[HGE]-源码分析-4 core里的demo和graphics（a）

    继续接着上次的，Core中的文件一个一个来。

顺便提一下demo，就是第一个cpp文件，上次说了这个是开场画面，想了下还是上代码一点一点说吧，随便提点怕说不清

ok，demo.cpp

他完成的事情是：把一进去那个logo画出来，停留一小会，然后滚蛋

 

 

/*** Haaf's Game Engine 1.8** Copyright (C) 2003-2007, Relish Games** hge.relishgames.com**** Core functions implementation: HGE splash screen*/#include "hge_impl.h"#ifdef DEMOhgeQuad dquad;//定义的一个区域数据结构，可以理解为一个方格，在这个方格里可以放我们想画的图片，画方格就行float dtime;//demo停留时间//这个很有意思，是把图片嵌入代码的方式，这是个位图，这样做的好处是它就包含在hge.dll里面，不用再配个图片跑的时候才载入了，想到于刻在了心里（=。=）//这是人家的logo当然要无时不刻都有了。unsigned short hgelogo[]={0x5089,0x474E,0x0A0D,0x0A1A,0x0000,0x0D00,0x4849,0x5244,0x0000,0x8000,0x0000,0x8000,0x0308,0x0000,0xF400,0x91E0,0x00F9,0x0000,0x6704,0x4D41,0x0041,0xAF00,0x37C8,0x8A05,0x00E9,0x0000,0x7419,0x5845,0x5374,0x666F,0x7774,0x7261,0x0065,0x6441,0x626F,0x2065,0x6D49,0x6761,0x5265,0x6165,0x7964,0xC971,0x3C65,0x0000,0x3000,0x4C50,0x4554,0x8F8F,0x298F,0x2929,0xFFFF,0xEEFF,0xEEEE,0xCECE,0xBACE,0xBABA,0x7575,0xAA75,0xAAAA,0x4444,0x5544,0x5555,0xF8F8,0xE0F8,0xE0E0,0x6565,0x1065,0x1010,0x0000,0xD600,0xD6D6,0x531D,0x9976,0x0000,0x3008,0x4449,0x5441,0xDA78,0xE062,0x601B,0x1000,0x0C40,0xED03,0x8000,0x1A00,0x0770,0x0400,0x80D0,0x003B,0x8020,0xDC06,0x0001,0x3401,0x0EE0,0x0800,0x01A0,0x0077,0x0040,0xB80D,0x0003,0x6802,0x1DC0,0x1000,0x0340,0x00EE,0x0080,0x701A,0x0007,0xD004,0x3B80,0x2000,0x9080,0xC01D,0xC3C8,0xCEC0,0xCACA,0xC2C2,0x334F,0xC2C0,0xCAC2,0xCECA,0xC3C0,0x6488,0x4029,0x2100,0xC01C,0xCEC1,0x3744,0xCEC0,0xB701,0x2016,0xE080,0x600E,0x6663,0x6262,0x6061,0xE4E3,0x60E0,0x21A4,0xE0E0,0x64E0,0x6063,0x6261,0x6662,0xD983,0x100B,0x3040,0x7007,0x3330,0x72B1,0x2BD2,0x39DE,0x9959,0x6198,0x0061,0x4010,0x0730,0x33B0,0xF2B1,0x2FD2,0xF1E5,0x32B2,0x43B1,0x0099,0x0401,0x0075,0x1323,0x2713,0xD33D,0x273E,0x1313,0x2534,0x0402,0xD410,0x3C01,0x2C4C,0xCDF4,0x2C7D,0x3C4C,0x0610,0x0040,0x1D41,0xC0C0,0xE744,0x0102,0x216E,0x0040,0xC031,0x0092,0x7D1B,0xC01D,0x4B06,0x0004,0x0401,0x0075,0x7D2B,0x0093,0x1128,0x42B0,0x0018,0x0401,0x0077,0x7D07,0xC01D,0x7301,0x4000,0x3100,0xD2C0,0x5904,0xE00E,0x1605,0xAC2B,0xC040,0xC6C0,0xB241,0xA003,0x1EA9,0x