swift + GLSL 紋理金字塔
前言
以前有一篇使用OpenGL實現金字塔效果的文章。本篇繼續使用swift+GLSL實現這一效果，併爲金字塔加上圖片與顏色混合的紋理效果。git
代碼
swift代碼
代碼以下所示，註釋詳細，其中的問題點解決方案都加了註釋連接：github
import UIKit
import OpenGLES
import CoreGraphics
class DowImageView: UIView {
private var mEaglLayer: CAEAGLLayer?
private var mContext: EAGLContext?
//一些id標記
private var mColorRenderBuffer = GLuint()
private var mColorFrameBuffer = GLuint()
private var mprograme = GLuint()
//旋轉角度
public var xDegree: Float = 0.0 {
didSet {
self.renderLayer()
}
}
public var yDegree: Float = 0.0
{
didSet {
self.renderLayer()
}
}
public var zDegree: Float = 0.0{
didSet {
self.renderLayer()
}
}
//How do you override layerClass in swift: https://stackoverflow.com/questions/24351102/how-do-you-override-layerclass-in-swift
override class var layerClass: AnyClass {
get {
return CAEAGLLayer.self
}
}
/**繪圖流程
1.建立圖層
2.建立上下文
3.清空緩存區
4.設置RenderBuffer
5.設置FrameBuffer
6.開始繪製
*/
override func layoutSubviews() {
setupLayer()
setupContext()
deleteRenderAndFrameBuffer()
setupRenderBuffer()
setupFrameBuffer()
renderLayer()
}
private func setupLayer() {
mEaglLayer = self.layer as? CAEAGLLayer
mEaglLayer?.isOpaque = true
self.contentScaleFactor = UIScreen.main.scale
//kEAGLDrawablePropertyRetainedBacking:繪圖表面顯示後，是否保留其內容
//kEAGLColorFormatRGBA8：32位RGBA的顏色，4*8=32位
//kEAGLColorFormatRGB565：16位RGB的顏色，
//kEAGLColorFormatSRGBA8：sRGB表明了標準的紅、綠、藍，即CRT顯示器、LCD顯示器、投影機、打印機以及其餘設備中色彩再現所使用的三個基本色素。sRGB的色彩空間基於獨立的色彩座標，可使色彩在不一樣的設備使用傳輸中對應於同一個色彩座標體系，而不受這些設備各自具備的不一樣色彩座標的影響。
mEaglLayer?.drawableProperties = [kEAGLDrawablePropertyRetainedBacking: false,
kEAGLDrawablePropertyColorFormat: kEAGLColorFormatRGBA8]
}
private func setupContext() {
let context = EAGLContext(api: EAGLRenderingAPI.openGLES2)
EAGLContext.setCurrent(context)
mContext = context
}
//清空緩存區
private func deleteRenderAndFrameBuffer() {
/*
buffer分爲frame buffer 和 render buffer2個大類。
其中frame buffer 至關於render buffer的管理者。
frame buffer object即稱FBO。
render buffer則又可分爲3類。colorBuffer、depthBuffer、stencilBuffer。
*/
glDeleteBuffers(1, &mColorRenderBuffer)
mColorRenderBuffer = 0
glDeleteBuffers(1, &mColorFrameBuffer)
mColorFrameBuffer = 0
}
private func setupRenderBuffer() {
//定義一個緩存區id
var buffer = GLuint()
//申請緩存區id
glGenRenderbuffers(1, &buffer)
mColorRenderBuffer = buffer
//將id綁定到GL_RENDERBUFFER
glBindRenderbuffer(GLenum(GL_RENDERBUFFER), mColorRenderBuffer)
//綁定renderBuffer併爲其分配存儲空間
//https://developer.apple.com/documentation/opengles/eaglcontext/1622262-renderbufferstorage
