openspades/Sources/Draw/GLLongSpriteRenderer.cpp

/*
 Copyright (c) 2013 yvt
 
 This file is part of OpenSpades.
 
 OpenSpades 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.
 
 OpenSpades 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 OpenSpades.  If not, see <http://www.gnu.org/licenses/>.
 
 */

#include "GLLongSpriteRenderer.h"
#include "GLRenderer.h"
#include "IGLDevice.h"
#include "../Core/Debug.h"
#include "GLProgram.h"
#include "GLImage.h"

namespace spades {
	namespace draw {
		
		GLLongSpriteRenderer::GLLongSpriteRenderer(GLRenderer *renderer):
		renderer(renderer), device(renderer->GetGLDevice()),
		projectionViewMatrix("projectionViewMatrix"),
		rightVector("rightVector"),
		upVector("upVector"),
		positionAttribute("positionAttribute"),
		texCoordAttribute("texCoordAttribute"),
		colorAttribute("colorAttribute"),
		texture("texture"),
		viewMatrix("viewMatrix"),
		fogDistance("fogDistance"),
		fogColor("fogColor")
		{
			SPADES_MARK_FUNCTION();
			
			program = renderer->RegisterProgram("Shaders/LongSprite.program");
		}
		
		GLLongSpriteRenderer::~GLLongSpriteRenderer(){
			SPADES_MARK_FUNCTION();
			
		}
		
		void GLLongSpriteRenderer::Add(spades::draw::GLImage *img,
								   spades::Vector3 p1,spades::Vector3 p2, float rad,
								   Vector4 color){
			SPADES_MARK_FUNCTION_DEBUG();
			Sprite spr;
			spr.image = img;
			spr.start = p1;
			spr.end = p2;
			spr.radius = rad;
			spr.color = color;
			sprites.push_back(spr);
		}
		
		void GLLongSpriteRenderer::Clear(){
			SPADES_MARK_FUNCTION();
			sprites.clear();
		}
		
		void GLLongSpriteRenderer::Render() {
			SPADES_MARK_FUNCTION();
			lastImage = NULL;
			program->Use();
			
			projectionViewMatrix(program);
			rightVector(program);
			upVector(program);
			texture(program);
			viewMatrix(program);
			fogDistance(program);
			fogColor(program);
			
			positionAttribute(program);
			texCoordAttribute(program);
			colorAttribute(program);
			
			projectionViewMatrix.SetValue(renderer->GetProjectionViewMatrix());
			viewMatrix.SetValue(renderer->GetViewMatrix());
			
			fogDistance.SetValue(renderer->GetFogDistance());
			
			Vector3 fogCol = renderer->GetFogColor();
			fogColor.SetValue(fogCol.x,fogCol.y,fogCol.z);
			
			const client::SceneDefinition& def = renderer->GetSceneDef();
			rightVector.SetValue(def.viewAxis[0].x,
								 def.viewAxis[0].y,
								 def.viewAxis[0].z);
			upVector.SetValue(def.viewAxis[1].x,
							  def.viewAxis[1].y,
							  def.viewAxis[1].z);
			texture.SetValue(0);
			
			device->ActiveTexture(0);
			
			device->EnableVertexAttribArray(positionAttribute(), true);
			device->EnableVertexAttribArray(texCoordAttribute(), true);
			device->EnableVertexAttribArray(colorAttribute(), true);
			
			
			for(size_t i = 0; i < sprites.size(); i++){
				Sprite& spr = sprites[i];
				if(spr.image != lastImage){
					Flush();
					lastImage = spr.image;
					SPAssert(vertices.empty());
				}
				
				Vertex v;
				v.r = spr.color.x;
				v.g = spr.color.y;
				v.b = spr.color.z;
				v.a = spr.color.w;
				
				uint32_t idx = (uint32_t)vertices.size();
				
				// clip by view plane
				{
					float d1 = Vector3::Dot(spr.start - def.viewOrigin,
											def.viewAxis[2]);
					float d2 = Vector3::Dot(spr.end - def.viewOrigin,
											def.viewAxis[2]);
					const float clipPlane = .1f;
					if(d1 < clipPlane && d2 < clipPlane)
						continue;
					if(d1 > clipPlane || d2 > clipPlane) {
						if(d1 < clipPlane){
							float per = (clipPlane - d1) / (d2 - d1);
							spr.start = Mix(spr.start, spr.end, per);
						}else if(d2 < clipPlane){
							float per = (clipPlane - d1) / (d2 - d1);
							spr.end = Mix(spr.start, spr.end, per);
						}
					}
				}
				
				// calculate view position
				Vector3 view1 = spr.start - def.viewOrigin;
				Vector3 view2 = spr.end - def.viewOrigin;
				view1 = MakeVector3(Vector3::Dot(view1, def.viewAxis[0]),
									Vector3::Dot(view1, def.viewAxis[1]),
									Vector3::Dot(view1, def.viewAxis[2]));
				view2 = MakeVector3(Vector3::Dot(view2, def.viewAxis[0]),
									Vector3::Dot(view2, def.viewAxis[1]),
									Vector3::Dot(view2, def.viewAxis[2]));
				
				// transform to screen
				Vector2 scr1 = MakeVector2(view1.x / view1.z,
										   view1.y / view1.z);
				Vector2 scr2 = MakeVector2(view2.x / view2.z,
										   view2.y / view2.z);
				
