lnvis

nanovg.h (28018B)

---

 //
 // Copyright (c) 2013 Mikko Mononen memon@inside.org
 //
 // This software is provided 'as-is', without any express or implied
 // warranty.  In no event will the authors be held liable for any damages
 // arising from the use of this software.
 // Permission is granted to anyone to use this software for any purpose,
 // including commercial applications, and to alter it and redistribute it
 // freely, subject to the following restrictions:
 // 1. The origin of this software must not be misrepresented; you must not
 //    claim that you wrote the original software. If you use this software
 //    in a product, an acknowledgment in the product documentation would be
 //    appreciated but is not required.
 // 2. Altered source versions must be plainly marked as such, and must not be
 //    misrepresented as being the original software.
 // 3. This notice may not be removed or altered from any source distribution.
 //
 
 #ifndef NANOVG_H
 #define NANOVG_H
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 #define NVG_PI 3.14159265358979323846264338327f
 
 #ifdef _MSC_VER
 #pragma warning(push)
 #pragma warning(disable: 4201)  // nonstandard extension used : nameless struct/union
 #endif
 
 typedef struct NVGcontext NVGcontext;
 
 struct NVGcolor {
 	union {
 		float rgba[4];
 		struct {
 			float r,g,b,a;
 		};
 	};
 };
 typedef struct NVGcolor NVGcolor;
 
 struct NVGpaint {
 	float xform[6];
 	float extent[2];
 	float radius;
 	float feather;
 	NVGcolor innerColor;
 	NVGcolor outerColor;
 	int image;
 };
 typedef struct NVGpaint NVGpaint;
 
 enum NVGwinding {
 	NVG_CCW = 1,			// Winding for solid shapes
 	NVG_CW = 2,				// Winding for holes
 };
 
 enum NVGsolidity {
 	NVG_SOLID = 1,			// CCW
 	NVG_HOLE = 2,			// CW
 };
 
 enum NVGlineCap {
 	NVG_BUTT,
 	NVG_ROUND,
 	NVG_SQUARE,
 	NVG_BEVEL,
 	NVG_MITER,
 };
 
 enum NVGalign {
 	// Horizontal align
 	NVG_ALIGN_LEFT 		= 1<<0,	// Default, align text horizontally to left.
 	NVG_ALIGN_CENTER 	= 1<<1,	// Align text horizontally to center.
 	NVG_ALIGN_RIGHT 	= 1<<2,	// Align text horizontally to right.
 	// Vertical align
 	NVG_ALIGN_TOP 		= 1<<3,	// Align text vertically to top.
 	NVG_ALIGN_MIDDLE	= 1<<4,	// Align text vertically to middle.
 	NVG_ALIGN_BOTTOM	= 1<<5,	// Align text vertically to bottom.
 	NVG_ALIGN_BASELINE	= 1<<6, // Default, align text vertically to baseline.
 };
 
 enum NVGblendFactor {
 	NVG_ZERO = 1<<0,
 	NVG_ONE = 1<<1,
 	NVG_SRC_COLOR = 1<<2,
 	NVG_ONE_MINUS_SRC_COLOR = 1<<3,
 	NVG_DST_COLOR = 1<<4,
 	NVG_ONE_MINUS_DST_COLOR = 1<<5,
 	NVG_SRC_ALPHA = 1<<6,
 	NVG_ONE_MINUS_SRC_ALPHA = 1<<7,
 	NVG_DST_ALPHA = 1<<8,
 	NVG_ONE_MINUS_DST_ALPHA = 1<<9,
 	NVG_SRC_ALPHA_SATURATE = 1<<10,
 };
 
 enum NVGcompositeOperation {
 	NVG_SOURCE_OVER,
 	NVG_SOURCE_IN,
 	NVG_SOURCE_OUT,
 	NVG_ATOP,
 	NVG_DESTINATION_OVER,
 	NVG_DESTINATION_IN,
 	NVG_DESTINATION_OUT,
 	NVG_DESTINATION_ATOP,
 	NVG_LIGHTER,
 	NVG_COPY,
 	NVG_XOR,
 };
 
