#include "private.h"
#include "window.h"
#include "drawing.h"
static double *path;
static size_t pathSize;
static size_t pathAllocated;
static HeliDrawingState statesStack[1024];
static int statesStackIndex = 0;
typedef struct _HeliStrokePoint {
double x, y, dx, dy;
} HeliStrokePoint;
typedef struct _HeliStroke {
HeliStrokePoint *points;
int count;
int allocatedCount;
} HeliStroke;
static void endPath(int close, int stroke, int fill, int fillSimple);
static void closePathSimple()
{ endPath(TRUE, TRUE, FALSE, TRUE); }
static int isStrokeSolid(HeliDrawingState *state, double *outAABorder) {
if ( state->strokeColor[3] >= 1.0 - HELI_PRECISION
&& state->strokeWidth > HELI_PRECISION
&& (!state->strokeTexture.animation || !animationGetGLTexId(state->strokeTexture.animation)) )
{
double aaBorder = heliGLGetAAResolution();
if (outAABorder) *outAABorder = aaBorder;
if (aaBorder > HELI_PRECISION && aaBorder < state->strokeWidth)
return TRUE;
} else
if (outAABorder) {
*outAABorder = heliGLGetAAResolution();
}
return FALSE;
}
void heliDrawingApplyTexture(double *color, HeliTextureState *state) {
glColor4dv(color);
unsigned int texid = state->animation ? animationGetGLTexId(state->animation) : 0;
if (texid) {
HeliPair *pair = heliUIntGet(&heliDrawingFramebuffersToFlush, texid);
if (pair) framebufferFlush((Framebuffer)pair->value);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, texid);
glEnable(GL_TEXTURE_GEN_S);
glEnable(GL_TEXTURE_GEN_T);
if (state->fixed) {
unsigned int mode;
glGetIntegerv(GL_MATRIX_MODE, (int*)&mode);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
glTexGendv(GL_S, GL_EYE_PLANE, state->genx);
glTexGendv(GL_T, GL_EYE_PLANE, state->geny);
glPopMatrix();
glMatrixMode(mode);
} else {
glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
glTexGendv(GL_S, GL_OBJECT_PLANE, state->genx);
glTexGendv(GL_T, GL_OBJECT_PLANE, state->geny);
}
}
}
void heliDrawingResetTexture() {
glDisable(GL_TEXTURE_GEN_S);
glDisable(GL_TEXTURE_GEN_T);
glBindTexture(GL_TEXTURE_2D, 0);
glDisable(GL_TEXTURE_2D);
glColor4d(1, 1, 1, 1);
}
static void initTextureState(HeliTextureState *s, Animation animation, double x, double y, double width, double height, int fixed) {
s->animation = animation;
double kx = fabs(width) > HELI_PRECISION ? 1/width
: width < 0 ? -HELI_PRECISION : HELI_PRECISION;
double ky = fabs(height) > HELI_PRECISION ? 1/height
: height < 0 ? -HELI_PRECISION : HELI_PRECISION;
double genx[4] = {kx, 0, 0, -x*kx};
double geny[4] = {0, ky, 0, -y*ky};
if (fixed) {
s->fixed = TRUE;
double m[4][4];
glGetDoublev(GL_MODELVIEW_MATRIX, *m);
for(int i = 0; i < 4; ++i) {
s->genx[i] = genx[0]*m[0][i] + genx[1]*m[1][i] + genx[2]*m[2][i] + genx[3]*m[3][i];
s->geny[i] = geny[0]*m[0][i] + geny[1]*m[1][i] + geny[2]*m[2][i] + geny[3]*m[3][i];
}
} else {
s->fixed = FALSE;
memcpy(s->genx, genx, sizeof(genx));
memcpy(s->geny, geny, sizeof(geny));
}
}
void background(unsigned int colorCode) {
double color[4];
heliColorToDouble(colorCode, color);
glClearColor(color[0], color[1], color[2], color[3]);
}
void clear()
{ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT); }
void fill(unsigned int colorCode)
{ heliColorToDouble(colorCode, heliDrawingGetState()->fillColor); }
void fillTexture(Animation animation, double x, double y, double width, double height, int fixed)
{ initTextureState(&heliDrawingGetState()->fillTexture, animation, x, y, width, height, fixed); }
void noFillColor()
{ fill(0); }
void noFillTexture()