mContext?.renderbufferStorage(Int(GL_RENDERBUFFER), from: mEaglLayer)
}
private func setupFrameBuffer() {
var buffer = GLuint()
glGenFramebuffers(1, &buffer)
mColorFrameBuffer = buffer
glBindFramebuffer(GLenum(GL_FRAMEBUFFER), mColorFrameBuffer)
//生成幀緩存區以後，須要將renderbuffer跟framebuffer進行綁定,framebuffer用於管理renderbuffer
glFramebufferRenderbuffer(GLenum(GL_FRAMEBUFFER), GLenum(GL_COLOR_ATTACHMENT0), GLenum(GL_RENDERBUFFER), mColorRenderBuffer)
}
private func renderLayer() {
glClearColor(0.9, 0.8, 0.5, 1.0)
glClear(GLbitfield(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT))
glEnable(GLenum(GL_DEPTH_TEST))
let scale = UIScreen.main.scale
let frame = self.frame
//設置視口
glViewport(0, 0, GLsizei(frame.size.width * scale), GLsizei(frame.size.height * scale))
//讀取頂點、片元着色程序
let verFile = Bundle.main.path(forResource: "shaderv", ofType: "vsh")
let fragFile = Bundle.main.path(forResource: "shaderf", ofType: "fsh")
if (mprograme != 0) {
glDeleteProgram(mprograme)
mprograme = 0
}
//將着色程序綁定到program
attachToProgram(with: verFile, fragFIle: fragFile)
//連接
glLinkProgram(mprograme)
//獲取連接狀態
var linkStatus = GLint()
glGetProgramiv(mprograme, GLenum(GL_LINK_STATUS), &linkStatus)
if linkStatus == GL_FALSE {
var message = [GLchar]()
glGetProgramInfoLog(mprograme, GLsizei(MemoryLayout<GLchar>.size * 512), nil, &message)
let errorInfo = String(cString: message, encoding: .utf8)
print("programErrorInfo" + (errorInfo ?? ""))
return
}
print("🍺🍻 link success")
glUseProgram(mprograme)
//頂點 & 顏色 & 紋理
let attrArr: [GLfloat] = [
-0.5, 0.5, 0.0, 0.0, 0.2, 0.3, 0.0, 1.0,//左上
0.5, 0.5, 0.0, 0.4, 0.5, 0.0, 1.0, 1.0,//右上
-0.5, -0.5, 0.0, 0.5, 0.9, 1.0, 0.0, 0.0,//左下
0.5, -0.5, 0.0, 0.0, 0.4, 0.5, 1.0, 0.0,//右下
0.0, 0.0, 1.0, 1.0, 0.0, 1.0, 0.5, 0.5,//頂點
]
//索引
let indices: [GLuint] = [
0, 3, 2,
0, 1, 3,
0, 2, 4,
0, 4, 1,
2, 3, 4,
1, 4, 3,
]
//頂點數據處理
var attrBuffer = GLuint()
glGenBuffers(1, &attrBuffer)
glBindBuffer(GLenum(GL_ARRAY_BUFFER), attrBuffer)
//由內存copy到顯存
glBufferData(GLenum(GL_ARRAY_BUFFER), MemoryLayout<GLfloat>.size * 40, attrArr, GLenum(GL_DYNAMIC_DRAW))
//將頂點數據經過mPrograme傳遞到頂點着色程序的position
//用來獲取vertex attribute的入口.第二參數字符串必須和shaderv.vsh中的輸入變量：position保持一致
let position = glGetAttribLocation(mprograme, "position")
//設置合適的格式從buffer裏面讀取數據
glEnableVertexAttribArray(GLuint(position))
//設置讀取方式
//arg1：index,頂點數據的索引
//arg2：size,每一個頂點屬性的組件數量，1，2，3，或者4.默認初始值是4.