 struct NVGcompositeOperationState {
 	int srcRGB;
 	int dstRGB;
 	int srcAlpha;
 	int dstAlpha;
 };
 typedef struct NVGcompositeOperationState NVGcompositeOperationState;
 
 struct NVGglyphPosition {
 	const char* str;	// Position of the glyph in the input string.
 	float x;			// The x-coordinate of the logical glyph position.
 	float minx, maxx;	// The bounds of the glyph shape.
 };
 typedef struct NVGglyphPosition NVGglyphPosition;
 
 struct NVGtextRow {
 	const char* start;	// Pointer to the input text where the row starts.
 	const char* end;	// Pointer to the input text where the row ends (one past the last character).
 	const char* next;	// Pointer to the beginning of the next row.
 	float width;		// Logical width of the row.
 	float minx, maxx;	// Actual bounds of the row. Logical with and bounds can differ because of kerning and some parts over extending.
 };
 typedef struct NVGtextRow NVGtextRow;
 
 enum NVGimageFlags {
     NVG_IMAGE_GENERATE_MIPMAPS	= 1<<0,     // Generate mipmaps during creation of the image.
 	NVG_IMAGE_REPEATX			= 1<<1,		// Repeat image in X direction.
 	NVG_IMAGE_REPEATY			= 1<<2,		// Repeat image in Y direction.
 	NVG_IMAGE_FLIPY				= 1<<3,		// Flips (inverses) image in Y direction when rendered.
 	NVG_IMAGE_PREMULTIPLIED		= 1<<4,		// Image data has premultiplied alpha.
 	NVG_IMAGE_NEAREST			= 1<<5,		// Image interpolation is Nearest instead Linear
 };
 
 // Begin drawing a new frame
 // Calls to nanovg drawing API should be wrapped in nvgBeginFrame() & nvgEndFrame()
 // nvgBeginFrame() defines the size of the window to render to in relation currently
 // set viewport (i.e. glViewport on GL backends). Device pixel ration allows to
 // control the rendering on Hi-DPI devices.
 // For example, GLFW returns two dimension for an opened window: window size and
 // frame buffer size. In that case you would set windowWidth/Height to the window size
 // devicePixelRatio to: frameBufferWidth / windowWidth.
 void nvgBeginFrame(NVGcontext* ctx, float windowWidth, float windowHeight, float devicePixelRatio);
 
 // Cancels drawing the current frame.
 void nvgCancelFrame(NVGcontext* ctx);
 
 // Ends drawing flushing remaining render state.
 void nvgEndFrame(NVGcontext* ctx);
 
 //
 // Composite operation
 //
 // The composite operations in NanoVG are modeled after HTML Canvas API, and
 // the blend func is based on OpenGL (see corresponding manuals for more info).
 // The colors in the blending state have premultiplied alpha.
 
 // Sets the composite operation. The op parameter should be one of NVGcompositeOperation.
 void nvgGlobalCompositeOperation(NVGcontext* ctx, int op);
 
 // Sets the composite operation with custom pixel arithmetic. The parameters should be one of NVGblendFactor.
 void nvgGlobalCompositeBlendFunc(NVGcontext* ctx, int sfactor, int dfactor);
 
 // Sets the composite operation with custom pixel arithmetic for RGB and alpha components separately. The parameters should be one of NVGblendFactor.
 void nvgGlobalCompositeBlendFuncSeparate(NVGcontext* ctx, int srcRGB, int dstRGB, int srcAlpha, int dstAlpha);
 
 //
 // Color utils
 //
 // Colors in NanoVG are stored as unsigned ints in ABGR format.
 