{ fillTexture(NULL, 0, 0, 1, 1, FALSE); }
void noFill()
{ noFillColor(); noFillTexture(); }
void stroke(unsigned int colorCode)
{ heliColorToDouble(colorCode, heliDrawingGetState()->strokeColor); }
void strokeTexture(Animation animation, double x, double y, double width, double height, int fixed)
{ initTextureState(&heliDrawingGetState()->strokeTexture, animation, x, y, width, height, fixed); }
void noStrokeColor()
{ stroke(0); }
void noStrokeTexture()
{ strokeTexture(NULL, 0, 0, 1, 1, FALSE); }
void noStroke()
{ noStrokeColor(); noStrokeTexture(); }
void strokeWidth(double width)
{ heliDrawingGetState()->strokeWidth = width; }
void enableAntialiasing()
{ heliDrawingGetState()->antialiasing = TRUE; }
void disableAntialiasing()
{ heliDrawingGetState()->antialiasing = FALSE; }
const char* rgba(double r, double g, double b, double a) {
static char buf[1024];
snprintf(buf, sizeof(buf) - 1, "%f %f %f %f", r, g, b, a);
return buf;
}
const char* rgb(double r, double g, double b)
{ return rgba(r, g, b, 1); }
void translate(double x, double y)
{ glTranslated(x, y, 0); }
void rotate(double angle)
{ glRotated(angle, 0, 0, 1); }
void scale(double x, double y)
{ glScaled(x, y, 1); }
void zoom(double z)
{ scale(z, z); }
void noTransform()
{ glLoadIdentity(); }
void cliprect(double x, double y, double width, double height) {
double eq[4][4] = {
{ 1, 0, 0, -x },
{-1, 0, 0, x+width },
{ 0, 1, 0, -y },
{ 0,-1, 0, y+height } };
for(int i = 0; i < 4; ++i) {
glEnable(GL_CLIP_PLANE0 + i);
glClipPlane(GL_CLIP_PLANE0 + i, eq[i]);
}
}
void noClip()
{ for(int i = 0; i < 4; ++i) glDisable(GL_CLIP_PLANE0 + i); }
void projectionByViewport() {
unsigned int framebuffer_id = 0;
glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, (int*)&framebuffer_id);
int vp[4] = {};
glGetIntegerv(GL_VIEWPORT, vp);
unsigned int mode;
glGetIntegerv(GL_MATRIX_MODE, (int*)&mode);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (framebuffer_id)
glOrtho(0, vp[2], 0, vp[3], -1.0, 1.0);
else
glOrtho(0, vp[2], vp[3], 0, -1.0, 1.0);
glMatrixMode(mode);
}
void viewportByFramebuffer(Framebuffer framebuffer) {
if (framebuffer)
glViewport(0, 0, framebufferGetWidth(framebuffer), framebufferGetHeight(framebuffer));
else
glViewport(0, 0, windowGetWidth(), windowGetHeight());
}
void viewportByWindow()
{ viewportByFramebuffer(NULL); }
void targetEx(Framebuffer framebuffer, int updateViewport, int updateProjection) {
if (framebuffer) {
if (heliGLBindFramebufferPtr) {
unsigned int id = framebufferGetGLId(framebuffer);
heliGLBindFramebufferPtr(GL_READ_FRAMEBUFFER, id);
heliGLBindFramebufferPtr(GL_DRAW_FRAMEBUFFER, id);
unsigned int texid = framebufferGetGLTexId(framebuffer);
if (texid) heliUIntAdd(&heliDrawingFramebuffersToFlush, texid, framebuffer, NULL);
}
if (updateViewport) {
viewportByFramebuffer(framebuffer);
if (updateProjection) projectionByViewport();
}
} else {
if (heliGLBindFramebufferPtr) {
heliGLBindFramebufferPtr(GL_READ_FRAMEBUFFER, heliGLWindowFramebufferReadId);
heliGLBindFramebufferPtr(GL_DRAW_FRAMEBUFFER, heliGLWindowFramebufferDrawId);
}
if (updateViewport) {
viewportByWindow();
if (updateProjection) projectionByViewport();
}
}
}
void target(Framebuffer framebuffer)
{ targetEx(framebuffer, TRUE, TRUE); }
void noTarget()
{ target(NULL); }
void rect(double x, double y, double width, double height) {
resetPath();
HeliDrawingState *s = heliDrawingGetState();
double aaBorder = 0;
int antialiasing = s->antialiasing && !isStrokeSolid(s, &aaBorder);
