opengles之mipmap纹理
程序员文章站
2022-07-02 14:30:07
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为什么要用mipmap?
在三维世界中,显示一张图片的大小与摄像机的位置有关,近的地方，图片实际像素大一些，远 的地方，图片实际像素就小一些,比如一张64*64的图片
在近处, 显示出来可能是50*50,远处可能显示出来就是20*20。
mipmap纹理技术是目前解决纹理分辨率与视点距离关系的最有效途径,它会先将图片压缩成很多逐渐缩小的图片,例如一张64*64的图片,会产生64*64,32*32,16*16,8*8,4*4,2*2,1*1的7张图片,当屏幕上需要绘制像素点为20*20时,程序只是利用32*32和16*16 这两张图片来计算出即将显示为20*20大小的一个图片,这比单独利用32*32的哪张原始图片计算出来的图片效果好很多，速度也快。
效果图：(GL_LINEAR_MIPMAP_LINEAR过滤模式)
Mipmap过滤
Mipmap的纹理过滤模式如下表：
| 常量 | 描述 |
| GL_NEAREST | 在mip基层上使用最邻近过滤 |
| GL_LINEAR | 在mip基层上使用线性过滤 |
| GL_NEAREST_MIPMAP_NEAREST | 选择最邻近的mip层，并使用最邻近过滤 |
| GL_NEAREST_MIPMAP_LINEAR | 在mip层之间使用线性插值和最邻近过滤 |
| GL_LINEAR_MIPMAP_NEAREST | 选择最邻近的mip层，使用线性过滤 |
| GL_LINEAR_MIPMAP_LINEAR |
在mip层之间使用线性插值和使用线性过滤，又称三线性mipmap |
GL_NEAREST_MIPMAP_NEAREST 过滤模式：
shader实现类：
#pragma once
#include <assert.h>
class ShaderId
{
public:
ShaderId()
{
_shaderId = -1;
}
int _shaderId;
};
/**
* 程序
*/
class ProgramId
{
public:
int _programId;
ShaderId _vertex;
ShaderId _fragment;
public:
ProgramId()
{
_programId = -1;
}
public:
/**
* 加载函数
*/
bool createProgram(const char* vertex, const char* fragment)
{
bool error = false;
do
{
if (vertex)
{
_vertex._shaderId = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(_vertex._shaderId, 1, &vertex, 0);
glCompileShader(_vertex._shaderId);
GLint compileStatus;
glGetShaderiv(_vertex._shaderId, GL_COMPILE_STATUS, &compileStatus);
error = compileStatus == GL_FALSE;
if (error)
{
GLchar messages[256];
glGetShaderInfoLog(_vertex._shaderId, sizeof(messages), 0, messages);
assert(messages && 0 != 0);
break;
}
}
if (fragment)
{
_fragment._shaderId = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(_fragment._shaderId, 1, &fragment, 0);
glCompileShader(_fragment._shaderId);
GLint compileStatus;
glGetShaderiv(_fragment._shaderId, GL_COMPILE_STATUS, &compileStatus);
error = compileStatus == GL_FALSE;
if (error)
{
GLchar messages[256];
glGetShaderInfoLog(_fragment._shaderId, sizeof(messages), 0, messages);
assert(messages && 0 != 0);
break;
}
}
_programId = glCreateProgram();
if (_vertex._shaderId)
{
glAttachShader(_programId, _vertex._shaderId);
}
if (_fragment._shaderId)
{
glAttachShader(_programId, _fragment._shaderId);
}
glLinkProgram(_programId);
GLint linkStatus;
glGetProgramiv(_programId, GL_LINK_STATUS, &linkStatus);
if (linkStatus == GL_FALSE)
{
GLchar messages[256];
glGetProgramInfoLog(_programId, sizeof(messages), 0, messages);
break;
}
glUseProgram(_programId);
} while (false);
if (error)
{
if (_fragment._shaderId)
{
glDeleteShader(_fragment._shaderId);
_fragment._shaderId = 0;
}
if (_vertex._shaderId)
{
glDeleteShader(_vertex._shaderId);
_vertex._shaderId = 0;
}
if (_programId)
{
glDeleteProgram(_programId);
_programId = 0;
}
}
return true;
}
/**
* 使用程序
*/