8020,0x0EE0,0x9440,0xACCF,0xC050,0x5483,0xC04B,0x90C4,0x714B,0x1E3E,0xA456,0x95D2,0x0199,0x8E45,0x0715,0x9B80,0x7308,0x4000,0x4100,0xC01D,0xE48F,0x9800,0x6C91,0xEEC8,0x0285,0x8F24,0xB232,0x97A0,0xC8F0,0x18E9,0x2D57,0x7080,0x3F00,0x0184,0x4010,0x3B64,0x0780,0xE98B,0xBC2C,0x3BA4,0x2000,0xC880,0x0075,0x560F,0x59E3,0x7748,0x4000,0x9100,0x00E9,0x6646,0xE6EC,0x9033,0x00EC,0x0080,0xD322,0xAC01,0x2CB8,0x2460,0x01D5,0x0100,0x9E44,0x1803,0x06E1,0x8372,0x379A,0x0C8C,0x4118,0xB440,0x0003,0x8802,0x073C,0xA030,0x3B27,0x9244,0x45E0,0x8435,0x0D95,0x6015,0x0038,0x8020,0x73C8,0x3300,0x887A,0x9C23,0x83C4,0x10D3,0x0014,0x0077,0x0040,0xE591,0x7800,0xB00C,0x1923,0x1A88,0x4407,0x003B,0x8020,0x72C8,0x0F00,0x779A,0x8041,0x161B,0x24E6,0x003A,0x8020,0x72C8,0x1B00,0x8296,0x9611,0x982F,0x7449,0x4000,0x9100,0x00E5,0xF476,0x8D34,0x089C,0x7448,0x4000,0x9100,0x00E5,0x2C56,0x600E,0xD323,0x0001,0x4401,0x0735,0xA0F0,0x77D6,0x3B44,0x2000,0xA880,0x00E6,0x4034,0x03B4,0x0200,0xC068,0x001D,0x4010,0x1C78,0xC0C0,0x0701,0x646C,0x003B,0x10C9,0x6020,0x74C4,0x4000,0xE100,0x0071,0x4036,0x03B2,0x0150,0xA62B,0x0003,0x6802,0x1DC0,0x1000,0x0340,0x00EE,0x0080,0x86A2,0xB003,0xB855,0x3B44,0x2000,0x0680,0x01DC,0x0100,0xE034,0x000E,0x2008,0x0E3C,0x6A40,0x304B,0xED90,0xD400,0x0906,0xA60F,0x0003,0x8802,0x051A,0x3E11,0x1007,0x882C,0x0200,0xC068,0x001D,0x4010,0x70D4,0xB800,0xE20E,0xD326,0x0001,0x3401,0xD5E0,0x4031,0x0D00,0x03B8,0x0200,0xC068,0x001D,0x4010,0x3994,0x9780,0x0772,0x0400,0x6510,0x426D,0xCA0E,0x001D,0x4010,0xB594,0x398A,0x5B31,0xA4C5,0x003A,0x8020,0xEB28,0x3017,0x0F20,0x91FC,0x00E7,0x0080,0xACA2,0xC467,0xD98D,0x2233,0x01D5,0x0100,0x6144,0x90DF,0x2303,0x9009,0x00EA,0x0080,0xB0A2,0xCC77,0x88CC,0x001E,0x3AA4,0x2000,0xC880,0x0073,0x6207,0x8C70,0x750D,0x007C,0x01DD,0x38DC,0xC947,0x0EA0,0x0800,0x6A20,0x908F,0x6FE0,0x600F,0xA019,0x0800,0x7220,0x88C7,0x8D30,0x6666,0xCB21,0x0001,0x4401,0x28EE,0x1B19,0xD186,0xAC6C,0x3964,0x2000,0xC880,0x271E,0x4064,0x879F,0x23E2,0x01CF,0x0100,0xFE44,0x2948,0xFA0F,0x2518,0x0E79,0x0800,0xF220,0x801D,0xF69C,0x93C1,0xE460,0x0039,0x8020,0x38B0,0x8480,0x72C1,0x361E,0xD650,0xE