diff --git a/src/nanovg.c b/src/nanovg.c index 43371ec..734e12d 100644 --- a/src/nanovg.c +++ b/src/nanovg.c @@ -66,6 +66,7 @@ enum NVGpointFlags }; struct NVGstate { + NVGcompositeOperationState compositeOperation; NVGpaint fill; NVGpaint stroke; float strokeWidth; @@ -203,6 +204,79 @@ static void nvg__setDevicePixelRatio(NVGcontext* ctx, float ratio) ctx->devicePxRatio = ratio; } +static NVGcompositeOperationState nvg__compositeOperationState(int op) +{ + int sfactor, dfactor; + + if (op == NVG_SOURCE_OVER) + { + sfactor = NVG_ONE; + dfactor = NVG_ONE_MINUS_SRC_ALPHA; + } + else if (op == NVG_SOURCE_IN) + { + sfactor = NVG_DST_ALPHA; + dfactor = NVG_ZERO; + } + else if (op == NVG_SOURCE_OUT) + { + sfactor = NVG_ONE_MINUS_DST_ALPHA; + dfactor = NVG_ZERO; + } + else if (op == NVG_ATOP) + { + sfactor = NVG_DST_ALPHA; + dfactor = NVG_ONE_MINUS_SRC_ALPHA; + } + else if (op == NVG_DESTINATION_OVER) + { + sfactor = NVG_ONE_MINUS_DST_ALPHA; + dfactor = NVG_ONE; + } + else if (op == NVG_DESTINATION_IN) + { + sfactor = NVG_ZERO; + dfactor = NVG_SRC_ALPHA; + } + else if (op == NVG_DESTINATION_OUT) + { + sfactor = NVG_ZERO; + dfactor = NVG_ONE_MINUS_SRC_ALPHA; + } + else if (op == NVG_DESTINATION_ATOP) + { + sfactor = NVG_ONE_MINUS_DST_ALPHA; + dfactor = NVG_SRC_ALPHA; + } + else if (op == NVG_LIGHTER) + { + sfactor = NVG_ONE; + dfactor = NVG_ONE; + } + else if (op == NVG_COPY) + { + sfactor = NVG_ONE; + dfactor = NVG_ZERO; + } + else if (op == NVG_XOR) + { + sfactor = NVG_ONE_MINUS_DST_ALPHA; + dfactor = NVG_ONE_MINUS_SRC_ALPHA; + } + + NVGcompositeOperationState state; + state.srcRGB = sfactor; + state.dstRGB = dfactor; + state.srcAlpha = sfactor; + state.dstAlpha = dfactor; + return state; +} + +static NVGstate* nvg__getState(NVGcontext* ctx) +{ + return &ctx->states[ctx->nstates-1]; +} + NVGcontext* nvgCreateInternal(NVGparams* params) { FONSparams fontParams; @@ -310,7 +384,8 @@ void nvgCancelFrame(NVGcontext* ctx) void nvgEndFrame(NVGcontext* ctx) { - ctx->params.renderFlush(ctx->params.userPtr); + NVGstate* state = nvg__getState(ctx); + ctx->params.renderFlush(ctx->params.userPtr, state->compositeOperation); if (ctx->fontImageIdx != 0) { int fontImage = ctx->fontImages[ctx->fontImageIdx]; int i, j, iw, ih; @@ -433,12 +508,6 @@ NVGcolor nvgHSLA(float h, float s, float l, unsigned char a) return col; } - -static NVGstate* nvg__getState(NVGcontext* ctx) -{ - return &ctx->states[ctx->nstates-1]; -} - void nvgTransformIdentity(float* t) { t[0] = 1.0f; t[1] = 0.0f; @@ -571,6 +640,7 @@ void nvgReset(NVGcontext* ctx) nvg__setPaintColor(&state->fill, nvgRGBA(255,255,255,255)); nvg__setPaintColor(&state->stroke, nvgRGBA(0,0,0,255)); + state->compositeOperation = nvg__compositeOperationState(NVG_SOURCE_OVER); state->strokeWidth = 1.0f; state->miterLimit = 10.0f; state->lineCap = NVG_BUTT; @@ -939,6 +1009,30 @@ void nvgResetScissor(NVGcontext* ctx) state->scissor.extent[1] = -1.0f; } +// Global composite operation. +void nvgGlobalCompositeOperation(NVGcontext* ctx, int op) +{ + NVGstate* state = nvg__getState(ctx); + state->compositeOperation = nvg__compositeOperationState(op); +} + +void nvgGlobalCompositeBlendFunc(NVGcontext* ctx, int sfactor, int dfactor) +{ + nvgGlobalCompositeBlendFuncSeparate(ctx, sfactor, dfactor, sfactor, dfactor); +} + +void nvgGlobalCompositeBlendFuncSeparate(NVGcontext* ctx, int srcRGB, int dstRGB, int srcAlpha, int dstAlpha) +{ + NVGcompositeOperationState op; + op.srcRGB = srcRGB; + op.dstRGB = dstRGB; + op.srcAlpha = srcAlpha; + op.dstAlpha = dstAlpha; + + NVGstate* state = nvg__getState(ctx); + state->compositeOperation = op; +} + static int nvg__ptEquals(float x1, float y1, float x2, float y2, float tol) { float dx = x2 - x1; diff --git a/src/nanovg.h b/src/nanovg.h index 603b8e3..80b256d 100644 --- a/src/nanovg.h +++ b/src/nanovg.h @@ -79,10 +79,46 @@ enum NVGalign { // 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. + 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. @@ -123,6 +159,22 @@ 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 // @@ -183,7 +235,7 @@ void nvgReset(NVGcontext* ctx); // 