//arg3：type,數據中的每一個組件的類型，經常使用的有GL_FLOAT,GL_BYTE,GL_SHORT。默認初始值爲GL_FLOAT
//arg4：normalized,固定點數據值是否應該歸一化，或者直接轉換爲固定值。（GL_FALSE）
//arg5：stride,連續頂點屬性之間的偏移量，默認爲0；
//arg6：指定一個指針，指向數組中的第一個頂點屬性的第一個組件。默認爲0
glVertexAttribPointer(GLuint(position), 3, GLenum(GL_FLOAT), GLboolean(GL_FALSE), GLsizei(MemoryLayout<GLfloat>.size * 8), nil)
//頂點顏色
let positionColor = glGetAttribLocation(mprograme, "positionColor")
glEnableVertexAttribArray(GLuint(positionColor))
glVertexAttribPointer(GLuint(positionColor), 3, GLenum(GL_FLOAT), GLboolean(GL_FALSE), GLsizei(MemoryLayout<GLfloat>.size * 8), BUFFER_OFFSET(MemoryLayout<GLfloat>.size * 3))
//處理紋理數據
let textCoor = glGetAttribLocation(mprograme, "textCoordinate")
glEnableVertexAttribArray(GLuint(textCoor))
//此處bufferoffset取值應注意：https://stackoverflow.com/questions/56535272/whats-wrong-when-i-custom-an-imageview-by-opengles
glVertexAttribPointer(GLuint(textCoor), 2, GLenum(GL_FLOAT), GLboolean(GL_FALSE), GLsizei(MemoryLayout<GLfloat>.size * 8), BUFFER_OFFSET(MemoryLayout<GLfloat>.size * 6))
loadTexture(with: "yang")
//設置紋理採樣器 0張紋理
glUniform1i(glGetUniformLocation(mprograme, "colorMap"), 0)
//獲取mProgram中的2個矩陣地址，找到f返回地址，沒有返回-1
let projectionMatrixSlot = glGetUniformLocation(mprograme, "projectionMatrix")
let modelViewMatrixSlot = glGetUniformLocation(mprograme, "modelViewMatrix")
let width = self.frame.size.width
let height = self.frame.size.height
let aspect = width / height
//建立一個單元矩陣
var projectionMatrix: KSMatrix4 = KSMatrix4()
ksMatrixLoadIdentity(&projectionMatrix)
//獲取透視矩陣
/*
arg1：矩陣
arg2：視角，度數爲單位
arg3：縱橫比
arg4：近平面距離
arg5：遠平面距離
*/
ksPerspective(&projectionMatrix, 10.0, Float(aspect), 5.0, 20.0)
//將投影矩陣傳遞到頂點着色器
/*
參數列表：
location:指要更改的uniform變量的位置
count:更改矩陣的個數
transpose:是否要轉置矩陣，並將它做爲uniform變量的值。必須爲GL_FALSE
value:執行count個元素的指針，用來更新指定uniform變量
*/
glUniformMatrix4fv(projectionMatrixSlot, GLsizei(1), GLboolean(GL_FALSE), &projectionMatrix.m.0.0)
//模型視圖矩陣
var modelViewMatrix: KSMatrix4 = KSMatrix4()
ksMatrixLoadIdentity(&modelViewMatrix)
ksTranslate(&modelViewMatrix, 0.0, 0.0, -10.0)
//旋轉矩陣
var rotationMatrix: KSMatrix4 = KSMatrix4()
ksMatrixLoadIdentity(&rotationMatrix)
//旋轉