 // Returns a color value from red, green, blue values. Alpha will be set to 255 (1.0f).
 NVGcolor nvgRGB(unsigned char r, unsigned char g, unsigned char b);
 
 // Returns a color value from red, green, blue values. Alpha will be set to 1.0f.
 NVGcolor nvgRGBf(float r, float g, float b);
 
 
 // Returns a color value from red, green, blue and alpha values.
 NVGcolor nvgRGBA(unsigned char r, unsigned char g, unsigned char b, unsigned char a);
 
 // Returns a color value from red, green, blue and alpha values.
 NVGcolor nvgRGBAf(float r, float g, float b, float a);
 
 
 // Linearly interpolates from color c0 to c1, and returns resulting color value.
 NVGcolor nvgLerpRGBA(NVGcolor c0, NVGcolor c1, float u);
 
 // Sets transparency of a color value.
 NVGcolor nvgTransRGBA(NVGcolor c0, unsigned char a);
 
 // Sets transparency of a color value.
 NVGcolor nvgTransRGBAf(NVGcolor c0, float a);
 
 // Returns color value specified by hue, saturation and lightness.
 // HSL values are all in range [0..1], alpha will be set to 255.
 NVGcolor nvgHSL(float h, float s, float l);
 
 // Returns color value specified by hue, saturation and lightness and alpha.
 // HSL values are all in range [0..1], alpha in range [0..255]
 NVGcolor nvgHSLA(float h, float s, float l, unsigned char a);
 
 //
 // State Handling
 //
 // NanoVG contains state which represents how paths will be rendered.
 // The state contains transform, fill and stroke styles, text and font styles,
 // and scissor clipping.
 
 // Pushes and saves the current render state into a state stack.
 // A matching nvgRestore() must be used to restore the state.
 void nvgSave(NVGcontext* ctx);
 
 // Pops and restores current render state.
 void nvgRestore(NVGcontext* ctx);
 
 // Resets current render state to default values. Does not affect the render state stack.
 void nvgReset(NVGcontext* ctx);
 
 //
 // Render styles
 //
 // Fill and stroke render style can be either a solid color or a paint which is a gradient or a pattern.
 // Solid color is simply defined as a color value, different kinds of paints can be created
 // using nvgLinearGradient(), nvgBoxGradient(), nvgRadialGradient() and nvgImagePattern().
 //
 // Current render style can be saved and restored using nvgSave() and nvgRestore().
 
 // Sets whether to draw antialias for nvgStroke() and nvgFill(). It's enabled by default.
 void nvgShapeAntiAlias(NVGcontext* ctx, int enabled);
 
 // Sets current stroke style to a solid color.
 void nvgStrokeColor(NVGcontext* ctx, NVGcolor color);
 
 // Sets current stroke style to a paint, which can be a one of the gradients or a pattern.
 void nvgStrokePaint(NVGcontext* ctx, NVGpaint paint);
 
 // Sets current fill style to a solid color.
 void nvgFillColor(NVGcontext* ctx, NVGcolor color);
 
 // Sets current fill style to a paint, which can be a one of the gradients or a pattern.
 void nvgFillPaint(NVGcontext* ctx, NVGpaint paint);
 
 // Sets the miter limit of the stroke style.
 // Miter limit controls when a sharp corner is beveled.
 void nvgMiterLimit(NVGcontext* ctx, float limit);
 
 // Sets the stroke width of the stroke style.
 void nvgStrokeWidth(NVGcontext* ctx, float size);
 
 // Sets how the end of the line (cap) is drawn,
 // Can be one of: NVG_BUTT (default), NVG_ROUND, NVG_SQUARE.
 void nvgLineCap(NVGcontext* ctx, int cap);
 
 // Sets how sharp path corners are drawn.
 // Can be one of NVG_MITER (default), NVG_ROUND, NVG_BEVEL.
 void nvgLineJoin(NVGcontext* ctx, int join);
 
 // Sets the transparency applied to all rendered shapes.
 // Already transparent paths will get proportionally more transparent as well.
 void nvgGlobalAlpha(NVGcontext* ctx, float alpha);
 