virtual void begin()
{
glUseProgram(_programId);
}
/**
* 使用完成
*/
virtual void end()
{
glUseProgram(0);
}
};
class PROGRAM_P2_C4 :public ProgramId
{
public:
typedef int attribute;
typedef int uniform;
public:
attribute _position;
uniform _color;
uniform _MVP;
public:
PROGRAM_P2_C4()
{
_position = -1;
_color = -1;
_MVP = -1;
}
~PROGRAM_P2_C4()
{
}
/// 初始化函数
virtual bool initialize()
{
const char* vs =
{
"precision lowp float; "
"uniform mat4 _MVP;"
"attribute vec2 _position;"
"void main()"
"{"
" vec4 pos = vec4(_position,0,1);"
" gl_Position = _MVP * pos;"
"}"
};
const char* ps =
{
"precision lowp float; "
"uniform vec4 _color;"
"void main()"
"{"
" gl_FragColor = _color;"
"}"
};
bool res = createProgram(vs, ps);
if (res)
{
_position = glGetAttribLocation(_programId, "_position");
_color = glGetUniformLocation(_programId, "_color");
_MVP = glGetUniformLocation(_programId, "_MVP");
}
return res;
}
/**
* 使用程序
*/
virtual void begin()
{
glUseProgram(_programId);
glEnableVertexAttribArray(_position);
}
/**
* 使用完成
*/
virtual void end()
{
glDisableVertexAttribArray(_position);
glUseProgram(0);
}
};
class PROGRAM_P2_AC4 :public ProgramId
{
public:
typedef int attribute;
typedef int uniform;
public:
attribute _position;
attribute _color;
uniform _MVP;
public:
PROGRAM_P2_AC4()
{
_position = -1;
_color = -1;
_MVP = -1;
}
~PROGRAM_P2_AC4()
{
}
/// 初始化函数
virtual bool initialize()
{
const char* vs =
{
"precision lowp float; "
"uniform mat4 _MVP;"
"attribute vec2 _position;"
"attribute vec4 _color;"
"varying vec4 _outColor;"
"void main()"
"{"
" vec4 pos = vec4(_position,0,1);"
" _outColor = _color;"
" gl_Position = _MVP * pos;"
"}"
};
const char* ps =
{
"precision lowp float; "
"varying vec4 _outColor;"
"void main()"
"{"
" gl_FragColor = _outColor;"
"}"
};
bool res = createProgram(vs, ps);
if (res)
{
_position = glGetAttribLocation(_programId, "_position");
_color = glGetAttribLocation(_programId, "_color");
_MVP = glGetUniformLocation(_programId, "_MVP");
}
return res;
}
/**
* 使用程序
*/
virtual void begin()
{
glUseProgram(_programId);
glEnableVertexAttribArray(_position);
glEnableVertexAttribArray(_color);
}
/**
* 使用完成
*/
virtual void end()
{
glDisableVertexAttribArray(_position);
glDisableVertexAttribArray(_color);
glUseProgram(0);
}
};
class PROGRAM_P2_UV_AC4 :public ProgramId
{
public:
typedef int attribute;
typedef int uniform;
public:
attribute _position;
attribute _color;
attribute _uv;
uniform _MVP;
uniform _texture;
//! 第二阶段文理
uniform _texture1;
uniform _uvAnim;
public:
PROGRAM_P2_UV_AC4()
{
_position = -1;
_color = -1;
_uv = -1;
_texture = -1;
_texture1 = -1;
_uvAnim = -1;
_MVP = -1;
}
~PROGRAM_P2_UV_AC4()
{
}
/// 初始化函数
virtual bool initialize()
{
const char* vs =
{
"precision lowp float; "
"uniform mat4 _MVP;"
"attribute vec2 _position;"
"attribute vec2 _uv;"