362,0x7D24,0x0BBE,0x00EE,0x0080,0xC8A2,0x1401,0xB800,0x0003,0x6802,0x1DC0,0x1000,0x0340,0x00EE,0x0080,0x701A,0x0007,0xD004,0x3B80,0x2000,0x0680,0x01DC,0x0100,0xE034,0x000E,0xA008,0x7701,0x4000,0x0D00,0x03B8,0x0200,0xEA08,0x2E00,0xBA26,0x2E03,0xCD88,0x0100,0xE034,0x000E,0xA008,0x7701,0x4000,0x0D00,0x03B8,0x0200,0x9088,0x4003,0x9D23,0xCC3C,0xCC4C,0xBC3C,0x1C7C,0x2C2C,0x0C1C,0x0140,0x2616,0x4E36,0xF026,0x29F8,0x900B,0x64E0,0x0261,0x1C51,0x2C0C,0x9510,0xB6A0,0x5801,0x9998,0x8D83,0x9B89,0x8183,0x0390,0x0200,0x6210,0x38E5,0xC000,0x0820,0x6D63,0x526D,0xFFFD,0x8B73,0x01F1,0x1C0E,0x2323,0x0630,0xEC48,0x25B8,0xAD87,0x3D80,0x09C8,0x73A1,0x9600,0x120F,0x025A,0x0E2B,0x2BEF,0x4E8A,0xDBB8,0xB914,0x00A6,0x005F,0xA031,0x34F5,0x1D30,0x6A00,0x0099,0x05AD,0x4635,0x8098,0x3016,0x1D02,0x6C00,0x8211,0x649B,0xC0AC,0x0846,0xB310,0xDB82,0x2022,0x0192,0x106C,0x0584,0x18A4,0x3918,0x4770,0x7401,0x056A,0x8020,0x7188,0x0F00,0xCC2F,0x1C01,0x4C8C,0x8C7C,0xDC1C,0x3720,0xB0F0,0x72B2,0x6C43,0x0162,0xC4DA,0xCACA,0x750C,0xD40D,0x9C01,0xAB40,0x1839,0x35F1,0xA1DF,0x000E,0x2008,0xD406,0x2729,0x0E2C,0x60E0,0x0704,0xD83C,0x6C01,0x2C7C,0x6C7C,0x208C,0xC00B,0x597A,0xAE81,0xB601,0x590D,0x0321,0x4845,0x800E,0xE174,0xB019,0xDEB5,0xD099,0x95FA,0x0100,0x80C4,0xB7D6,0x92C5,0x1806,0x9958,0x0E60,0xF200,0x80F8,0x05FE,0x17BA,0x051A,0x34A0,0x8DC0,0x37F0,0xC58C,0xCAC0,0xB208,0x8F9B,0x8F01,0xA003,0xDD13,0x0100,0x5F04,0x82C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//初始化操作没什么可说的，无非载入刚才那个图片，设定一下坐标void DInit() {int x=pHGE->System_GetState(HGE_SCREENWIDTH)/2;int y=pHGE->System_GetState(HGE_SCREENHEIGHT)/2;dquad.tex=pHGE->Texture_Load((char *)hgelogo, sizeof(hgelogo));dquad.blend=BLEND_DEFAULT;for(int i=0; i<4; i++) {dquad.v[i].z=0.5f;dquad.v[i].col=0xFFFFFFFF;}dquad.v[0].tx=0.0f; dquad.v[0].ty=0.0f;dquad.v[1].tx=1.0f; dquad.v[1].ty=0.0f;dquad.v[2].tx=1.0f; dquad.v[2].ty=1.0f;dquad.v[3].tx=0.0f; dquad.v[3].ty=1.0f;dquad.v[0].x=x-64.0f; dquad.v[0].y=y-64.0f;dquad.v[1].x=x+64.0f; dquad.v[1].y=y-64.0f;dquad.v[2].x=x+64.0f; dquad.v[2].y=y+64.0f;dquad.v[3].x=x-64.0f; dquad.v[3].y=y+64.0f;dtime=0.0f;}

