round 5 of 7 wrong guesses and it left the traceback
 * bit-identical - which, in hindsight, was the loudest possible signal that the cause
 * lay outside this file, since you cannot rewrite every routine in a module and get a
 * byte-for-byte identical codegen failure.
 *
 * IT IS KEPT because it is harmless and mildly beneficial: it removes dead uint32
 * paths and a smaller module is easier to bisect on a fragile compiler.  REVERTING IT
 * IS SAFE if it ever gets in the way.
 *
 * It is sound for two grep-verified reasons:
 *  1. PixelType is ALWAYS uint16 here.  SurfaceSDL creates _overlayscreen with a
 *     hard-coded literal 16 bpp (backends/graphics/surfacesdl/surfacesdl-graphics.cpp
 *     :851) and _overlayFormat.bytesPerPixel is assigned from that surface and nowhere
 *     else (:860), so getOverlayFormat().bytesPerPixel is always 2 and the
 *     `bytesPerPixel == 4` branches were dead.  A compile-time assert in the .cpp pins
 *     the invariant, so a future 32bpp overlay breaks the BUILD rather than silently
 *     rendering at the wrong depth.
 *  2. NO ODR RISK: this header is included by exactly ONE translation unit in the whole
 *     tree - VectorRendererSpec.cpp itself.  createRenderer(), the only factory, lives
 *     in that same file and returns a VectorRenderer* base pointer, so no other TU can
 *     see or name these types.  That single-includer fact is what makes a
 *     namespace-scope typedef legitimate; check it before reusing this trick.
 *
 * TO RESTORE THE TEMPLATE (e.g. porting to a backend with a 32bpp overlay): make
 * PixelType a template parameter on both classes again, restore
 * `template<typename PixelType>` before each method definition in the .cpp, and re-add
 * the bytesPerPixel == 4 branches in createRenderer().
 *
 * ---- upstream documentation follows ----
 *
 * VectorRendererSpec: Specialized Vector Renderer Class
 *
 * This implements the basic subset of vector operations for all platforms
 * by allowing the user to provide the actual Pixel Type and pixel
 * information structs.
 *
 * @param PixelType Defines a type which may hold the color value of a single
 *        pixel, such as "byte" or "uint16" for 8 and 16 BPP respectively.
 *
 * TODO: Expand documentation.
 *
 * @see VectorRenderer
 */
typedef uint16 PixelType;

class VectorRendererSpec : public VectorRenderer {
	typedef VectorRenderer Base;

public:
	VectorRendererSpec(PixelFormat format);

	void drawLine(int x1, int y1, int x2, int y2);
	void drawCircle(int x, int y, int r);
	void drawSquare(int x, int y, int w, int h);
	void drawRoundedSquare(int x, int y, int r, int w, int h);
	void drawTriangle(int x, int y, int base, int height, TriangleOrientation orient);
	void drawTab(int x, int y, int r, int w, int h);
	void drawBeveledSquare(int x, int y, int w, int h, int bevel) {
		drawBevelSquareAlg(x, y, w, h, bevel, _bevelColor, _fgColor, Base::_fillMode != kFillDisabled);
	}
	// OpenVMS/__DECCXX: the `= Common::Rect(0, 0, 0, 0)` default argument was REMOVED
	// as DEAD CODE - VectorRenderer::drawString (VectorRenderer.h:476) is pure virtual
	// and declares no default, and the only caller in the tree (gui/ThemeEngine.cpp:251)
	// always passes all eight arguments explicitly.  (It was originally removed on the
	// theory that its temporary caused this file's compiler assertion; that theory was
	// wrong - see the port note at the top of VectorRendererSpec.cpp - but the removal
	// stands on its own merits.)
	void drawString(const Graphics::Font *font, const Common::String &text,
					const Common::Rect &area, Graphics::TextAlign alignH,
					GUI::ThemeEngine::TextAlignVertical alignV, int deltax, bool elipsis, const Common::Rect &textDrawableArea);