"attribute vec4 _color;"
"varying vec4 _outColor;"
"varying vec2 _outUV;"
"void main()"
"{"
" vec4 pos = vec4(_position,0,1);"
" _outColor = _color;"
" _outUV = _uv;"
" gl_Position = _MVP * pos;"
"}"
};
const char* ps =
{
"precision lowp float; "
"uniform sampler2D _texture;\n"
"uniform sampler2D _texture1;\n"
"uniform float _uvAnim;\n"
"varying vec4 _outColor;\n"
"varying vec2 _outUV;\n"
"void main()"
"{"
" vec4 tColor0 = texture2D(_texture,_outUV);\n"
" vec2 newUV = vec2(_uvAnim + _outUV.x,_outUV.y);"
" vec4 tColor1 = texture2D(_texture1,newUV);\n"
" gl_FragColor = tColor0 * tColor1;\n"
"}"
};
bool res = createProgram(vs, ps);
if (res)
{
_position = glGetAttribLocation(_programId, "_position");
_color = glGetAttribLocation(_programId, "_color");
_uv = glGetAttribLocation(_programId, "_uv");
_texture = glGetUniformLocation(_programId, "_texture");
_texture1 = glGetUniformLocation(_programId, "_texture1");
_MVP = glGetUniformLocation(_programId, "_MVP");
_uvAnim = glGetUniformLocation(_programId, "_uvAnim");
}
return res;
}
/**
* 使用程序
*/
virtual void begin()
{
glUseProgram(_programId);
glEnableVertexAttribArray(_position);
glEnableVertexAttribArray(_uv);
glEnableVertexAttribArray(_color);
}
/**
* 使用完成
*/
virtual void end()
{
glDisableVertexAttribArray(_position);
glDisableVertexAttribArray(_uv);
glDisableVertexAttribArray(_color);
glUseProgram(0);
}
};
class PROGRAM_P3_UV :public ProgramId
{
public:
typedef int attribute;
typedef int uniform;
public:
attribute _position;
attribute _uv;
uniform _MVP;
uniform _texture;
public:
PROGRAM_P3_UV()
{
_position = -1;
_uv = -1;
_texture = -1;
_MVP = -1;
}
~PROGRAM_P3_UV()
{
}
/// 初始化函数
virtual bool initialize()
{
const char* vs =
{
"precision lowp float; "
"uniform mat4 _MVP;"
"attribute vec2 _position;"
"attribute vec2 _uv;"
"varying vec2 _outUV;"
"void main()"
"{"
" vec4 pos = vec4(_position,0,1);"
" _outUV = _uv;"
" gl_Position = _MVP * pos;"
"}"
};
const char* ps =
{
"precision lowp float; "
"uniform sampler2D _texture;\n"
"varying vec2 _outUV;\n"
"void main()"
"{"
" vec4 tColor0 = texture2D(_texture,_outUV);\n"
" gl_FragColor = tColor0;\n"
"}"
};
bool res = createProgram(vs, ps);
if (res)
{
_position = glGetAttribLocation(_programId, "_position");
_uv = glGetAttribLocation(_programId, "_uv");
_texture = glGetUniformLocation(_programId, "_texture");
_MVP = glGetUniformLocation(_programId, "_MVP");
}
return res;
}
/**
* 使用程序
*/
virtual void begin()
{
glUseProgram(_programId);
glEnableVertexAttribArray(_position);
glEnableVertexAttribArray(_uv);
}
/**
* 使用完成
*/
virtual void end()
{
glDisableVertexAttribArray(_position);
glDisableVertexAttribArray(_uv);
glUseProgram(0);
}
};
class PROGRAM_P2_T2_C3 :public ProgramId
{
public:
typedef int location;
public:
location _positionAttr;
location _colorAttr;