 //
 // Transforms
 //
 // The paths, gradients, patterns and scissor region are transformed by an transformation
 // matrix at the time when they are passed to the API.
 // The current transformation matrix is a affine matrix:
 //   [sx kx tx]
 //   [ky sy ty]
 //   [ 0  0  1]
 // Where: sx,sy define scaling, kx,ky skewing, and tx,ty translation.
 // The last row is assumed to be 0,0,1 and is not stored.
 //
 // Apart from nvgResetTransform(), each transformation function first creates
 // specific transformation matrix and pre-multiplies the current transformation by it.
 //
 // Current coordinate system (transformation) can be saved and restored using nvgSave() and nvgRestore().
 
 // Resets current transform to a identity matrix.
 void nvgResetTransform(NVGcontext* ctx);
 
 // Premultiplies current coordinate system by specified matrix.
 // The parameters are interpreted as matrix as follows:
 //   [a c e]
 //   [b d f]
 //   [0 0 1]
 void nvgTransform(NVGcontext* ctx, float a, float b, float c, float d, float e, float f);
 
 // Translates current coordinate system.
 void nvgTranslate(NVGcontext* ctx, float x, float y);
 
 // Rotates current coordinate system. Angle is specified in radians.
 void nvgRotate(NVGcontext* ctx, float angle);
 
 // Skews the current coordinate system along X axis. Angle is specified in radians.
 void nvgSkewX(NVGcontext* ctx, float angle);
 
 // Skews the current coordinate system along Y axis. Angle is specified in radians.
 void nvgSkewY(NVGcontext* ctx, float angle);
 
 // Scales the current coordinate system.
 void nvgScale(NVGcontext* ctx, float x, float y);
 
 // Stores the top part (a-f) of the current transformation matrix in to the specified buffer.
 //   [a c e]
 //   [b d f]
 //   [0 0 1]
 // There should be space for 6 floats in the return buffer for the values a-f.
 void nvgCurrentTransform(NVGcontext* ctx, float* xform);
 
 
 // The following functions can be used to make calculations on 2x3 transformation matrices.
 // A 2x3 matrix is represented as float[6].
 
 // Sets the transform to identity matrix.
 void nvgTransformIdentity(float* dst);
 
 // Sets the transform to translation matrix matrix.
 void nvgTransformTranslate(float* dst, float tx, float ty);
 
 // Sets the transform to scale matrix.
 void nvgTransformScale(float* dst, float sx, float sy);
 
 // Sets the transform to rotate matrix. Angle is specified in radians.
 void nvgTransformRotate(float* dst, float a);
 
 // Sets the transform to skew-x matrix. Angle is specified in radians.
 void nvgTransformSkewX(float* dst, float a);
 
 // Sets the transform to skew-y matrix. Angle is specified in radians.
 void nvgTransformSkewY(float* dst, float a);
 
 // Sets the transform to the result of multiplication of two transforms, of A = A*B.
 void nvgTransformMultiply(float* dst, const float* src);
 
 // Sets the transform to the result of multiplication of two transforms, of A = B*A.
 void nvgTransformPremultiply(float* dst, const float* src);
 
 // Sets the destination to inverse of specified transform.
 // Returns 1 if the inverse could be calculated, else 0.
 int nvgTransformInverse(float* dst, const float* src);
 
 // Transform a point by given transform.
 void nvgTransformPoint(float* dstx, float* dsty, const float* xform, float srcx, float srcy);
 
 // Converts degrees to radians and vice versa.
 float nvgDegToRad(float deg);
 float nvgRadToDeg(float rad);
 
 //
 // Images
 //
 // NanoVG allows you to load jpg, png, psd, tga, pic and gif files to be used for rendering.
 // In addition you can upload your own image. The image loading is provided by stb_image.
 // The parameter imageFlags is combination of flags defined in NVGimageFlags.
 