ksRotate(&rotationMatrix, xDegree, 1.0, 0.0, 0.0)
ksRotate(&rotationMatrix, yDegree, 0.0, 1.0, 0.0)
ksRotate(&rotationMatrix, zDegree, 0.0, 0.0, 1.0)
var tmpModelViewMatrix = modelViewMatrix
ksMatrixMultiply(&modelViewMatrix, &rotationMatrix, &tmpModelViewMatrix)
//將模型視圖矩陣傳遞到頂點着色器
/*
location:指要更改的uniform變量的位置
count:更改矩陣的個數
transpose:是否要轉置矩陣，並將它做爲uniform變量的值。必須爲GL_FALSE
value:執行count個元素的指針，用來更新指定uniform變量
*/
glUniformMatrix4fv(modelViewMatrixSlot, GLsizei(1), GLboolean(GL_FALSE), &modelViewMatrix.m.0.0)
//開啓正背面剔除
glEnableClientState(GLenum(GL_CULL_FACE))
//使用索引繪圖
/*
參數列表：
mode:要呈現的畫圖的模型
GL_POINTS
GL_LINES
GL_LINE_LOOP
GL_LINE_STRIP
GL_TRIANGLES
GL_TRIANGLE_STRIP
GL_TRIANGLE_FAN
count:繪圖個數
type:類型
GL_BYTE
GL_UNSIGNED_BYTE
GL_SHORT
GL_UNSIGNED_SHORT
GL_INT
GL_UNSIGNED_INT
indices：繪製索引數組
*/
glDrawElements(GLenum(GL_TRIANGLES), GLsizei(indices.count), GLenum(GL_UNSIGNED_INT), indices)
mContext?.presentRenderbuffer(Int(GL_RENDERBUFFER))
}
private func BUFFER_OFFSET(_ i: Int) -> UnsafeRawPointer? {
return UnsafeRawPointer(bitPattern: i)
}
//從圖片加載紋理
private func loadTexture(with name: String) {
guard let spriteImage = UIImage(named: name)?.cgImage else { return }
let width = spriteImage.width
let height = spriteImage.height
//獲取圖片字節數: 寬*高*4（RGBA）
let spriteData = calloc(width * height * 4, MemoryLayout<GLubyte>.size)
//建立上下文
//https://stackoverflow.com/questions/24109149/cgbitmapcontextcreate-error-with-swift
/*
arg1：data,指向要渲染的繪製圖像的內存地址
arg2：width,bitmap的寬度，單位爲像素
arg3：height,bitmap的高度，單位爲像素
arg4：bitPerComponent,內存中像素的每一個組件的位數，好比32位RGBA，就設置爲8
arg5：bytesPerRow,bitmap的沒一行的內存所佔的比特數
arg6: 顏色空間
arg7：colorSpace,bitmap上使用的顏色空間 kCGImageAlphaPremultipliedLast：RGBA
*/
//bitmapInfo: https://blog.csdn.net/ccflying88/article/details/50753795
let spriteContext = CGContext(data: spriteData, width: width, height: height, bitsPerComponent: 8, bytesPerRow: width * 4, space: spriteImage.colorSpace!, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)
//在CGContextRef上繪製圖片
let rect = CGRect(x: 0, y: 0, width: width, height: height)
spriteContext?.draw(spriteImage, in: rect)
//綁定紋理到默認id, 若是隻有一個紋理取0，能夠不激活. 直接傳遞過去.
/**.
1. 申請緩存區標記
2. 綁定紋理緩存區
3. 激活紋理.