location _uvAttr;
location _MVP;
location _texture;
public:
PROGRAM_P2_T2_C3()
{
_positionAttr = -1;
_colorAttr = -1;
_uvAttr = -1;
_MVP = -1;
}
~PROGRAM_P2_T2_C3()
{
}
/// 初始化函数
virtual bool initialize()
{
const char* vs =
{
"uniform mat4 _MVP;"
"attribute vec3 _position;"
"attribute vec4 _color;"
"attribute vec2 _uv;"
"varying vec4 _outColor;"
"varying vec2 _outUV;"
"void main()"
"{"
" vec4 pos=vec4(_position.x,_position.y,_position.z,1);"
"gl_Position=_MVP*pos;"
"_outColor=_color;"
"_outUV=_uv;"
"}"
};
const char* ps =
{
"precision lowp float;"
"uniform sampler2D _texture;"
"varying vec4 _outColor;"
"varying vec2 _outUV;"
"void main()"
"{"
"vec4 color=texture2D(_texture,_outUV);"
"gl_FragColor=color*_outColor;"//向量相乘变暗,相加变亮
"}"
};
bool res = createProgram(vs,ps);
if (res)
{
_positionAttr = glGetAttribLocation(_programId, "_position");
_colorAttr = glGetAttribLocation(_programId, "_color");
_uvAttr = glGetAttribLocation(_programId, "_uv");
_MVP = glGetUniformLocation(_programId, "_MVP");
_texture = glGetUniformLocation(_programId, "_texture");
}
return res;
}
/**
* 使用程序
*/
virtual void begin()
{
glUseProgram(_programId);
glEnableVertexAttribArray(_positionAttr);
glEnableVertexAttribArray(_uvAttr);
glEnableVertexAttribArray(_colorAttr);
}
/**
* 使用完成
*/
virtual void end()
{
glDisableVertexAttribArray(_positionAttr);
glDisableVertexAttribArray(_uvAttr);
glDisableVertexAttribArray(_colorAttr);
glUseProgram(0);
}
};
窗口绘制类
#pragma once
#include <Windows.h>
#include <tchar.h>
#include <math.h>
#include <EGL/egl.h>
#include <gles2/gl2.h>
#include "freeImage/FreeImage.h"
#include "CELLMath.hpp"
#include "CELLShader.hpp"
namespace CELL
{
class FirstCameraInfor
{
public:
FirstCameraInfor()
{
_moveSpeed = 5;
_eye = CELL::float3(0.0f, 10.0f, 0.0f);
_look = CELL::float3(0.5f, -0.4f, -0.5f);
_up = CELL::float3(0, 1, 0);
_right = CELL::float3(1, 0, 0);
}
CELL::float3 _eye;
CELL::float3 _look;
CELL::float3 _up;
CELL::float3 _right;
float _moveSpeed;
public:
void updateCamera(float fElapsed)
{
CELL::float3 tmpLook = _look;
CELL::float3 dir = _look - _eye;
dir = normalize(dir);
//! 这里调用windows函数获取键盘的状态
unsigned char keys[256];
GetKeyboardState(keys);
if (keys[VK_UP] & 0x80)
{
_eye -= dir*-_moveSpeed * fElapsed;
_look -= dir*-_moveSpeed * fElapsed;
}
if (keys[VK_DOWN] & 0x80)
{
_eye += (dir*-_moveSpeed) * fElapsed;
_look += (dir*-_moveSpeed) * fElapsed;
}
if (keys[VK_LEFT] & 0x80)
{
_eye -= (_right*_moveSpeed) * fElapsed;
_look -= (_right*_moveSpeed) * fElapsed;
}
if (keys[VK_RIGHT] & 0x80)
{
_eye += (_right*_moveSpeed) * fElapsed;
_look += (_right*_moveSpeed) * fElapsed;
}
}
};
class CELLWinApp
{
public:
//! 实例句柄
HINSTANCE _hInstance;
//! 窗口句柄
HWND _hWnd;
//! 窗口的高度
int _width;
//! 窗口的宽度
int _height;
/// for gles2.0
EGLConfig _config;