	void setFgColor(uint8 r, uint8 g, uint8 b) { _fgColor = _format.RGBToColor(r, g, b); }
	void setBgColor(uint8 r, uint8 g, uint8 b) { _bgColor = _format.RGBToColor(r, g, b); }
	void setBevelColor(uint8 r, uint8 g, uint8 b) { _bevelColor = _format.RGBToColor(r, g, b); }
	void setGradientColors(uint8 r1, uint8 g1, uint8 b1, uint8 r2, uint8 g2, uint8 b2);

	void copyFrame(OSystem *sys, const Common::Rect &r);
	// OpenVMS/__DECCXX: the bounds Rect is a NAMED local rather than a temporary bound
	// to copyFrame's const& parameter.  Cosmetic only - this was part of a wrong theory
	// about this file's compiler assertion (see the port note at the top of
	// VectorRendererSpec.cpp); harmless, so left as-is.
	void copyWholeFrame(OSystem *sys) {
		Common::Rect wholeFrame(0, 0, _activeSurface->w, _activeSurface->h);
		copyFrame(sys, wholeFrame);
	}

	void fillSurface();
	void blitSurface(const Graphics::Surface *source, const Common::Rect &r);
	void blitSubSurface(const Graphics::Surface *source, const Common::Rect &r);
	void blitAlphaBitmap(const Graphics::Surface *source, const Common::Rect &r);

	void applyScreenShading(GUI::ThemeEngine::ShadingStyle shadingStyle);

protected:

	/**
	 * Draws a single pixel on the surface with the given coordinates and
	 * the given color.
	 *
	 * @param x Horizontal coordinate of the pixel.
	 * @param y Vertical coordinate of the pixel.
	 * @param color Color of the pixel
	 */
	inline void putPixel(int x, int y, PixelType color) {
		PixelType *ptr = (PixelType *)_activeSurface->getBasePtr(x, y);
		*ptr = color;
	}

	/**
	 * Blends a single pixel on the surface with the given coordinates, color
	 * and Alpha intensity.
	 *
	 * @param x Horizontal coordinate of the pixel.
	 * @param y Vertical coordinate of the pixel.
	 * @param color Color of the pixel
	 * @param alpha Alpha intensity of the pixel (0-255)
	 */
	inline void blendPixel(int x, int y, PixelType color, uint8 alpha) {
		blendPixelPtr((PixelType *)Base::_activeSurface->getBasePtr(x, y), color, alpha);
	}

	/**
	 * Blends a single pixel on the surface in the given pixel pointer, using supplied color
	 * and Alpha intensity.
	 *
	 * This is implemented to prevent blendPixel() to calculate the surface pointer on each call.
	 * Optimized drawing algorithms should call this function when possible.
	 *
	 * @see blendPixel
	 * @param ptr Pointer to the pixel to blend on top of
	 * @param color Color of the pixel
	 * @param alpha Alpha intensity of the pixel (0-255)
	 */
	inline void blendPixelPtr(PixelType *ptr, PixelType color, uint8 alpha);

	/**
	 * Blends a single pixel on the surface in the given pixel pointer, using supplied color
	 * and Alpha intensity.
	 * If the destination pixel has 0 alpha, set the color and alpha channels,
	 * overwriting the destination pixel entirely.
	 * If the destination pixel has non-zero alpha, blend dest with src.
	 *
	 * This is implemented to prevent blendPixel() to calculate the surface pointer on each call.
	 * Optimized drawing algorithms should call this function when possible.
	 *
	 * @see blendPixel
	 * @param ptr Pointer to the pixel to blend on top of
	 * @param color Color of the pixel
	 * @param alpha Alpha intensity of the pixel (0-255)
	 */
	inline void blendPixelDestAlphaPtr(PixelType *ptr, PixelType color, uint8 alpha);


