/*
* Part of LaGUI demonstration programs
* Copyright (C) 2022-2023 Wu Yiming
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/

#define NANOVG_GL3_IMPLEMENTATION

#include "la_5.h"
extern LA MAIN;
extern tnsMain* T;

void MyPanel(laUiList *uil, laPropPack *This, laPropPack *DetachedProps, laColumn *UNUSED, int context){
    laColumn* c=laFirstColumn(uil);
    laShowCanvas(uil,c,0,"tns","my_nanovg_canvas",-1);
}

typedef struct MyCanvas{
    laCanvasExtra e;
    NVGcontext* c;
}MyCanvas;

/* From NanoVG */
void drawColorwheel(NVGcontext* vg, float x, float y, float w, float h, float t)
{
	int i;
	float r0, r1, ax,ay, bx,by, cx,cy, aeps, r;
	float hue = sinf(t * 0.12f);
	NVGpaint paint;

	nvgSave(vg);

/*	nvgBeginPath(vg);
	nvgRect(vg, x,y,w,h);
	nvgFillColor(vg, nvgRGBA(255,0,0,128));
	nvgFill(vg);*/

	cx = x + w*0.5f;
	cy = y + h*0.5f;
	r1 = (w < h ? w : h) * 0.5f - 5.0f;
	r0 = r1 - 20.0f;
	aeps = 0.5f / r1;	// half a pixel arc length in radians (2pi cancels out).

	for (i = 0; i < 6; i++) {
		float a0 = (float)i / 6.0f * NVG_PI * 2.0f - aeps;
		float a1 = (float)(i+1.0f) / 6.0f * NVG_PI * 2.0f + aeps;
		nvgBeginPath(vg);
		nvgArc(vg, cx,cy, r0, a0, a1, NVG_CW);
		nvgArc(vg, cx,cy, r1, a1, a0, NVG_CCW);
		nvgClosePath(vg);
		ax = cx + cosf(a0) * (r0+r1)*0.5f;
		ay = cy + sinf(a0) * (r0+r1)*0.5f;
		bx = cx + cosf(a1) * (r0+r1)*0.5f;
		by = cy + sinf(a1) * (r0+r1)*0.5f;
		paint = nvgLinearGradient(vg, ax,ay, bx,by, nvgHSLA(a0/(NVG_PI*2),1.0f,0.55f,255), nvgHSLA(a1/(NVG_PI*2),1.0f,0.55f,255));
		nvgFillPaint(vg, paint);
		nvgFill(vg);
	}

	nvgBeginPath(vg);
	nvgCircle(vg, cx,cy, r0-0.5f);
	nvgCircle(vg, cx,cy, r1+0.5f);
	nvgStrokeColor(vg, nvgRGBA(0,0,0,64));
	nvgStrokeWidth(vg, 1.0f);
	nvgStroke(vg);

	// Selector
	nvgSave(vg);
	nvgTranslate(vg, cx,cy);
	nvgRotate(vg, hue*NVG_PI*2);

	// Marker on
	nvgStrokeWidth(vg, 2.0f);
	nvgBeginPath(vg);
	nvgRect(vg, r0-1,-3,r1-r0+2,6);
	nvgStrokeColor(vg, nvgRGBA(255,255,255,192));
	nvgStroke(vg);

	paint = nvgBoxGradient(vg, r0-3,-5,r1-r0+6,10, 2,4, nvgRGBA(0,0,0,128), nvgRGBA(0,0,0,0));
	nvgBeginPath(vg);
	nvgRect(vg, r0-2-10,-4-10,r1-r0+4+20,8+20);
	nvgRect(vg, r0-2,-4,r1-r0+4,8);
	nvgPathWinding(vg, NVG_HOLE);
	nvgFillPaint(vg, paint);
	nvgFill(vg);

	// Center triangle
	r = r0 - 6;
	ax = cosf(120.0f/180.0f*NVG_PI) * r;
	ay = sinf(120.0f/180.0f*NVG_PI) * r;
	bx = cosf(-120.0f/180.0f*NVG_PI) * r;
	by = sinf(-120.0f/180.0f*NVG_PI) * r;
	nvgBeginPath(vg);
	nvgMoveTo(vg, r,0);
	nvgLineTo(vg, ax,ay);
	nvgLineTo(vg, bx,by);
	nvgClosePath(vg);
	paint = nvgLinearGradient(vg, r,0, ax,ay, nvgHSLA(hue,1.0f,0.5f,255), nvgRGBA(255,255,255,255));
	nvgFillPaint(vg, paint);
	nvgFill(vg);
	paint = nvgLinearGradient(vg, (r+ax)*0.5f,(0+ay)*0.5f, bx,by, nvgRGBA(0,0,0,0), nvgRGBA(0,0,0,255));
	nvgFillPaint(vg, paint);
	nvgFill(vg);
	nvgStrokeColor(vg, nvgRGBA(0,0,0,64));
	nvgStroke(vg);