 // Creates image by loading it from the disk from specified file name.
 // Returns handle to the image.
 int nvgCreateImage(NVGcontext* ctx, const char* filename, int imageFlags);
 
 // Creates image by loading it from the specified chunk of memory.
 // Returns handle to the image.
 int nvgCreateImageMem(NVGcontext* ctx, int imageFlags, unsigned char* data, int ndata);
 
 // Creates image from specified image data.
 // Returns handle to the image.
 int nvgCreateImageRGBA(NVGcontext* ctx, int w, int h, int imageFlags, const unsigned char* data);
 
 // Updates image data specified by image handle.
 void nvgUpdateImage(NVGcontext* ctx, int image, const unsigned char* data);
 
 // Returns the dimensions of a created image.
 void nvgImageSize(NVGcontext* ctx, int image, int* w, int* h);
 
 // Deletes created image.
 void nvgDeleteImage(NVGcontext* ctx, int image);
 
 //
 // Paints
 //
 // NanoVG supports four types of paints: linear gradient, box gradient, radial gradient and image pattern.
 // These can be used as paints for strokes and fills.
 
 // Creates and returns a linear gradient. Parameters (sx,sy)-(ex,ey) specify the start and end coordinates
 // of the linear gradient, icol specifies the start color and ocol the end color.
 // The gradient is transformed by the current transform when it is passed to nvgFillPaint() or nvgStrokePaint().
 NVGpaint nvgLinearGradient(NVGcontext* ctx, float sx, float sy, float ex, float ey,
 						   NVGcolor icol, NVGcolor ocol);
 
 // Creates and returns a box gradient. Box gradient is a feathered rounded rectangle, it is useful for rendering
 // drop shadows or highlights for boxes. Parameters (x,y) define the top-left corner of the rectangle,
 // (w,h) define the size of the rectangle, r defines the corner radius, and f feather. Feather defines how blurry
 // the border of the rectangle is. Parameter icol specifies the inner color and ocol the outer color of the gradient.
 // The gradient is transformed by the current transform when it is passed to nvgFillPaint() or nvgStrokePaint().
 NVGpaint nvgBoxGradient(NVGcontext* ctx, float x, float y, float w, float h,
 						float r, float f, NVGcolor icol, NVGcolor ocol);
 
 // Creates and returns a radial gradient. Parameters (cx,cy) specify the center, inr and outr specify
 // the inner and outer radius of the gradient, icol specifies the start color and ocol the end color.
 // The gradient is transformed by the current transform when it is passed to nvgFillPaint() or nvgStrokePaint().
 NVGpaint nvgRadialGradient(NVGcontext* ctx, float cx, float cy, float inr, float outr,
 						   NVGcolor icol, NVGcolor ocol);
 
 // Creates and returns an image patter. Parameters (ox,oy) specify the left-top location of the image pattern,
 // (ex,ey) the size of one image, angle rotation around the top-left corner, image is handle to the image to render.
 // The gradient is transformed by the current transform when it is passed to nvgFillPaint() or nvgStrokePaint().
 NVGpaint nvgImagePattern(NVGcontext* ctx, float ox, float oy, float ex, float ey,
 						 float angle, int image, float alpha);
 
 //
 // Scissoring
 //
 // Scissoring allows you to clip the rendering into a rectangle. This is useful for various
 // user interface cases like rendering a text edit or a timeline.
 