EGLSurface _surface;
EGLContext _context;
EGLDisplay _display;
//! 增加shader
PROGRAM_P2_T2_C3 _shader;
unsigned _textureId;
FirstCameraInfor _camera;
public:
CELLWinApp(HINSTANCE hInstance)
:_hInstance(hInstance)
{
WNDCLASSEX winClass;
winClass.lpszClassName = _T("CELLWinApp");
winClass.cbSize = sizeof(winClass);
winClass.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
winClass.lpfnWndProc = wndProc;
winClass.hInstance = hInstance;
winClass.hIcon = 0;
winClass.hIconSm = 0;
winClass.hCursor = LoadCursor(hInstance, IDC_ARROW);
winClass.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
winClass.lpszMenuName = NULL;
winClass.cbClsExtra = 0;
winClass.cbWndExtra = 0;
RegisterClassEx(&winClass);
_textureId = 0;
}
virtual ~CELLWinApp()
{
UnregisterClass(_T("CELLWinApp"), _hInstance);
}
/**
* 初始化 OpenGLES2.0
*/
bool initOpenGLES20()
{
const EGLint attribs[] =
{
EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
EGL_BLUE_SIZE, 8,
EGL_GREEN_SIZE, 8,
EGL_RED_SIZE, 8,
EGL_DEPTH_SIZE, 24,
EGL_NONE
};
EGLint format(0);
EGLint numConfigs(0);
EGLint major;
EGLint minor;
//! 1
_display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
//! 2init
eglInitialize(_display, &major, &minor);
//! 3
eglChooseConfig(_display, attribs, &_config, 1, &numConfigs);
eglGetConfigAttrib(_display, _config, EGL_NATIVE_VISUAL_ID, &format);
//! 4
_surface = eglCreateWindowSurface(_display, _config, _hWnd, NULL);
//! 5
EGLint attr[] = { EGL_CONTEXT_CLIENT_VERSION, 2, EGL_NONE, EGL_NONE };
_context = eglCreateContext(_display, _config, 0, attr);
//! 6
if (eglMakeCurrent(_display, _surface, _surface, _context) == EGL_FALSE)
{
return false;
}
eglQuerySurface(_display, _surface, EGL_WIDTH, &_width);
eglQuerySurface(_display, _surface, EGL_HEIGHT, &_height);
return true;
}
/**
* 销毁OpenGLES2.0
*/
void destroyOpenGLES20()
{
glDeleteTextures(1, &_textureId);
if (_display != EGL_NO_DISPLAY)
{
eglMakeCurrent(_display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
if (_context != EGL_NO_CONTEXT)
{
eglDestroyContext(_display, _context);
}
if (_surface != EGL_NO_SURFACE)
{
eglDestroySurface(_display, _surface);
}
eglTerminate(_display);
}
_display = EGL_NO_DISPLAY;
_context = EGL_NO_CONTEXT;
_surface = EGL_NO_SURFACE;
}
virtual unsigned loadMimMap(char* fileNames[], int size)
{
unsigned textureId = 0;
//生成纹理 函数原型：glGenTextures(GLsizei n, GLuint *textures)
//n:用来生成纹理的数量 textures:存储纹理索引的第一个元素指针
glGenTextures(1, &textureId);
//绑定纹理
glBindTexture(GL_TEXTURE_2D,textureId);
//指定纹理的放大，缩小滤波方式,即当图片放大时的插值方式
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
for (int j = 0; j < size;++j)
{
//1-获取图片格式
FREE_IMAGE_FORMAT fifmt = FreeImage_GetFileType(fileNames[j],0);
//2-加载图片
FIBITMAP *dib = FreeImage_Load(fifmt,fileNames[j],0);
//3-转换为rgb 24色
dib = FreeImage_ConvertTo24Bits(dib);