	// Select circle on triangle
	ax = cosf(120.0f/180.0f*NVG_PI) * r*0.3f;
	ay = sinf(120.0f/180.0f*NVG_PI) * r*0.4f;
	nvgStrokeWidth(vg, 2.0f);
	nvgBeginPath(vg);
	nvgCircle(vg, ax,ay,5);
	nvgStrokeColor(vg, nvgRGBA(255,255,255,192));
	nvgStroke(vg);

	paint = nvgRadialGradient(vg, ax,ay, 7,9, nvgRGBA(0,0,0,64), nvgRGBA(0,0,0,0));
	nvgBeginPath(vg);
	nvgRect(vg, ax-20,ay-20,40,40);
	nvgCircle(vg, ax,ay,7);
	nvgPathWinding(vg, NVG_HOLE);
	nvgFillPaint(vg, paint);
	nvgFill(vg);

	nvgRestore(vg);

	nvgRestore(vg);
}


void my_CanvasInit(laUiItem *ui){
    MyCanvas* mye=memAcquire(sizeof(MyCanvas)); ui->Extra=mye;
    la_CanvasInit(ui);
    mye->c=nvgCreateGL3(NVG_STENCIL_STROKES|NVG_DEBUG|NVG_ANTIALIAS);
}
void my_CanvasDestroy(laUiItem *ui){
    MyCanvas* mye=ui->Extra;
    nvgDeleteGL3(mye->c);
    la_CanvasDestroy(ui);
}

void my_CanvasDrawCanvas(laBoxedTheme *bt, void *unused_c, laUiItem* ui){
    laCanvasExtra* e=ui->Extra; MyCanvas* mye=e;
    int W, H; W = ui->R - ui->L; H = ui->B - ui->U;
    tnsFlush();

    if (!e->OffScr || e->OffScr->pColor[0]->Height != ui->B - ui->U || e->OffScr->pColor[0]->Width != ui->R - ui->L){
        if (e->OffScr) tnsDelete2DOffscreen(e->OffScr);
        e->OffScr = tnsCreate2DOffscreen(GL_RGBA8, W, H, 0, 0, 1);
    }

    tnsDrawToOffscreen(e->OffScr,1,0);
    tnsViewportWithScissor(0, 0, W, H);
    tnsResetViewMatrix();tnsResetModelMatrix();tnsResetProjectionMatrix();
    tnsOrtho(e->PanX - W * e->ZoomX / 2, e->PanX + W * e->ZoomX / 2, e->PanY - e->ZoomY * H / 2, e->PanY + e->ZoomY * H / 2, 100, -100);
    tnsClearColor(0,0,0,1); tnsClearAll();

    NVGcontext* vg=mye->c;

    nvgBeginFrame(vg,W,H,1);
    
    drawColorwheel(vg,0,0,W,H,1);

    nvgEndFrame(vg);
    tnsRestoreFromNanoVG();
}
void my_CanvasDrawOverlay(laUiItem* ui,int h){
    laCanvasExtra *e = ui->Extra;
    laBoxedTheme *bt = (*ui->Type->Theme);

    tnsUseImmShader(); tnsEnableShaderv(T->immShader);
    tnsUniformColorMode(T->immShader,0); tnsUniformOutputColorSpace(T->immShader, 0);

    tnsDraw2DTextureDirectly(e->OffScr->pColor[0], ui->L, ui->U, ui->R - ui->L, ui->B - ui->U);
    tnsFlush();

    la_CanvasDefaultOverlay(ui, h);
}


int main(int argc, char *argv[]){
    laGetReady();

    transSetLanguage("zh-CN");

    laCanvasTemplate* ct=laRegisterCanvasTemplate("my_nanovg_canvas", 0, 0, my_CanvasDrawCanvas, my_CanvasDrawOverlay, my_CanvasInit, my_CanvasDestroy);
 
    laRegisterUiTemplate("nanovg_panel","NanoVG Panel", MyPanel,0,0,"NanoVG Demonstration", 0,0,0);

    laWindow* w = laDesignWindow(-1,-1,600,600);
    laLayout* l = laDesignLayout(w,"My Layout");
    laCreatePanel(l->FirstBlock,"nanovg_panel");

    laStartWindow(w);
    laMainLoop();

    return 0;
}