heliFillRectSimple(x, y, x+width, y+height, aaBorder, antialiasing);
moveTo(x, y);
lineTo(x + width, y);
lineTo(x + width, y + height);
lineTo(x, y + height);
endPath(TRUE, TRUE, FALSE, FALSE);
}
void rectRounded(double x, double y, double width, double height, double radius) {
radius = fabs(radius);
if (radius < HELI_PRECISION)
{ rect(x, y, width, height); return; }
double x0 = x, y0 = y, x1 = x + width, y1 = y + height;
if (width < 0) { x0 = x1; x1 = x; }
if (height < 0) { y0 = y1; y1 = y; }
double rw = 0.5*fabs(width);
double rh = 0.5*fabs(height);
if (radius > rw) radius = rw;
if (radius > rh) radius = rh;
int lw = fabs(rw - radius) > HELI_PRECISION;
int lh = fabs(rh - radius) > HELI_PRECISION;
double r2 = radius + radius;
if (lw && lh) {
resetPath();
arcPath( x0 , y0 , r2, r2, -180, -90 );
arcPath( x1-r2, y0 , r2, r2, -90, 0 );
arcPath( x1-r2, y1-r2, r2, r2, 0, 90 );
arcPath( x0 , y1-r2, r2, r2, 90, 180 );
closePath();
} else
if (lw) {
resetPath();
arcPath( x0 , y0, r2, y1-y0, 90, 270 );
arcPath( x1-r2, y0, r2, y1-y0, -90, 90 );
closePath();
} else
if (lh) {
resetPath();
arcPath( x0, y0 , x1-x0, y0+r2, -180, 0 );
arcPath( x0, y1-r2, x1-x0, y1 , 0, 180 );
closePath();
} else {
circle(0.5*(x0 + x1), 0.5*(y0 + y1), radius);
}
}
void rectTextured(Animation animation, double x, double y, double width, double height) {
saveState();
fillTexture(animation, x, y, width, height, FALSE);
rect(x, y, width, height);
restoreState();
}
void line(double x1, double y1, double x2, double y2) {
resetPath();
moveTo(x1, y1);
lineTo(x2, y2);
strokePath();
}
void ellipse(double x, double y, double width, double height) {
resetPath();
if (fabs(fabs(width) - fabs(height)) <= HELI_PRECISION) {
HeliDrawingState *s = heliDrawingGetState();
double aaBorder = 0;
int antialiasing = s->antialiasing && !isStrokeSolid(s, &aaBorder);
heliFillCircleSimple(x + 0.5*width, y + 0.5*height, 0.5*width, aaBorder, antialiasing);
arcPath(x, y, width, height, 0, 360);
endPath(TRUE, TRUE, FALSE, FALSE);
} else {
arcPath(x, y, width, height, 0, 360);
closePathSimple();
}
}
void circle(double x, double y, double radius)
{ ellipse(x - radius, y - radius, 2*radius, 2*radius); }
void point(double x, double y) {
saveStateEx(STATE_FILL | STATE_STROKE);
HeliDrawingState *s = heliDrawingGetState();
memcpy(&s->fillColor, &s->strokeColor, sizeof(s->fillColor));
memcpy(&s->fillTexture, &s->strokeTexture, sizeof(s->fillTexture));
noStroke();
if (s->strokeWidth > HELI_PRECISION)
ellipse(x - s->strokeWidth*0.5, y - s->strokeWidth*0.5, s->strokeWidth, s->strokeWidth);
restoreState();
}
void arcPath(double x, double y, double w, double h, double start, double stop) {
w *= 0.5; x += w;
h *= 0.5; y += h;
if (fabs(w) < HELI_PRECISION || fabs(h) < HELI_PRECISION) return;
double step = fabs(w) > fabs(h) ? 1/fabs(w) : 1/fabs(h);
if (step > PI/180) step = PI/180;
start *= PI/180;
stop *= PI/180;
double a = start;
if (start < stop) {
while(1) {
if (a > stop) a = stop;
lineTo(x + cos(a)*w, y + sin(a)*h);
if (a == stop) break;
a += step;
}
} else {
while(1) {
if (a < stop) a = stop;
lineTo(x + cos(a)*w, y + sin(a)*h);
if (a == stop) break;
a -= step;
}
}
}
void arc(double x, double y, double w, double h, double start, double stop) {
resetPath();
arcPath(x, y, w, h, start, stop);
strokePath();
}
void regularPolygon(double x, double y, int sides, double radius, double angle) {
angle *= PI/180.0;
resetPath();
moveTo(x + radius*cos(angle), y + radius*sin(angle));
