/*
===========================================================================
Copyright (C) 2024 Gian 'myT' Schellenbaum

This file is part of Challenge Quake 3 (CNQ3).

Challenge Quake 3 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.

Challenge Quake 3 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 Challenge Quake 3. If not, see <https://www.gnu.org/licenses/>.
===========================================================================
*/
// Cinematic Rendering Pipeline - sunlight editor


#include "crp_local.h"
#include "../client/cl_imgui.h"
#include "compshaders/crp/fullscreen.h"
#include "compshaders/crp/sun_overlay.h"


#pragma pack(push, 4)
struct SunOverlayRC
{
	vec3_t direction;
	float angle;
	vec3_t color;
	float padding;
	float textureWidth;
	float textureHeight;
};
#pragma pack(pop)


static bool LoadSunFile(const char* filePath)
{
	bool success = false;
	void* data = NULL;
	if(ri.FS_ReadFile(filePath, &data) == sizeof(crp.sunlightData) &&
		data != NULL)
	{
		memcpy(&crp.sunlightData, data, sizeof(crp.sunlightData));
		success = true;
	}
	if(data != NULL)
	{
		ri.FS_FreeFile(data);
	}

	return success;
}

static void SaveSunFile(const char* filePath)
{
	FS_EnableCNQ3FolderWrites(qtrue);
	ri.FS_WriteFile(filePath, &crp.sunlightData, sizeof(crp.sunlightData));
	FS_EnableCNQ3FolderWrites(qfalse);
}

static void LoadSunFromShader(const shader_t* skyShader)
{
	vec2_t angles;
	angles[0] = DEG2RAD(skyShader->sunAzimuth);
	angles[1] = DEG2RAD(skyShader->sunInclination);
	VectorCopy(skyShader->sunColor, crp.sunlightData.color);
	crp.sunlightData.intensity = 1.0f;
	AzimuthInclinationToDirection(crp.sunlightData.direction, angles);
}

void DirectionToAzimuthInclination(float* sc, const float* dir)
{
	// 0=azimuth/phi, 1=inclination/theta
	sc[0] = atan2f(dir[1], dir[0]);
	sc[1] = atan2f(sqrtf(dir[0] * dir[0] + dir[1] * dir[1]), dir[2]);
}

void AzimuthInclinationToDirection(float* dir, const float* sc)
{
	// 0=azimuth/phi, 1=inclination/theta
	dir[0] = sinf(sc[1]) * cosf(sc[0]);
	dir[1] = sinf(sc[1]) * sinf(sc[0]);
	dir[2] = cosf(sc[1]);
}


void SunlightEditor::Init()
{
	{
		GraphicsPipelineDesc desc("G-Buffer Depth");
		MakeFullScreenPipeline(desc, ShaderByteCode(g_sun_overlay_ps));
		desc.AddRenderTarget(GLS_SRCBLEND_SRC_ALPHA | GLS_DSTBLEND_ONE_MINUS_SRC_ALPHA, crp.renderTargetFormat);
		pipeline = CreateGraphicsPipeline(desc);
	}
}

void SunlightEditor::ProcessWorld(world_t& world)
{
	skyShader = NULL;
	for(int i = 0; i < tr.numShaders; i++)
	{
		if(tr.shaders[i]->isSunDataValid)
		{
			skyShader = tr.shaders[i];
			break;
		}
	}

	if(!LoadSunFile(va("sun/%s.sun", world.baseName)) &&
		skyShader != NULL)
	{
		LoadSunFromShader(skyShader);
	}
}

void SunlightEditor::DrawOverlay()
{
	if(!drawOverlay || !IsViewportFullscreen(backEnd.viewParms))
	{
		return;
	}

	srp.renderMode = RenderMode::None;

	SCOPED_RENDER_PASS("Sun Overlay", 1.0f, 1.0f, 1.0f);

	CmdSetViewportAndScissor(0, 0, glConfig.vidWidth, glConfig.vidHeight);

	CmdBeginBarrier();
	CmdTextureBarrier(crp.renderTarget, ResourceStates::RenderTargetBit);
	CmdEndBarrier();

	SunOverlayRC rc = {};
	rc.angle = 0.0f;
	VectorCopy(crp.sunlightData.color, rc.color);
	VectorCopy(crp.sunlightData.direction, rc.direction);
	rc.textureWidth = glConfig.vidWidth;
	rc.textureHeight = glConfig.vidHeight;

	CmdBindRenderTargets(1, &crp.renderTarget, NULL);
	CmdBindPipeline(pipeline);
	CmdSetGraphicsRootConstants(0, sizeof(rc), &rc);
	CmdDraw(3, 0);
}

void SunlightEditor::DrawGUI()
{
	if(tr.world == NULL)
	{
		return;
	}

	GUI_AddMainMenuItem(GUI_MainMenu::Tools, "Edit Sunlight", "", &windowActive);

	if(!windowActive)
	{
		return;
	}

	if(ImGui::Begin("Sunlight", &windowActive, ImGuiWindowFlags_AlwaysAutoResize))
	{
		ImGui::Checkbox("Draw Sun", &drawOverlay);

		float angles[2];
		DirectionToAzimuthInclination(angles, crp.sunlightData.direction);
		ImGui::NewLine();
		ImGui::SliderAngle("Azimuth", &angles[0], 0.0f, 360.0f);
		ImGui::SliderAngle("Inclination", &angles[1], 0.0f, 180.0f);
		AzimuthInclinationToDirection(crp.sunlightData.direction, angles);
		ImGui::ColorEdit3("Color", crp.sunlightData.color);
		ImGui::SliderFloat("Light intensity", &crp.sunlightData.intensity, 0.0f, 10.0f);

		ImGui::NewLine();
		if(ImGui::Button("Save Config..."))
		{
			OpenSaveFileDialog("sun", ".sun");
		}
		ImGui::SameLine();
		if(ImGui::Button("Open Config..."))
		{
			OpenOpenFileDialog("sun", ".sun");
		}
		if(skyShader != NULL)
		{
			ImGui::SameLine();
			if(ImGui::Button("Import from Sky Shader"))
			{
				LoadSunFromShader(skyShader);
			}
		}

		if(SaveFileDialog())
		{
			SaveSunFile(GetSaveFileDialogPath());
		}

		if(OpenFileDialog())
		{
			LoadSunFile(GetOpenFileDialogPath());
		}
	}
	ImGui::End();
}