//完成之后void DDone() {pHGE->Texture_Free(dquad.tex);}//由时间控制的帧bool DFrame() {BYTE alpha;DWORD col;dtime+=pHGE->Timer_GetDelta();if(dtime<0.25) alpha=(BYTE)((dtime*4)*0xFF);else if(dtime<1.0) alpha=0xFF;else if(dtime<1.25) alpha=(BYTE)((1.0f-(dtime-1.0f)*4)*0xFF);else return true;col=0xFFFFFF | (alpha<<24);dquad.v[0].col=col;dquad.v[1].col=col;dquad.v[2].col=col;dquad.v[3].col=col;pHGE->Gfx_BeginScene();pHGE->Gfx_Clear(0);pHGE->Gfx_RenderQuad(&dquad);pHGE->Gfx_EndScene();return false;}

很简单的一个小动画，它给我们的启发最大的就是那个嵌入的图片了，我们平时想做的话得先把图片输出出来，然后复制到自己的代码里，更具体的做法网上有，

但是不要改人家HGE的logo啊，而且在使用HGE或者其他什么引擎的时候，播放他们的logo是最起码的致敬。

demo里没什么可说的，因为它的实现也是调用的实现好的其他函数。

大头是graphics，它的实现没有从0开始那么复杂，很多都是建立在dx8接口上的，所以代码不是很多。

以下是graphics.cpp里所有函数的接口，在hge_impl.h里面

virtual boolCALLGfx_BeginScene(HTARGET target=0);virtual voidCALLGfx_EndScene();virtual voidCALLGfx_Clear(DWORD color);virtual voidCALLGfx_RenderLine(float x1, float y1, float x2, float y2, DWORD color=0xFFFFFFFF, float z=0.5f);virtual voidCALLGfx_RenderTriple(const hgeTriple *triple);virtual voidCALLGfx_RenderQuad(const hgeQuad *quad);virtual hgeVertex*CALLGfx_StartBatch(int prim_type, HTEXTURE tex, int blend, int *max_prim);virtual voidCALLGfx_FinishBatch(int nprim);virtual voidCALLGfx_SetClipping(int x=0, int y=0, int w=0, int h=0);virtual voidCALLGfx_SetTransform(float x=0, float y=0, float dx=0, float dy=0, float rot=0, float hscale=0, float vscale=0); virtual HTARGETCALLTarget_Create(int width, int height, bool zbuffer);virtual voidCALLTarget_Free(HTARGET target);virtual HTEXTURECALLTarget_GetTexture(HTARGET target);virtual HTEXTURECALLTexture_Create(int width, int height);virtual HTEXTURECALLTexture_Load(const char *filename, DWORD size=0, bool bMipmap=false);virtual voidCALLTexture_Free(HTEXTURE tex);virtual intCALLTexture_GetWidth(HTEXTURE tex, bool bOriginal=false);virtual intCALLTexture_GetHeight(HTEXTURE tex, bool bOriginal=false);virtual DWORD*CALLTexture_Lock(HTEXTURE tex, bool bReadOnly=true, int left=0, int top=0, int width=0, int height=0);virtual voidCALLTexture_Unlock(HTEXTURE tex);

HGE代码还是很规范的，命名什么的都很好理解，好的代码是木有注释的，因为它们自解释，大家要一起努力写自解释的代码呀~

函数一个一个过一遍吧，顺序按cpp里的说

代码里会有一些全局的变量，它们的定义都在hge_impl.h里面，而且名字也比较容易读，看的时候可以跟到定义看看它具体是什么

void CALL HGE_Impl::Gfx_Clear(DWORD color){if(pCurTarget){if(pCurTarget->pDepth)pD3DDevice->Clear( 0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, color, 1.0f, 0 );elsepD3DDevice->Clear( 0, NULL, D3DCLEAR_TARGET, color, 1.0f, 0 );}else{if(bZBuffer)pD3DDevice->Clear( 0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, color, 1.0f, 0 );elsepD3DDevice->Clear( 0, NULL, D3DCLEAR_TARGET, color, 1.0f, 0 );}}