for(int i = 1; i < sides; ++i) {
double a = i*2*PI/sides + angle;
lineTo(x + radius*cos(a), y + radius*sin(a));
}
closePathSimple();
}
void resetPath()
{ pathSize = 0; }
void heliFillCircleSimple(double x, double y, double r, double aaBorder, int antialiasing) {
r = fabs(r);
if (r < HELI_PRECISION) return;
HeliDrawingState *s = heliDrawingGetState();
if (s->fillColor[3] <= HELI_PRECISION) return;
if (!s->antialiasing) antialiasing = FALSE;
heliDrawingApplyTexture(s->fillColor, &s->fillTexture);
double step = 1/r;
if (step > PI/180) step = PI/180;
if (!antialiasing || aaBorder < HELI_PRECISION) {
if (antialiasing) glEnable(GL_MULTISAMPLE);
glBegin(GL_TRIANGLE_FAN);
for(double a = 0; a < 2*PI; a += step) glVertex2d(x + cos(a)*r, y + sin(a)*r);
glEnd();
glDisable(GL_MULTISAMPLE);
} else {
double color[4] = { s->fillColor[0], s->fillColor[1], s->fillColor[2], s->fillColor[3] };
double sideColor[4] = { color[0], color[1], color[2], 0 };
double r1 = r + 0.5*aaBorder;
double r0 = r - 0.5*aaBorder;
if (r0 > HELI_PRECISION) {
glBegin(GL_TRIANGLE_FAN);
for(double a = 0; a < 2*PI; a += step) glVertex2d(x + cos(a)*r0, y + sin(a)*r0);
glEnd();
} else {
color[3] *= r/aaBorder;
r0 = 0;
}
glBegin(GL_TRIANGLE_STRIP);
for(double a = step; a < 2*PI; a += step) {
double s = sin(a), c = cos(a);
glColor4dv(color);
glVertex2d(x + c*r0, y + s*r0);
glColor4dv(sideColor);
glVertex2d(x + c*r1, y + s*r1);
}
glEnd();
}
}
void heliFillRectSimple(double x0, double y0, double x1, double y1, double aaBorder, int antialiasing) {
if (fabs(x1 - x0) < HELI_PRECISION || fabs(y1 - y0) < HELI_PRECISION) return;
HeliDrawingState *s = heliDrawingGetState();
if (s->fillColor[3] <= HELI_PRECISION) return;
if (!s->antialiasing) antialiasing = FALSE;
heliDrawingApplyTexture(s->fillColor, &s->fillTexture);
if (!antialiasing || aaBorder <= HELI_PRECISION) {
if (antialiasing) glEnable(GL_MULTISAMPLE);
glBegin(GL_QUADS);
glVertex2d(x0, y0);
glVertex2d(x1, y0);
glVertex2d(x1, y1);
glVertex2d(x0, y1);
glEnd();
glDisable(GL_MULTISAMPLE);
} else {
double color[4] = { s->fillColor[0], s->fillColor[1], s->fillColor[2], s->fillColor[3] };
double sideColor[4] = { color[0], color[1], color[2], 0 };
if (x1 < x0) { double x = x0; x0 = x1; x1 = x; }
if (y1 < y0) { double y = y0; y0 = y1; y1 = y; }
double x = (x1 + x0)*0.5;
double y = (y1 + y0)*0.5;
double hw = (x1 - x0)*0.5;
double hh = (y1 - y0)*0.5;
double k0 = 0;
double k1 = 0.5;
double w0 = hw - k0*aaBorder;
double w1 = hw + k1*aaBorder;
if (w0 < HELI_PRECISION) w0 = 0;
double h0 = hh - k0*aaBorder;
double h1 = hh + k1*aaBorder;
if (h0 < HELI_PRECISION) h0 = 0;
const double k = (w0 ? 1 : w1/((k0+k1)*aaBorder))
* (h0 ? 1 : h1/((k0+k1)*aaBorder));
color[3] *= k;
const int vcnt = 14;
const double vertices[][2] = {
{ x-w1, y-h1 }, { x-w0, y-h0 },
{ x+w1, y-h1 }, { x+w0, y-h0 },
{ x+w1, y+h1 }, { x+w0, y+h0 },
{ x-w1, y+h1 }, { x-w0, y+h0 },
{ x-w1, y-h1 }, { x-w0, y-h0 },
{ x-w0, y-h0 },
{ x+w0, y-h0 },
{ x-w0, y+h0 },
{ x+w0, y+h0 } };
const double *colors[] = {
sideColor, color,
sideColor, color,
sideColor, color,
sideColor, color,
sideColor, color,
color,
color,
color,
color };
glBegin(GL_TRIANGLE_STRIP);
for(int i = 0; i < vcnt; ++i) {
glColor4dv(colors[i]);
glVertex2dv(vertices[i]);
}
glEnd();
}
heliDrawingResetTexture();
}
static void drawFillSimple(int antialiasing) {
HeliDrawingState *s = heliDrawingGetState();
if (s->fillColor[3] <= HELI_PRECISION) return;
if (pathSize < 6) return;