//4-获取数据指针
BYTE *pixels = (BYTE*)FreeImage_GetBits(dib);
int width = FreeImage_GetWidth(dib);
int height = FreeImage_GetHeight(dib);
//像素反转 opengles需要的像素格式RGB，windows图像格式BGR
for (int i = 0; i < width*height*3; i+=3)
{
BYTE temp = pixels[i];
pixels[i] = pixels[i + 2];
pixels[i + 2] = temp;
}
//将图片的rgb数据上传给opengl
glTexImage2D(
GL_TEXTURE_2D,//指定是二维图片
j,//指定级别,纹理可以做mipmap,距离近的就采用级别大的,远则使用较小纹理 j越大则纹理越小
GL_RGB,//纹理使用的存储格式
width,//宽度,老一点的显卡,不支持不规则纹理,即宽，高要是2^n
height,
0,//是否带边框
GL_RGB,//数据的格式,在bmp中,windows存储的数据格式是bgr
GL_UNSIGNED_BYTE,//数据是8bit数据
pixels
);
FreeImage_Unload(dib);
}
return textureId;
}
virtual unsigned loadTexture(const char* fileName)
{
unsigned textureId = 0;
//1 获取图片格式
FREE_IMAGE_FORMAT fifmt = FreeImage_GetFileType(fileName, 0);
//2 加载图片
FIBITMAP *dib = FreeImage_Load(fifmt, fileName, 0);
//3 转化为rgb 24色
dib = FreeImage_ConvertTo24Bits(dib);
//4 获取数据指针
BYTE *pixels = (BYTE*)FreeImage_GetBits(dib);
int width = FreeImage_GetWidth(dib);
int height = FreeImage_GetHeight(dib);
for (int i = 0; i < width * height * 3; i += 3)
{
BYTE temp = pixels[i];
pixels[i] = pixels[i + 2];
pixels[i + 2] = temp;
}
/**
* 产生一个纹理Id,可以认为是纹理句柄，后面的操作将书用这个纹理id
*/
glGenTextures(1, &textureId);
/**
* 使用这个纹理id,或者叫绑定(关联)
*/
glBindTexture(GL_TEXTURE_2D, textureId);
/**
* 指定纹理的放大,缩小滤波，使用线性方式，即当图片放大的时候插值方式
*/
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR_MIPMAP_LINEAR);
/**
* 将图片的rgb数据上传给opengl.
*/
glTexImage2D(
GL_TEXTURE_2D, //! 指定是二维图片
0, //! 指定为第一级别，纹理可以做mipmap,即lod,离近的就采用级别大的，远则使用较小的纹理
GL_RGB, //! 纹理的使用的存储格式
width, //! 宽度，老一点的显卡，不支持不规则的纹理，即宽度和高度不是2^n。
height, //! 宽度，老一点的显卡，不支持不规则的纹理，即宽度和高度不是2^n。
0, //! 是否的边
GL_RGB, //! 数据的格式，bmp中，windows,操作系统中存储的数据是bgr格式
GL_UNSIGNED_BYTE, //! 数据是8bit数据
pixels
);
/**
* 释放内存
*/
FreeImage_Unload(dib);
return textureId;
}
protected:
static LRESULT CALLBACK wndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
CELLWinApp* pThis = (CELLWinApp*)GetWindowLong(hWnd, GWL_USERDATA);
if (pThis)
{
return pThis->onEvent(hWnd, msg, wParam, lParam);
}
if (WM_CREATE == msg)
{
CREATESTRUCT* pCreate = (CREATESTRUCT*)lParam;
SetWindowLong(hWnd, GWL_USERDATA, (DWORD_PTR)pCreate->lpCreateParams);
}
return DefWindowProc(hWnd, msg, wParam, lParam);
}
public:
/**
* 事件函数
*/
virtual LRESULT onEvent(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch (msg)
{
case WM_CLOSE:
case WM_DESTROY:
{
::PostQuitMessage(0);
}
break;
case WM_MOUSEMOVE:
break;
default:
return DefWindowProc(hWnd, msg, wParam, lParam);
}
return S_OK;
}
virtual void render()
{
glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
glViewport(0, 0, _width, _width);
struct Vertex
{
float x, y, z;
float u, v;
float r, g, b, a;
};
_camera.updateCamera(0.016f);
//摄像机观察矩阵
CELL::matrix4 matView = CELL::lookAt(_camera._eye, _camera._look, _camera._up);
float gSize = 100;