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(). +// Current render style can be saved and restored using nvgSave() and nvgRestore(). // Sets current stroke style to a solid color. void nvgStrokeColor(NVGcontext* ctx, NVGcolor color); @@ -231,7 +283,7 @@ void nvgGlobalAlpha(NVGcontext* ctx, float alpha); // 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(). +// Current coordinate system (transformation) can be saved and restored using nvgSave() and nvgRestore(). // Resets current transform to a identity matrix. void nvgResetTransform(NVGcontext* ctx); @@ -368,7 +420,7 @@ NVGpaint nvgImagePattern(NVGcontext* ctx, float ox, float oy, float ex, float ey // 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. +// 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. @@ -423,7 +475,7 @@ void nvgArcTo(NVGcontext* ctx, float x1, float y1, float x2, float y2, float rad // Closes current sub-path with a line segment. void nvgClosePath(NVGcontext* ctx); -// Sets the current sub-path winding, see NVGwinding and NVGsolidity. +// 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, @@ -440,7 +492,7 @@ void nvgRoundedRect(NVGcontext* ctx, float x, float y, float w, float h, float r // Creates new ellipse shaped sub-path. void nvgEllipse(NVGcontext* ctx, float cx, float cy, float rx, float ry); -// Creates new circle shaped sub-path. +// Creates new circle shaped sub-path. void nvgCircle(NVGcontext* ctx, float cx, float cy, float r); // Fills the current path with current fill style. @@ -503,7 +555,7 @@ 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. +// 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. @@ -590,7 +642,7 @@ struct NVGparams { int (*renderGetTextureSize)(void* uptr, int image, int* w, int* h); void (*renderViewport)(void* uptr, int width, int height, float devicePixelRatio); void (*renderCancel)(void* uptr); - void (*renderFlush)(void* uptr); + void (*renderFlush)(void* uptr, NVGcompositeOperationState compositeOperation); void (*renderFill)(void* uptr, NVGpaint* paint, NVGscissor* scissor, float fringe, const float* bounds, const NVGpath* paths, int npaths); void (*renderStroke)(void* uptr, NVGpaint* paint, NVGscissor* scissor, float fringe, float strokeWidth, const NVGpath* paths, int npaths); void (*renderTriangles)(void* uptr, NVGpaint* paint, NVGscissor* scissor, const NVGvertex* verts, int nverts); diff --git a/src/nanovg_gl.h b/src/nanovg_gl.h index 7580af1..fa3c992 100644 --- a/src/nanovg_gl.h +++ b/src/nanovg_gl.h @@ -1072,7 +1072,38 @@ static void glnvg__renderCancel(void* uptr) { gl->nuniforms = 0; } -static void glnvg__renderFlush(void* uptr) +static GLenum glnvg_convertBlendFuncFactor(int factor) +{ + if (factor == NVG_ZERO) + return GL_ZERO; + if (factor == NVG_ONE) + return GL_ONE; + if (factor == NVG_SRC_COLOR) + return GL_SRC_COLOR; + if (factor == NVG_ONE_MINUS_SRC_COLOR) + return GL_ONE_MINUS_SRC_COLOR; + if (factor == NVG_DST_COLOR) + return GL_DST_COLOR; + if (factor == NVG_ONE_MINUS_DST_COLOR) + return GL_ONE_MINUS_DST_COLOR; + if (factor == NVG_SRC_ALPHA) + return GL_SRC_ALPHA; + if (factor == NVG_ONE_MINUS_SRC_ALPHA) + return GL_ONE_MINUS_SRC_ALPHA; + if (factor == NVG_DST_ALPHA) + return GL_DST_ALPHA; + if (factor == NVG_ONE_MINUS_DST_ALPHA) + return GL_ONE_MINUS_DST_ALPHA; + if (factor == NVG_SRC_ALPHA_SATURATE) + return GL_SRC_ALPHA_SATURATE; +} + +static void glnvg__blendCompositeOperation(NVGcompositeOperationState op) +{ + glBlendFuncSeparate(glnvg_convertBlendFuncFactor(op.srcRGB), glnvg_convertBlendFuncFactor(op.dstRGB), glnvg_convertBlendFuncFactor(op.srcAlpha), glnvg_convertBlendFuncFactor(op.dstAlpha)); +} + +static void glnvg__renderFlush(void* uptr, NVGcompositeOperationState compositeOperation) { GLNVGcontext* gl = (GLNVGcontext*)uptr; int i; @@ -1082,7 +1113,7 @@ static void glnvg__renderFlush(void* uptr) // Setup require GL state. glUseProgram(gl->shader.prog); - glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA); + glnvg__blendCompositeOperation(compositeOperation); glEnable(GL_CULL_FACE); glCullFace(GL_BACK); glFrontFace(GL_CCW);