heliDrawingApplyTexture(s->fillColor, &s->fillTexture);
if (antialiasing && s->antialiasing) glEnable(GL_MULTISAMPLE);
glBegin(GL_TRIANGLE_FAN);
for(int i = 0; i < pathSize; i += 2)
glVertex2dv(&path[i]);
glEnd();
glDisable(GL_MULTISAMPLE);
heliDrawingResetTexture();
}
static void drawFill(int antialiasing) {
HeliDrawingState *s = heliDrawingGetState();
if (s->fillColor[3] <= HELI_PRECISION) return;
if (pathSize < 6) return;
double l = path[0], r = l;
double t = path[1], b = t;
for(int i = 2; i < pathSize; i += 2) {
if (l > path[i]) l = path[i];
if (r < path[i]) r = path[i];
if (t > path[i + 1]) t = path[i + 1];
if (b < path[i + 1]) b = path[i + 1];
}
if ( r - l <= HELI_PRECISION
|| b - t <= HELI_PRECISION) return;
l -= 1; r += 1;
t -= 1; b += 1;
if (antialiasing && s->antialiasing) glEnable(GL_MULTISAMPLE);
glEnable(GL_STENCIL_TEST);
glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
glStencilOp(GL_ZERO, GL_ZERO, GL_ZERO);
glBegin(GL_QUADS);
glVertex2d(l, t);
glVertex2d(r, t);
glVertex2d(r, b);
glVertex2d(l, b);
glEnd();
if (heliGLStencilOpSeparatePtr) {
heliGLStencilOpSeparatePtr(GL_FRONT, GL_INCR_WRAP, GL_INCR_WRAP, GL_INCR_WRAP);
heliGLStencilOpSeparatePtr(GL_BACK, GL_DECR_WRAP, GL_DECR_WRAP, GL_DECR_WRAP);
glBegin(GL_TRIANGLE_FAN);
for(int i = 0; i < pathSize; i += 2)
glVertex2dv(&path[i]);
glEnd();
} else {
glEnable(GL_CULL_FACE);
glStencilOp(GL_DECR_WRAP, GL_DECR_WRAP, GL_DECR_WRAP);
glCullFace(GL_FRONT);
glBegin(GL_TRIANGLE_FAN);
for(int i = 0; i < pathSize; i += 2)
glVertex2dv(&path[i]);
glEnd();
glStencilOp(GL_INCR_WRAP, GL_INCR_WRAP, GL_INCR_WRAP);
glCullFace(GL_BACK);
glBegin(GL_TRIANGLE_FAN);
for(int i = 0; i < pathSize; i += 2)
glVertex2dv(&path[i]);
glEnd();
glDisable(GL_CULL_FACE);
}
glStencilFunc(GL_NOTEQUAL, 0, -1u);
glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
heliDrawingApplyTexture(s->fillColor, &s->fillTexture);
glBegin(GL_QUADS);
glVertex2d(l, t);
glVertex2d(r, t);
glVertex2d(r, b);
glVertex2d(l, b);
glEnd();
heliDrawingResetTexture();
glStencilFunc(GL_ALWAYS, 0, -1u);
glDisable(GL_STENCIL_TEST);
glDisable(GL_MULTISAMPLE);
}
static void strokeAddPoint(HeliStroke *stroke, double x, double y, double dx, double dy) {
if (stroke->allocatedCount < stroke->count + 1) {
stroke->allocatedCount += stroke->allocatedCount/4 + 32;
stroke->points = realloc(stroke->points, stroke->allocatedCount*4*sizeof(*stroke->points));
memset(stroke->points + stroke->count, 0, (stroke->allocatedCount - stroke->count)*sizeof(*stroke->points));
}
HeliStrokePoint *p = &stroke->points[ stroke->count++ ];
p->x = x;
p->y = y;
p->dx = dx;
p->dy = dy;
}
static void strokeAddCornerSub(HeliStroke *stroke, double dx, double dy, double precisionSqr, int level) {
assert(stroke->count > 0);
HeliStrokePoint *prev = stroke->points + stroke->count - 1;
if (level > 0) {
double distx = dx - prev->dx;
double disty = dy - prev->dy;
if (distx*distx + disty*disty > precisionSqr) {
double mx = prev->dx + dx;
double my = prev->dy + dy;
double lsqr = mx*mx + my*my;
if (lsqr > HELI_PRECISION_SQR) {
double kl = 1/sqrt(lsqr);
mx *= kl;
my *= kl;
strokeAddCornerSub(stroke, mx, my, precisionSqr, level-1);
strokeAddCornerSub(stroke, dx, dy, precisionSqr, level-1);
return;
}
}
}
strokeAddPoint(stroke, prev->x, prev->y, dx, dy);
}
static void strokeAddCorner(
HeliStroke *stroke,
double xp, double yp,
double x0, double y0,
double x1, double y1,
double precisionSqr )
{
double dx0 = x0 - xp;
double dy0 = y0 - yp;