 // Sets the current scissor rectangle.
 // The scissor rectangle is transformed by the current transform.
 void nvgScissor(NVGcontext* ctx, float x, float y, float w, float h);
 
 // Intersects current scissor rectangle with the specified rectangle.
 // The scissor rectangle is transformed by the current transform.
 // Note: in case the rotation of previous scissor rect differs from
 // the current one, the intersection will be done between the specified
 // rectangle and the previous scissor rectangle transformed in the current
 // transform space. The resulting shape is always rectangle.
 void nvgIntersectScissor(NVGcontext* ctx, float x, float y, float w, float h);
 
 // Reset and disables scissoring.
 void nvgResetScissor(NVGcontext* ctx);
 
 //
 // Paths
 //
 // Drawing a new shape starts with nvgBeginPath(), it clears all the currently defined paths.
 // Then you define one or more paths and sub-paths which describe the shape. The are functions
 // to draw common shapes like rectangles and circles, and lower level step-by-step functions,
 // which allow to define a path curve by curve.
 //
 // NanoVG uses even-odd fill rule to draw the shapes. Solid shapes should have counter clockwise
 // winding and holes should have counter clockwise order. To specify winding of a path you can
 // call nvgPathWinding(). This is useful especially for the common shapes, which are drawn CCW.
 //
 // Finally you can fill the path using current fill style by calling nvgFill(), and stroke it
 // with current stroke style by calling nvgStroke().
 //
 // The curve segments and sub-paths are transformed by the current transform.
 
 // Clears the current path and sub-paths.
 void nvgBeginPath(NVGcontext* ctx);
 
 // Starts new sub-path with specified point as first point.
 void nvgMoveTo(NVGcontext* ctx, float x, float y);
 
 // Adds line segment from the last point in the path to the specified point.
 void nvgLineTo(NVGcontext* ctx, float x, float y);
 
 // Adds cubic bezier segment from last point in the path via two control points to the specified point.
 void nvgBezierTo(NVGcontext* ctx, float c1x, float c1y, float c2x, float c2y, float x, float y);
 
 // Adds quadratic bezier segment from last point in the path via a control point to the specified point.
 void nvgQuadTo(NVGcontext* ctx, float cx, float cy, float x, float y);
 
 // Adds an arc segment at the corner defined by the last path point, and two specified points.
 void nvgArcTo(NVGcontext* ctx, float x1, float y1, float x2, float y2, float radius);
 
 // Closes current sub-path with a line segment.
 void nvgClosePath(NVGcontext* ctx);
 
 // Sets the current sub-path winding, see NVGwinding and NVGsolidity.
 void nvgPathWinding(NVGcontext* ctx, int dir);
 
 // Creates new circle arc shaped sub-path. The arc center is at cx,cy, the arc radius is r,
 // and the arc is drawn from angle a0 to a1, and swept in direction dir (NVG_CCW, or NVG_CW).
 // Angles are specified in radians.
 void nvgArc(NVGcontext* ctx, float cx, float cy, float r, float a0, float a1, int dir);
 
 // Creates new rectangle shaped sub-path.
 void nvgRect(NVGcontext* ctx, float x, float y, float w, float h);
 
 // Creates new rounded rectangle shaped sub-path.
 void nvgRoundedRect(NVGcontext* ctx, float x, float y, float w, float h, float r);
 
 // Creates new rounded rectangle shaped sub-path with varying radii for each corner.
 void nvgRoundedRectVarying(NVGcontext* ctx, float x, float y, float w, float h, float radTopLeft, float radTopRight, float radBottomRight, float radBottomLeft);
 
 // Creates new ellipse shaped sub-path.
 void nvgEllipse(NVGcontext* ctx, float cx, float cy, float rx, float ry);
 
 // Creates new circle shaped sub-path.
 void nvgCircle(NVGcontext* ctx, float cx, float cy, float r);
 
 // Fills the current path with current fill style.
 void nvgFill(NVGcontext* ctx);
 
 // Fills the current path with current stroke style.
 void nvgStroke(NVGcontext* ctx);
 