清屏函数，在进行渲染前先把屏幕用一种指定颜色涂了=。=

里面分了很多种情况，首先是一个判断pCurTarget，引擎是用链表来管理要渲染的东西的，这里的pCurTarget就是当前含有的渲染目标

判断的目的是看是清目标表面还是目标表面和z缓存都清。（dx接口的东西查下directx_sdk.chm），还有更多原理性的东西比如离屏表面，页面切换这些

都不在这里详述（太多鸟），2D的原理比如光栅化算法，剪切等等推荐看《windows游戏编程大师技巧》，书灰常老但是一看就明白了，里面是讲

2d图形实现方法。

裁剪设置函数

void CALL HGE_Impl::Gfx_SetClipping(int x, int y, int w, int h){D3DVIEWPORT8 vp;//声明了一个D3D的视口，现在的D3D9里已经是D3DVIEWPORT9了，这是个结构体，里面是视口信息，坐标，宽高，深度范围         //最后的裁剪还要靠这个int scr_width, scr_height;//裁剪区域的宽高        //两种获取方式，要不是窗口的，要不是图片的if(!pCurTarget) {scr_width=pHGE->System_GetStateInt(HGE_SCREENWIDTH);scr_height=pHGE->System_GetStateInt(HGE_SCREENHEIGHT);}else {scr_width=Texture_GetWidth((HTEXTURE)pCurTarget->pTex);scr_height=Texture_GetHeight((HTEXTURE)pCurTarget->pTex);}if(!w) {vp.X=0;vp.Y=0;vp.Width=scr_width;vp.Height=scr_height;}else{if(x<0) { w+=x; x=0; }if(y<0) { h+=y; y=0; }if(x+w > scr_width) w=scr_width-x;if(y+h > scr_height) h=scr_height-y;vp.X=x;vp.Y=y;vp.Width=w;vp.Height=h;}vp.MinZ=0.0f;vp.MaxZ=1.0f;_render_batch();pD3DDevice->SetViewport(&vp);D3DXMATRIX tmp;D3DXMatrixScaling(&matProj, 1.0f, -1.0f, 1.0f);D3DXMatrixTranslation(&tmp, -0.5f, +0.5f, 0.0f);D3DXMatrixMultiply(&matProj, &matProj, &tmp);D3DXMatrixOrthoOffCenterLH(&tmp, (float)vp.X, (float)(vp.X+vp.Width), -((float)(vp.Y+vp.Height)), -((float)vp.Y), vp.MinZ, vp.MaxZ);D3DXMatrixMultiply(&matProj, &matProj, &tmp);pD3DDevice->SetTransform(D3DTS_PROJECTION, &matProj);}

这个函数重要的地方在于最后的这些矩阵运算，因为HGE是用3D来做2D的效果，所以流程和3D的差不多，也是要设置矩阵

这里是设置一个投影矩阵（就是咱们能看到的那一块，在这个范围里的会在程序工作区显示出来）

前面生成的那个vp视口就是用来设置投影矩阵的。

D3DXMatrixScaling创建一个缩放矩阵，这里生成了一个逆置Y坐标的矩阵

D3DXMatrixTranslation是生成位置变换矩阵，这里调的很小，就是一点点微调

D3DXMatrixMultiply是做矩阵乘，效果是把这两个矩阵效果叠加，也就是重新生成的矩阵就是既逆置Y坐标又可以进行位置微调

D3DXMatrixOrthoOffCenterLH  生成一个自定义正交投影矩阵（左手坐标系），这个就是我们的投影矩阵雏形，参数是最开始生成的那个视口，

也就是呈现在这个范围里的东西会被我们看见，裁剪的作用也就是把该留下的让我们看见，不该留下的看不见。

HGE裁剪的效果是利用投影矩阵进行一种“视觉”裁剪，只保留视口里的部分。

在windows游戏编程里有另一种裁剪方式，就是直接裁剪，因为里面是直接往离屏表面上画像素点，所以就判断区域位置然后直接画区域里面的部分。

这个函数的最后给投影矩阵微调，之后设定为投影矩阵，完成裁剪。