	/**
	 * PRIMITIVE DRAWING ALGORITHMS
	 *
	 * Generic algorithms for drawing all kinds of aliased primitive shapes.
	 * These may be overloaded in inheriting classes to implement platform-specific
	 * optimizations or improve looks.
	 *
	 * @see VectorRendererAA
	 * @see VectorRendererAA::drawLineAlg
	 * @see VectorRendererAA::drawCircleAlg
	 */
	virtual void drawLineAlg(int x1, int y1, int x2, int y2,
	    int dx, int dy, PixelType color);

	virtual void drawCircleAlg(int x, int y, int r,
	    PixelType color, FillMode fill_m);

	virtual void drawRoundedSquareAlg(int x1, int y1, int r, int w, int h,
	    PixelType color, FillMode fill_m);

	virtual void drawBorderRoundedSquareAlg(int x1, int y1, int r, int w, int h,
	    PixelType color, FillMode fill_m, uint8 alpha_t, uint8 alpha_r, uint8 alpha_b, uint8 alpha_l);

	virtual void drawInteriorRoundedSquareAlg(int x1, int y1, int r, int w, int h,
	    PixelType color, FillMode fill_m);

	virtual void drawSquareAlg(int x, int y, int w, int h,
	    PixelType color, FillMode fill_m);

	virtual void drawTriangleVertAlg(int x, int y, int w, int h,
	    bool inverted, PixelType color, FillMode fill_m);

	virtual void drawTriangleFast(int x, int y, int size,
	    bool inverted, PixelType color, FillMode fill_m);

	virtual void drawBevelSquareAlg(int x, int y, int w, int h,
	    int bevel, PixelType top_color, PixelType bottom_color, bool fill);

	virtual void drawTabAlg(int x, int y, int w, int h, int r,
	    PixelType color, VectorRenderer::FillMode fill_m,
	    int baseLeft = 0, int baseRight = 0);

	virtual void drawTabShadow(int x, int y, int w, int h, int r);

	virtual void drawBevelTabAlg(int x, int y, int w, int h,
	    int bevel, PixelType topColor, PixelType bottomColor,
	    int baseLeft = 0, int baseRight = 0);

	/**
	 * SHADOW DRAWING ALGORITHMS
	 *
	 * Optimized versions of the primitive drawing algorithms with alpha blending
	 * for shadow drawing.
	 * There functions may be overloaded in inheriting classes to improve performance
	 * in the slowest platforms where pixel alpha blending just doesn't cut it.
	 *
	 * @param offset Intensity/size of the shadow.
	 */
	virtual void drawSquareShadow(int x, int y, int w, int h, int offset);
	virtual void drawRoundedSquareShadow(int x, int y, int r, int w, int h, int offset);

	/**
	 * Calculates the color gradient on a given point.
	 * This function assumes that the gradient start/end colors have been set
	 * beforehand from the API function call.
	 *
	 * @param pos Progress of the gradient.
	 * @param max Maximum amount of the progress.
	 * @return Composite color of the gradient at the given "progress" amount.
	 */
	inline PixelType calcGradient(uint32 pos, uint32 max);

	void precalcGradient(int h);
	void gradientFill(PixelType *first, int width, int x, int y);

	/**
	 * Fills several pixels in a row with a given color and the specified alpha blending.
	 *
	 * @see blendPixelPtr
	 * @see blendPixel
	 * @param first Pointer to the first pixel to fill.
	 * @param last Pointer to the last pixel to fill.
	 * @param color Color of the pixel
	 * @param alpha Alpha intensity of the pixel (0-255)
	 */
	inline void blendFill(PixelType *first, PixelType *last, PixelType color, uint8 alpha) {
		while (first != last) blendPixelPtr(first++, color, alpha);
	}

	void darkenFill(PixelType *first, PixelType *last);

	const PixelFormat _format;
	const PixelType _redMask, _greenMask, _blueMask, _alphaMask;