 
 //
 // Text
 //
 // NanoVG allows you to load .ttf files and use the font to render text.
 //
 // The appearance of the text can be defined by setting the current text style
 // and by specifying the fill color. Common text and font settings such as
 // font size, letter spacing and text align are supported. Font blur allows you
 // to create simple text effects such as drop shadows.
 //
 // At render time the font face can be set based on the font handles or name.
 //
 // Font measure functions return values in local space, the calculations are
 // carried in the same resolution as the final rendering. This is done because
 // the text glyph positions are snapped to the nearest pixels sharp rendering.
 //
 // The local space means that values are not rotated or scale as per the current
 // transformation. For example if you set font size to 12, which would mean that
 // line height is 16, then regardless of the current scaling and rotation, the
 // returned line height is always 16. Some measures may vary because of the scaling
 // since aforementioned pixel snapping.
 //
 // While this may sound a little odd, the setup allows you to always render the
 // same way regardless of scaling. I.e. following works regardless of scaling:
 //
 //		const char* txt = "Text me up.";
 //		nvgTextBounds(vg, x,y, txt, NULL, bounds);
 //		nvgBeginPath(vg);
 //		nvgRoundedRect(vg, bounds[0],bounds[1], bounds[2]-bounds[0], bounds[3]-bounds[1]);
 //		nvgFill(vg);
 //
 // Note: currently only solid color fill is supported for text.
 
 // Creates font by loading it from the disk from specified file name.
 // Returns handle to the font.
 int nvgCreateFont(NVGcontext* ctx, const char* name, const char* filename);
 
 // Creates font by loading it from the specified memory chunk.
 // Returns handle to the font.
 int nvgCreateFontMem(NVGcontext* ctx, const char* name, unsigned char* data, int ndata, int freeData);
 
 // Finds a loaded font of specified name, and returns handle to it, or -1 if the font is not found.
 int nvgFindFont(NVGcontext* ctx, const char* name);
 
 // Adds a fallback font by handle.
 int nvgAddFallbackFontId(NVGcontext* ctx, int baseFont, int fallbackFont);
 
 // Adds a fallback font by name.
 int nvgAddFallbackFont(NVGcontext* ctx, const char* baseFont, const char* fallbackFont);
 
 // Sets the font size of current text style.
 void nvgFontSize(NVGcontext* ctx, float size);
 
 // Sets the blur of current text style.
 void nvgFontBlur(NVGcontext* ctx, float blur);
 
 // Sets the letter spacing of current text style.
 void nvgTextLetterSpacing(NVGcontext* ctx, float spacing);
 
 // Sets the proportional line height of current text style. The line height is specified as multiple of font size.
 void nvgTextLineHeight(NVGcontext* ctx, float lineHeight);
 
 // Sets the text align of current text style, see NVGalign for options.
 void nvgTextAlign(NVGcontext* ctx, int align);
 
 // Sets the font face based on specified id of current text style.
 void nvgFontFaceId(NVGcontext* ctx, int font);
 
 // Sets the font face based on specified name of current text style.
 void nvgFontFace(NVGcontext* ctx, const char* font);
 
 // Draws text string at specified location. If end is specified only the sub-string up to the end is drawn.
 float nvgText(NVGcontext* ctx, float x, float y, const char* string, const char* end);
 
 // Draws multi-line text string at specified location wrapped at the specified width. If end is specified only the sub-string up to the end is drawn.
 // White space is stripped at the beginning of the rows, the text is split at word boundaries or when new-line characters are encountered.
 // Words longer than the max width are slit at nearest character (i.e. no hyphenation).
 void nvgTextBox(NVGcontext* ctx, float x, float y, float breakRowWidth, const char* string, const char* end);
 
 // Measures the specified text string. Parameter bounds should be a pointer to float[4],
 // if the bounding box of the text should be returned. The bounds value are [xmin,ymin, xmax,ymax]
 // Returns the horizontal advance of the measured text (i.e. where the next character should drawn).
 // Measured values are returned in local coordinate space.
 float nvgTextBounds(NVGcontext* ctx, float x, float y, const char* string, const char* end, float* bounds);
 
 // Measures the specified multi-text string. Parameter bounds should be a pointer to float[4],
 // if the bounding box of the text should be returned. The bounds value are [xmin,ymin, xmax,ymax]
 // Measured values are returned in local coordinate space.
 void nvgTextBoxBounds(NVGcontext* ctx, float x, float y, float breakRowWidth, const char* string, const char* end, float* bounds);
 