double dx1 = x1 - x0;
double dy1 = y1 - y0;
double l0 = sqrt(dx0*dx0 + dy0*dy0);
double l1 = sqrt(dx1*dx1 + dy1*dy1);
assert(l0 > HELI_PRECISION);
assert(l1 > HELI_PRECISION);
double kl0 = 1/l0, kl1 = 1/l1;
double nx0 = dx0*kl0, ny0 = dy0*kl0;
double nx1 = dx1*kl1, ny1 = dy1*kl1;
assert(fabs(sqrt(nx0*nx0 + ny0*ny0) - 1) <= HELI_PRECISION);
assert(fabs(sqrt(nx1*nx1 + ny1*ny1) - 1) <= HELI_PRECISION);
double dot = nx0*ny1 - ny0*nx1;
if (dot > HELI_PRECISION) {
// round
strokeAddPoint(stroke, x0, y0, ny0, -nx0);
strokeAddCornerSub(stroke, ny1, -nx1, precisionSqr, 8);
} else
if (dot < -HELI_PRECISION) {
// corner
double dx = nx1 - nx0;
double dy = ny1 - ny0;
double kl = 1/sqrt(dx*dx + dy*dy);
double nx = dx*kl, ny = dy*kl;
double c = nx*nx1 + ny*ny1;
double cl = 1/sqrt(1 - c*c);
if (cl > 3) cl = 3;
strokeAddPoint(stroke, x0, y0, nx*cl, ny*cl);
} else {
// half circle
strokeAddPoint(stroke, x0, y0, ny0, -nx0);
strokeAddCornerSub(stroke, nx0, ny0, precisionSqr, 8);
strokeAddCornerSub(stroke, ny1, -nx1, precisionSqr, 8);
}
}
static void strokeDraw(HeliStroke *stroke, double w, double *color, int antialiasing) {
const double aaBorder = heliGLGetAAResolution();
if (antialiasing && aaBorder > HELI_PRECISION) {
double c0[4] = { color[0], color[1], color[2], 0 };
double c1[4] = { color[0], color[1], color[2], color[3] };
double w0 = w + 0.5*aaBorder;
double w1 = w - 0.5*aaBorder;
if (!(w1 > HELI_PRECISION)) {
c1[3] *= w0/aaBorder;
w1 = 0;
}
glBegin(GL_TRIANGLE_STRIP);
for(int i = 0; i < stroke->count; ++i) {
HeliStrokePoint *p = stroke->points + i;
glColor4dv(c0);
glVertex2d(p->x + p->dx*w0, p->y + p->dy*w0);
glColor4dv(c1);
glVertex2d(p->x + p->dx*w1, p->y + p->dy*w1);
}
glEnd();
if (w1 > 0) {
glColor4dv(c1);
glBegin(GL_TRIANGLE_STRIP);
for(int i = 0; i < stroke->count; ++i) {
HeliStrokePoint *p = stroke->points + i;
glVertex2d(p->x, p->y);
glVertex2d(p->x + p->dx*w1, p->y + p->dy*w1);
}
glEnd();
}
glColor4d(1, 1, 1, 1);
} else {
glColor4dv(color);
if (antialiasing) glEnable(GL_MULTISAMPLE);
glBegin(GL_TRIANGLE_STRIP);
for(int i = 0; i < stroke->count; ++i) {
HeliStrokePoint *p = stroke->points + i;
glVertex2d(p->x, p->y);
glVertex2d(p->x + p->dx*w, p->y + p->dy*w);
}
glEnd();
glDisable(GL_MULTISAMPLE);
glColor4d(1, 1, 1, 1);
}
}
static void drawStroke(int close) {
HeliDrawingState *s = heliDrawingGetState();
if (!(s->strokeColor[3] > HELI_PRECISION)) return;
if (!(s->strokeWidth > HELI_PRECISION)) return;
if (pathSize < 4) return;
HeliStroke stroke = {};
stroke.allocatedCount = pathSize;
stroke.points = calloc(stroke.allocatedCount, sizeof(*stroke.points));
double w = 0.5*s->strokeWidth;
double ps = heliGLGetPixelSize();
double precisionSqr = ps > HELI_PRECISION ? ps : 0.5*w;
precisionSqr *= 0.5;
precisionSqr *= precisionSqr;
heliDrawingApplyTexture(s->strokeColor, &s->strokeTexture);
if (close) {
for(int i = 0; i < pathSize; i += 2) {
int p = i > 0 ? i - 2 : pathSize - 2;
int n = i < pathSize - 2 ? i + 2 : 0;
strokeAddCorner(
&stroke,
path[p], path[p+1],
path[i], path[i+1],
path[n], path[n+1],
precisionSqr );
}
strokeAddPoint(
&stroke,
stroke.points[0].x,
stroke.points[0].y,
stroke.points[0].dx,
stroke.points[0].dy );
strokeDraw(&stroke, w, s->strokeColor, s->antialiasing);
stroke.count = 0;
for(int i = pathSize - 2; i >= 0; i -= 2) {
int p = i < pathSize - 2 ? i + 2 : 0;
int n = i > 0 ? i - 2 : pathSize - 2;
strokeAddCorner(
&stroke,
path[p], path[p+1],
path[i], path[i+1],
path[n], path[n+1],
precisionSqr );
