001    package net.minecraft.src;
002    
003    import cpw.mods.fml.common.Side;
004    import cpw.mods.fml.common.asm.SideOnly;
005    import java.nio.FloatBuffer;
006    import java.nio.IntBuffer;
007    import org.lwjgl.opengl.GL11;
008    import org.lwjgl.util.glu.GLU;
009    
010    @SideOnly(Side.CLIENT)
011    public class ActiveRenderInfo
012    {
013        /** The calculated view object X coordinate */
014        public static float objectX = 0.0F;
015    
016        /** The calculated view object Y coordinate */
017        public static float objectY = 0.0F;
018    
019        /** The calculated view object Z coordinate */
020        public static float objectZ = 0.0F;
021    
022        /** The current GL viewport */
023        private static IntBuffer viewport = GLAllocation.createDirectIntBuffer(16);
024    
025        /** The current GL modelview matrix */
026        private static FloatBuffer modelview = GLAllocation.createDirectFloatBuffer(16);
027    
028        /** The current GL projection matrix */
029        private static FloatBuffer projection = GLAllocation.createDirectFloatBuffer(16);
030    
031        /** The computed view object coordinates */
032        private static FloatBuffer objectCoords = GLAllocation.createDirectFloatBuffer(3);
033    
034        /** The X component of the entity's yaw rotation */
035        public static float rotationX;
036    
037        /** The combined X and Z components of the entity's pitch rotation */
038        public static float rotationXZ;
039    
040        /** The Z component of the entity's yaw rotation */
041        public static float rotationZ;
042    
043        /**
044         * The Y component (scaled along the Z axis) of the entity's pitch rotation
045         */
046        public static float rotationYZ;
047    
048        /**
049         * The Y component (scaled along the X axis) of the entity's pitch rotation
050         */
051        public static float rotationXY;
052    
053        /**
054         * Updates the current render info and camera location based on entity look angles and 1st/3rd person view mode
055         */
056        public static void updateRenderInfo(EntityPlayer par0EntityPlayer, boolean par1)
057        {
058            GL11.glGetFloat(GL11.GL_MODELVIEW_MATRIX, modelview);
059            GL11.glGetFloat(GL11.GL_PROJECTION_MATRIX, projection);
060            GL11.glGetInteger(GL11.GL_VIEWPORT, viewport);
061            float var2 = (float)((viewport.get(0) + viewport.get(2)) / 2);
062            float var3 = (float)((viewport.get(1) + viewport.get(3)) / 2);
063            GLU.gluUnProject(var2, var3, 0.0F, modelview, projection, viewport, objectCoords);
064            objectX = objectCoords.get(0);
065            objectY = objectCoords.get(1);
066            objectZ = objectCoords.get(2);
067            int var4 = par1 ? 1 : 0;
068            float var5 = par0EntityPlayer.rotationPitch;
069            float var6 = par0EntityPlayer.rotationYaw;
070            rotationX = MathHelper.cos(var6 * (float)Math.PI / 180.0F) * (float)(1 - var4 * 2);
071            rotationZ = MathHelper.sin(var6 * (float)Math.PI / 180.0F) * (float)(1 - var4 * 2);
072            rotationYZ = -rotationZ * MathHelper.sin(var5 * (float)Math.PI / 180.0F) * (float)(1 - var4 * 2);
073            rotationXY = rotationX * MathHelper.sin(var5 * (float)Math.PI / 180.0F) * (float)(1 - var4 * 2);
074            rotationXZ = MathHelper.cos(var5 * (float)Math.PI / 180.0F);
075        }
076    
077        /**
078         * Returns a vector representing the projection along the given entity's view for the given distance
079         */
080        public static Vec3 projectViewFromEntity(EntityLiving par0EntityLiving, double par1)
081        {
082            double var3 = par0EntityLiving.prevPosX + (par0EntityLiving.posX - par0EntityLiving.prevPosX) * par1;
083            double var5 = par0EntityLiving.prevPosY + (par0EntityLiving.posY - par0EntityLiving.prevPosY) * par1 + (double)par0EntityLiving.getEyeHeight();
084            double var7 = par0EntityLiving.prevPosZ + (par0EntityLiving.posZ - par0EntityLiving.prevPosZ) * par1;
085            double var9 = var3 + (double)(objectX * 1.0F);
086            double var11 = var5 + (double)(objectY * 1.0F);
087            double var13 = var7 + (double)(objectZ * 1.0F);
088            return par0EntityLiving.worldObj.func_82732_R().getVecFromPool(var9, var11, var13);
089        }
090    
091        /**
092         * Returns the block ID at the current camera location (either air or fluid), taking into account the height of
093         * fluid blocks
094         */
095        public static int getBlockIdAtEntityViewpoint(World par0World, EntityLiving par1EntityLiving, float par2)
096        {
097            Vec3 var3 = projectViewFromEntity(par1EntityLiving, (double)par2);
098            ChunkPosition var4 = new ChunkPosition(var3);
099            int var5 = par0World.getBlockId(var4.x, var4.y, var4.z);
100    
101            if (var5 != 0 && Block.blocksList[var5].blockMaterial.isLiquid())
102            {
103                float var6 = BlockFluid.getFluidHeightPercent(par0World.getBlockMetadata(var4.x, var4.y, var4.z)) - 0.11111111F;
104                float var7 = (float)(var4.y + 1) - var6;
105    
106                if (var3.yCoord >= (double)var7)
107                {
108                    var5 = par0World.getBlockId(var4.x, var4.y + 1, var4.z);
109                }
110            }
111    
112            return var5;
113        }
114    }