float gPos = -5;
float rept = 100;
Vertex grounds[] =
{
{ -gSize, gPos, -gSize, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f },
{ gSize, gPos, -gSize, rept, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f },
{ gSize, gPos, gSize, rept, rept, 1.0f, 1.0f, 1.0f, 1.0f },
{ -gSize, gPos, -gSize, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f },
{ gSize, gPos, gSize, rept, rept, 1.0f, 1.0f, 1.0f, 1.0f },
{ -gSize, gPos, gSize, 0.0f, rept, 1.0f, 1.0f, 1.0f, 1.0f },
};
_shader.begin();
{
//物体变换矩阵
CELL::matrix4 matWorld(1);
//投影矩阵
CELL::matrix4 matProj = CELL::perspective(45.0f, (GLfloat)_width / (GLfloat)_height, 0.1f, 100.0f);
//总的变换矩阵
CELL::matrix4 MVP = matProj * matView * matWorld;
glUniform1i(_shader._texture, 0);
//! 绘制地面
glBindTexture(GL_TEXTURE_2D, _textureId);
//更新shader中各个变量的值
glUniformMatrix4fv(_shader._MVP, 1, false, MVP.data());
glVertexAttribPointer(_shader._positionAttr, 3, GL_FLOAT, false, sizeof(Vertex), &grounds[0].x);
glVertexAttribPointer(_shader._uvAttr, 2, GL_FLOAT, false, sizeof(Vertex), &grounds[0].u);
glVertexAttribPointer(_shader._colorAttr, 4, GL_FLOAT, false, sizeof(Vertex), &grounds[0].r);
glDrawArrays(GL_TRIANGLES, 0, sizeof(grounds) / sizeof(grounds[0]));
}
_shader.end();
}
/**
* 主函数
*/
int main(int width, int height)
{
_hWnd = CreateWindowEx(NULL,
_T("CELLWinApp"),
_T("CELLWinApp"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,
CW_USEDEFAULT,
width,
height,
NULL,
NULL,
_hInstance,
this
);
if (_hWnd == 0)
{
return -1;
}
UpdateWindow(_hWnd);
ShowWindow(_hWnd, SW_SHOW);
if (!initOpenGLES20())
{
return false;
}
_shader.initialize();
char* files[] =
{
"Debug/data/image/tex33X32.bmp",
"Debug/data/image/tex16X16.bmp",
"Debug/data/image/tex8x8.bmp",
"Debug/data/image/tex4x4.bmp",
"Debug/data/image/tex2X2.bmp",
"Debug/data/image/tex1x1.bmp",
};
_textureId = loadMimMap(files, sizeof(files) / sizeof(files[0]));
_camera._eye = CELL::float3(1, 1, 1);
_camera._look = CELL::float3(0.5f, -0.4f, -5.5f);
_camera._up = CELL::float3(0.0f, 1.0f, 0.0f);
_camera._right = CELL::float3(1.0f, 0.0f, 0.0f);
MSG msg = { 0 };
while (msg.message != WM_QUIT)
{
if (msg.message == WM_DESTROY ||
msg.message == WM_CLOSE)
{
break;
}
/**
* 有消息，处理消息，无消息，则进行渲染绘制
*/
if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
else
{
render();
eglSwapBuffers(_display, _surface);
}
}
/**
* 销毁OpenGLES20
*/
destroyOpenGLES20();
return 0;
}
};
}
程序入口
#include "CELLWinApp.hpp"
int APIENTRY _tWinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPTSTR lpCmdLine,
int nCmdShow)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(hInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
UNREFERENCED_PARAMETER(nCmdShow);
CELL::CELLWinApp app(hInstance);
app.main(800, 600);
return 0;
}
完整代码下载地址：http://download.csdn.net/detail/hb707934728/9837338