}
strokeAddPoint(
&stroke,
stroke.points[0].x,
stroke.points[0].y,
stroke.points[0].dx,
stroke.points[0].dy );
strokeDraw(&stroke, w, s->strokeColor, s->antialiasing);
} else {
double px = 0, py = 0, nx = 0, ny = 0;
for(int i = 0; i < pathSize; i += 2) {
double x = path[i], y = path[i+1];
if (i > 0) { px = path[i-2]; py = path[i-1]; }
if (i < pathSize - 2) { nx = path[i+2]; ny = path[i+3]; }
if (i == 0) { px = x + y - ny; py = y + nx - x; }
if (i == pathSize - 2) { nx = x + py - y; ny = y + x - px; }
strokeAddCorner(&stroke, px, py, x, y, nx, ny, precisionSqr);
}
--stroke.count;
for(int i = pathSize - 2; i >= 0; i -= 2) {
double x = path[i], y = path[i+1];
if (i > 0) { nx = path[i-2]; ny = path[i-1]; }
if (i < pathSize - 2) { px = path[i+2]; py = path[i+3]; }
if (i == 0) { nx = x + py - y; ny = y + x - px; }
if (i == pathSize - 2) { px = x + y - ny; py = y + nx - x; }
strokeAddCorner(&stroke, px, py, x, y, nx, ny, precisionSqr);
}
memcpy(stroke.points + stroke.count - 1, stroke.points, sizeof(*stroke.points));
strokeDraw(&stroke, w, s->strokeColor, s->antialiasing);
}
heliDrawingResetTexture();
free(stroke.points);
}
static void pushPathPoint(double x, double y) {
if (pathAllocated < pathSize + 2) {
pathAllocated += pathAllocated/4 + 32;
path = realloc(path, pathAllocated*sizeof(*path));
memset(&path[pathSize], 0, (pathAllocated - pathSize)*sizeof(*path));
}
path[pathSize++] = x;
path[pathSize++] = y;
}
static void endPath(int close, int stroke, int fill, int fillSimple) {
int origPathSize = pathSize;
// remove duplicates
int removed = 0;
for(int i = 2; i < pathSize; i += 2) {
if ( fabs(path[i-removed-2] - path[i]) <= 2*HELI_PRECISION
&& fabs(path[i-removed-1] - path[i+1]) <= 2*HELI_PRECISION )
{
removed += 2;
} else
if (removed > 0) {
path[i-removed] = path[i];
path[i-removed+1] = path[i+1];
}
}
// remove tails duplicates
pathSize -= removed;
if ( pathSize >= 4
&& close
&& fabs(path[pathSize-2] - path[0]) <= 2*HELI_PRECISION
&& fabs(path[pathSize-1] - path[1]) <= 2*HELI_PRECISION )
pathSize -= 2;
// if shape convex?
if (pathSize >= 6 && fill && !fillSimple) {
int convex = TRUE;
int d = 0;
double x0 = path[pathSize-4];
double y0 = path[pathSize-3];
double x1 = path[pathSize-2];
double y1 = path[pathSize-1];
for(int i = 0; i < pathSize; i += 2) {
double x2 = path[i];
double y2 = path[i+1];
double xx0 = x1 - x0;
double yy0 = y1 - y0;
double xx1 = y1 - y2;
double yy1 = x2 - x1;
double dot = xx0*xx1 + yy0*yy1;
double ll2 = (xx0*xx0 + yy0*yy0)*(xx1*xx1 + yy1*yy1);
double s2 = dot*dot/ll2;
if (s2 > HELI_PRECISION_SQR) {
int dd = dot > 0.0 ? 1 : -1;
if (!d) d = dd; else
if (d != dd) { convex = FALSE; break; }
x0 = x1; y0 = y1;
x1 = x2; y1 = y2;
}
}
if (convex) { fill = FALSE; fillSimple = TRUE; }
}
// draw
int isPoint = FALSE;
double px, py;
if (pathSize >= 4) {
if (pathSize >= 6 && (fillSimple || fill)) {
HeliDrawingState *s = heliDrawingGetState();
int antialiasing = s->antialiasing && (!stroke || !isStrokeSolid(s, NULL));
if (fillSimple) drawFillSimple(antialiasing);
else drawFill(antialiasing);
}
if (stroke) drawStroke(close);
} else
if (origPathSize >= 4 && stroke) {
px = path[0];
py = path[1];
isPoint = TRUE;
}
resetPath();
if (isPoint) point(px, py);
}
void closePath()
{ endPath(TRUE, TRUE, TRUE, FALSE); }
void strokePath()
{ endPath(FALSE, TRUE, FALSE, FALSE); }
void lineTo(double x, double y)
{ pushPathPoint(x, y); }
void moveTo(double x, double y)
{ resetPath(); lineTo(x, y); }