				Vector3 vecX = def.viewAxis[0] * spr.radius;
				Vector3 vecY = def.viewAxis[1] * spr.radius;
				float normalThreshold = spr.radius / ((view1.z + view2.z) * .5f);
				if((scr2 - scr1).GetPoweredLength() < normalThreshold) {
					// too short in screen; normal sprite
					v = spr.start - vecX - vecY;
					v.u = 0; v.v = 0;
					vertices.push_back(v);
					
					v = spr.start + vecX - vecY;
					v.u = 1; v.v = 0;
					vertices.push_back(v);
					
					v = spr.start - vecX + vecY;
					v.u = 0; v.v = 1;
					vertices.push_back(v);
					
					v = spr.start + vecX + vecY;
					v.u = 1; v.v = 1;
					vertices.push_back(v);
					
					indices.push_back(idx);
					indices.push_back(idx + 1);
					indices.push_back(idx + 2);
					indices.push_back(idx + 1);
					indices.push_back(idx + 3);
					indices.push_back(idx + 2);
				}else{
					Vector2 scrDir = (scr2 - scr1).Normalize();
					Vector2 normDir = {scrDir.y, -scrDir.x};
					Vector3 vecU = vecX * normDir.x + vecY * normDir.y;
					Vector3 vecV = vecX * scrDir.x  + vecY * scrDir.y;
					
					v = spr.start - vecU - vecV;
					v.u = 0; v.v = 0;
					vertices.push_back(v);
					
					v = spr.start + vecU - vecV;
					v.u = 1; v.v = 0;
					vertices.push_back(v);
					
					v = spr.start - vecU;
					v.u = 0; v.v = 0.5f;
					vertices.push_back(v);
					
					v = spr.start + vecU;
					v.u = 1; v.v = 0.5f;
					vertices.push_back(v);
					
					v = spr.end - vecU;
					v.u = 0; v.v = 0.5f;
					vertices.push_back(v);
					
					v = spr.end + vecU;
					v.u = 1; v.v = 0.5f;
					vertices.push_back(v);
					
					v = spr.end - vecU + vecV;
					v.u = 0; v.v = 1;
					vertices.push_back(v);
					
					v = spr.end + vecU + vecV;
					v.u = 1; v.v = 1;
					vertices.push_back(v);
					
					indices.push_back(idx);
					indices.push_back(idx + 1);
					indices.push_back(idx + 2);
					indices.push_back(idx + 1);
					indices.push_back(idx + 3);
					indices.push_back(idx + 2);
					
					indices.push_back(idx+2);
					indices.push_back(idx+2 + 1);
					indices.push_back(idx+2 + 2);
					indices.push_back(idx+2 + 1);
					indices.push_back(idx+2 + 3);
					indices.push_back(idx+2 + 2);
					
					indices.push_back(idx+4);
					indices.push_back(idx+4 + 1);
					indices.push_back(idx+4 + 2);
					indices.push_back(idx+4 + 1);
					indices.push_back(idx+4 + 3);
					indices.push_back(idx+4 + 2);
					
					idx = (uint32_t)vertices.size();
					
					v = spr.start - vecU + vecV;
					v.u = 0; v.v = 0;
					vertices.push_back(v);
					
					v = spr.start + vecU + vecV;
					v.u = 1; v.v = 0;
					vertices.push_back(v);
					
					v = spr.end - vecU - vecV;
					v.u = 0; v.v = 1;
					vertices.push_back(v);
					
					v = spr.end + vecU - vecV;
					v.u = 1; v.v = 1;
					vertices.push_back(v);
					
					v.r = v.g = v.b = v.a = 0.f;
					
					v = spr.start - vecU;
					v.u = 0; v.v = 0.5f;
					vertices.push_back(v);
					
					v = spr.start + vecU;
					v.u = 1; v.v = 0.5f;
					vertices.push_back(v);
					
					v = spr.end - vecU;
					v.u = 0; v.v = 0.5f;
					vertices.push_back(v);
					
					v = spr.end + vecU;
					v.u = 1; v.v = 0.5f;
					vertices.push_back(v);
					
					indices.push_back(idx);
					indices.push_back(idx + 1);
					indices.push_back(idx+2 + 2);
					indices.push_back(idx + 1);
					indices.push_back(idx+2 + 3);
					indices.push_back(idx+2 + 2);
					
					indices.push_back(idx+2);
					indices.push_back(idx+2 + 1);
					indices.push_back(idx+4 + 2);
					indices.push_back(idx+2 + 1);
					indices.push_back(idx+4 + 3);
					indices.push_back(idx+4 + 2);
					
				}
				
			}
			
			Flush();
			
			device->EnableVertexAttribArray(positionAttribute(), false);
			device->EnableVertexAttribArray(texCoordAttribute(), false);
			device->EnableVertexAttribArray(colorAttribute(), false);
		}
		
		void GLLongSpriteRenderer::Flush() {
			SPADES_MARK_FUNCTION_DEBUG();
			
			if(vertices.empty())
				return;
			
			device->VertexAttribPointer(positionAttribute(),
										3, IGLDevice::FloatType,
										false, sizeof(Vertex),
										&(vertices[0].x));
			device->VertexAttribPointer(texCoordAttribute(),
										2, IGLDevice::FloatType,
										false, sizeof(Vertex),
										&(vertices[0].u));
			device->VertexAttribPointer(colorAttribute(),
										4, IGLDevice::FloatType,
										false, sizeof(Vertex),
										&(vertices[0].r));
			
			SPAssert(lastImage);
			lastImage->Bind(IGLDevice::Texture2D);
			
			device->DrawElements(IGLDevice::Triangles,
								 indices.size(),
								 IGLDevice::UnsignedInt,
								 indices.data());
			
			vertices.clear();
			indices.clear();
		}
	}
}