 // Calculates the glyph x positions of the specified text. If end is specified only the sub-string will be used.
 // Measured values are returned in local coordinate space.
 int nvgTextGlyphPositions(NVGcontext* ctx, float x, float y, const char* string, const char* end, NVGglyphPosition* positions, int maxPositions);
 
 // Returns the vertical metrics based on the current text style.
 // Measured values are returned in local coordinate space.
 void nvgTextMetrics(NVGcontext* ctx, float* ascender, float* descender, float* lineh);
 
 // Breaks the specified text into lines. If end is specified only the sub-string will be used.
 // White space is stripped at the beginning of the rows, the text is split at word boundaries or when new-line characters are encountered.
 // Words longer than the max width are slit at nearest character (i.e. no hyphenation).
 int nvgTextBreakLines(NVGcontext* ctx, const char* string, const char* end, float breakRowWidth, NVGtextRow* rows, int maxRows);
 
 //
 // Internal Render API
 //
 enum NVGtexture {
 	NVG_TEXTURE_ALPHA = 0x01,
 	NVG_TEXTURE_RGBA = 0x02,
 };
 
 struct NVGscissor {
 	float xform[6];
 	float extent[2];
 };
 typedef struct NVGscissor NVGscissor;
 
 struct NVGvertex {
 	float x,y,u,v;
 };
 typedef struct NVGvertex NVGvertex;
 
 struct NVGpath {
 	int first;
 	int count;
 	unsigned char closed;
 	int nbevel;
 	NVGvertex* fill;
 	int nfill;
 	NVGvertex* stroke;
 	int nstroke;
 	int winding;
 	int convex;
 };
 typedef struct NVGpath NVGpath;
 
 struct NVGparams {
 	void* userPtr;
 	int edgeAntiAlias;
 	int (*renderCreate)(void* uptr);
 	int (*renderCreateTexture)(void* uptr, int type, int w, int h, int imageFlags, const unsigned char* data);
 	int (*renderDeleteTexture)(void* uptr, int image);
 	int (*renderUpdateTexture)(void* uptr, int image, int x, int y, int w, int h, const unsigned char* data);
 	int (*renderGetTextureSize)(void* uptr, int image, int* w, int* h);
 	void (*renderViewport)(void* uptr, float width, float height, float devicePixelRatio);
 	void (*renderCancel)(void* uptr);
 	void (*renderFlush)(void* uptr);
 	void (*renderFill)(void* uptr, NVGpaint* paint, NVGcompositeOperationState compositeOperation, NVGscissor* scissor, float fringe, const float* bounds, const NVGpath* paths, int npaths);
 	void (*renderStroke)(void* uptr, NVGpaint* paint, NVGcompositeOperationState compositeOperation, NVGscissor* scissor, float fringe, float strokeWidth, const NVGpath* paths, int npaths);
 	void (*renderTriangles)(void* uptr, NVGpaint* paint, NVGcompositeOperationState compositeOperation, NVGscissor* scissor, const NVGvertex* verts, int nverts);
 	void (*renderDelete)(void* uptr);
 };
 typedef struct NVGparams NVGparams;
 
 // Constructor and destructor, called by the render back-end.
 NVGcontext* nvgCreateInternal(NVGparams* params);
 void nvgDeleteInternal(NVGcontext* ctx);
 
 NVGparams* nvgInternalParams(NVGcontext* ctx);
 
 // Debug function to dump cached path data.
 void nvgDebugDumpPathCache(NVGcontext* ctx);
 
 #ifdef _MSC_VER
 #pragma warning(pop)
 #endif
 
 #define NVG_NOTUSED(v) for (;;) { (void)(1 ? (void)0 : ( (void)(v) ) ); break; }
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif // NANOVG_H