	PixelType _fgColor; /**< Foreground color currently being used to draw on the renderer */
	PixelType _bgColor; /**< Background color currently being used to draw on the renderer */

	PixelType _gradientStart; /**< Start color for the fill gradient */
	PixelType _gradientEnd; /**< End color for the fill gradient */

	int _gradientBytes[3]; /**< Color bytes of the active gradient, used to speed up calculation */

	Common::Array<PixelType> _gradCache;
	Common::Array<int> _gradIndexes;

	PixelType _bevelColor;
	PixelType _bitmapAlphaColor;
};


#ifndef DISABLE_FANCY_THEMES
/**
 * VectorRendererAA: Anti-Aliased Vector Renderer Class
 *
 * This class inherits all the functionality of the VectorRendererSpec
 * class but uses better looking yet slightly slower AA algorithms for drawing
 * most primitives. May be used in faster platforms.
 *
 * NOTE (OpenVMS port): de-templated along with VectorRendererSpec - see the long
 * note on that class above.  This class IS COMPILED AND USED in this port:
 * DISABLE_FANCY_THEMES is left undefined, as upstream.  (It was once believed that
 * defining it crashed the compiler on VectorRendererSpec.cpp; the real cause was that
 * file's /NOOPTIMIZE build flag - see config.h.)
 *
 * TODO: Expand documentation.
 *
 * @see VectorRenderer
 * @see VectorRendererSpec
 */
class VectorRendererAA : public VectorRendererSpec {
	typedef VectorRendererSpec Base;
public:
	VectorRendererAA(PixelFormat format) : VectorRendererSpec(format) {
	}

protected:
	/**
	 * "Wu's Line Antialiasing Algorithm" as published by Xiaolin Wu, July 1991
	 * Based on the implementation found in Michael Abrash's Graphics Programming Black Book.
	 *
	 * Generic line drawing algorithm for the Antialiased renderer. Optimized with no
	 * floating point operations, assumes no special cases.
	 *
	 * @see VectorRenderer::drawLineAlg()
	 */
	virtual void drawLineAlg(int x1, int y1, int x2, int y2, int dx, int dy, PixelType color);

	/**
	 * "Wu's Circle Antialiasing Algorithm" as published by Xiaolin Wu, July 1991
	 * Based on the theoretical concept of the algorithm.
	 *
	 * Implementation of Wu's algorithm for circles using fixed point arithmetics.
	 * Could be quite fast.
	 *
	 * @see VectorRenderer::drawCircleAlg()
	 */
	virtual void drawCircleAlg(int x, int y, int r, PixelType color, VectorRenderer::FillMode fill_m);

	/**
	 * "Wu's Circle Antialiasing Algorithm" as published by Xiaolin Wu, July 1991,
	 * modified with corner displacement to allow drawing of squares with rounded
	 * corners.
	 *
	 * @see VectorRenderer::drawRoundedAlg()
	 */
	virtual void drawRoundedSquareAlg(int x1, int y1, int r, int w, int h, PixelType color, VectorRenderer::FillMode fill_m);

	virtual void drawBorderRoundedSquareAlg(int x1, int y1, int r, int w, int h, PixelType color, VectorRenderer::FillMode fill_m, uint8 alpha_t, uint8 alpha_l, uint8 alpha_r, uint8 alpha_b);

	virtual void drawInteriorRoundedSquareAlg(int x1, int y1, int r, int w, int h, PixelType color, VectorRenderer::FillMode fill_m);

	virtual void drawRoundedSquareShadow(int x, int y, int r, int w, int h, int offset) {
		Base::drawRoundedSquareShadow(x, y, r, w, h, offset);
	}

	virtual void drawTabAlg(int x, int y, int w, int h, int r,
	    PixelType color, VectorRenderer::FillMode fill_m,
	    int baseLeft = 0, int baseRight = 0);
};
#endif

}
#endif