HeliDrawingState *heliDrawingGetState()
{ return statesStack + statesStackIndex; }
HeliDrawingState *heliDrawingGetStateStack()
{ return statesStack; }
void resetState()
{ resetStateEx(STATE_ALL); }
void resetStateEx(unsigned int flags) {
if (flags & STATE_FILL_COLOR ) fill(COLOR_WHITE);
if (flags & STATE_FILL_TEXTURE ) noFillTexture();
if (flags & STATE_STROKE_COLOR ) stroke(COLOR_BLACK);
if (flags & STATE_STROKE_TEXTURE ) noStrokeTexture();
if (flags & STATE_STROKE_WIDTH ) strokeWidth(1);
if (flags & STATE_TEXT_ALIGN ) textAlign(HALIGN_LEFT, VALIGN_TOP);
if (flags & STATE_TEXT_SIZE ) textSize(24);
if (flags & STATE_TEXT_FONT ) textFontDefault();
if (flags & STATE_TARGET_FRAMEBUFFER) targetEx(NULL, FALSE, FALSE);
if (flags & STATE_TARGET_VIEWPORT ) viewportByWindow();
if (flags & STATE_TARGET_PROJECTION ) projectionByViewport();
if (flags & STATE_BACKGROUND ) background(COLOR_WHITE);
if (flags & STATE_TRANSFORM ) noTransform();
if (flags & STATE_CLIP ) noClip();
if (flags & STATE_ANTIALIASING ) enableAntialiasing();
}
void saveState()
{ saveStateEx(STATE_ALL); }
void saveStateEx(unsigned int flags) {
if (statesStackIndex >= sizeof(statesStack)/sizeof(*statesStack) - 1) {
fprintf(stderr, "helianthus: drawing stack overflow\n");
return;
}
++statesStackIndex;
memcpy(statesStack + statesStackIndex, statesStack + statesStackIndex - 1, sizeof(*statesStack));
statesStack[statesStackIndex].flags = flags;
heliGLGetCommonState(&statesStack[statesStackIndex].glState, flags);
}
void restoreState() {
assert(statesStackIndex > 0);
if (statesStackIndex <= 0) {
fprintf(stderr, "helianthus: drawing stack underflow\n");
return;
}
HeliDrawingState *prev = &statesStack[statesStackIndex];
heliGLSetCommonState(&prev->glState);
--statesStackIndex;
HeliDrawingState *curr = &statesStack[statesStackIndex];
unsigned int flags = ~prev->flags;
if (flags & STATE_FILL_COLOR)
memcpy(curr->fillColor, prev->fillColor, sizeof(curr->fillColor));
if (flags & STATE_FILL_TEXTURE)
memcpy(&curr->fillTexture, &prev->fillTexture, sizeof(curr->fillTexture));
if (flags & STATE_STROKE_COLOR)
memcpy(curr->strokeColor, prev->strokeColor, sizeof(curr->strokeColor));
if (flags & STATE_STROKE_TEXTURE)
memcpy(&curr->strokeTexture, &prev->strokeTexture, sizeof(curr->strokeTexture));
if (flags & STATE_STROKE_WIDTH)
curr->strokeWidth = prev->strokeWidth;
if (flags & STATE_TEXT_ALIGN)
{ curr->horAlign = prev->horAlign; curr->vertAlign = prev->vertAlign; }
if (flags & STATE_TEXT_SIZE)
curr->fontSize = prev->fontSize;
if (flags & STATE_TEXT_FONT)
curr->font = prev->font;
if (flags & STATE_ANTIALIASING)
curr->antialiasing = prev->antialiasing;
}
void heliDrawingClearFrame() {
unsigned int prev;
glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, (int*)&prev);
clear();
if (heliGLBindFramebufferPtr) heliGLBindFramebufferPtr(GL_DRAW_FRAMEBUFFER, prev);
}
void heliDrawingPrepareFrame() {
resetPath();
heliDrawingClearFrame();
glDisable(GL_DEPTH_TEST);
glDisable(GL_STENCIL_TEST);
glDisable(GL_CULL_FACE);
glDisable(GL_MULTISAMPLE);
glEnable(GL_BLEND);
if (heliGLBlendFuncSeparatePtr)
heliGLBlendFuncSeparatePtr(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE_MINUS_DST_ALPHA, GL_ONE);
else
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glEnable(GL_LINE_SMOOTH);
glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);
}
void heliDrawingFinish() {
resetPath();
free(path);
path = NULL;
pathAllocated = 0;
heliArrayDestroy(&heliDrawingFramebuffersToFlush);
}