4. 設置紋理相關參數
*/
var texture: GLuint = GLuint()
//n:用來生成紋理的數量
glGenTextures(1, &texture)
//當一個紋理被綁定時，對於其目標的GL操做將做用於該綁定的紋理之上，而且對其目標的查詢將返回該綁定紋理的狀態。
glBindTexture(GLenum(GL_TEXTURE_2D), 0)
glActiveTexture(GLenum((texture)))
//設置紋理屬性 過濾方式 環繞方式
glTexParameteri(GLenum(GL_TEXTURE_2D), GLenum(GL_TEXTURE_MIN_FILTER), GL_LINEAR)
glTexParameteri(GLenum(GL_TEXTURE_2D), GLenum(GL_TEXTURE_MAG_FILTER), GL_LINEAR)
glTexParameteri(GLenum(GL_TEXTURE_2D), GLenum(GL_TEXTURE_WRAP_S), GL_CLAMP_TO_EDGE)
glTexParameteri(GLenum(GL_TEXTURE_2D), GLenum(GL_TEXTURE_WRAP_T), GL_CLAMP_TO_EDGE)
//載入紋理數據
/*
arg1：紋理模式，GL_TEXTURE_1D、GL_TEXTURE_2D、GL_TEXTURE_3D
arg2：加載的層次，通常設置爲0
arg3：紋理的顏色值GL_RGBA
arg4：寬
arg5：高
arg6：border，邊界寬度
arg7：format
arg8：type
arg9：紋理數據
*/
glTexImage2D(GLenum(GL_TEXTURE_2D), 0, GL_RGBA, GLsizei(width), GLsizei(height), 0, GLenum(GL_RGBA), GLenum(GL_UNSIGNED_BYTE), spriteData)
free(spriteData)
}
private func attachToProgram(with verFile: String?, fragFIle: String?) {
guard let verFile = verFile, let fragFIle = fragFIle else { return }
var verShader = GLuint()
var fragShader = GLuint()
let program = glCreateProgram()
compileshader(with: &verShader, type: GLenum(GL_VERTEX_SHADER), file: verFile)
compileshader(with: &fragShader, type: GLenum(GL_FRAGMENT_SHADER), file: fragFIle)
glAttachShader(program, verShader)
glAttachShader(program, fragShader)
//綁定後不須要了要釋放掉
glDeleteShader(verShader)
glDeleteShader(fragShader)
mprograme = program
}
private func compileshader(with shader: inout GLuint,
type: GLenum,
file: String) {
//https://github.com/skyfe79/LearningOpenGLES2
let content = try? String(contentsOfFile: file, encoding: String.Encoding.utf8)
let contentCString = content?.cString(using: .utf8)
var source = UnsafePointer<GLchar>(contentCString)
// let content = try? NSString(contentsOfFile: file, encoding: String.Encoding.utf8.rawValue)
// var contentLength: GLint = GLint(Int32(content!.length))
// var contentCString = content?.utf8String
shader = glCreateShader(type)
//將着色器源碼附加到着色器對象上。
//arg1：shader,要編譯的着色器對象
//arg2：numOfStrings,傳遞的源碼字符串數量 1個
//arg3：strings,着色器程序的源碼（真正的着色器程序源碼）
//arg4：lenOfStrings,長度，具備每一個字符串長度的數組，或nil，這意味着字符串是nil終止的
glShaderSource(shader, GLsizei(1),&source, nil)
// glShaderSource(shader, GLsizei(1),&contentCString, &contentLength)
//把着色器源代碼編譯成目標代碼
glCompileShader(shader)
var sucess = GLint()
glGetShaderiv(shader, GLenum(GL_COMPILE_STATUS), &sucess)
if sucess == GL_FALSE {
var message = [GLchar]()
glGetShaderInfoLog(shader, GLsizei(MemoryLayout<GLchar>.size * 512), nil, &message)
let errorInfo = String(cString: message, encoding: .utf8)
print("shaderErrorInfo:" + (errorInfo ?? ""))
}
}
}
複製代碼
其中在編譯shader代碼的時候，我以前的代碼是這麼寫的：swift
let content = try? String(contentsOfFile: file, encoding: String.Encoding.utf8)
var source = UnsafePointer<GLchar>(content)
複製代碼
會報錯api
shaderErrorInfo:ERROR: 0:15: 'premature EOF' : syntax error syntax error
shaderErrorInfo:ERROR: 0:13: 'premature EOF' : syntax error syntax error
複製代碼
根據提示premature EOF表示錯誤不是shader代碼的問題，而是shader代碼沒能被正確讀取，通過很久的查找最後發現是獲取shader代碼後須要將string轉換爲cString，上面的代碼中我給出了兩種實現方案其中一種是由String轉換爲cString，另外一種是經過NSString轉換數組
let content = try? String(contentsOfFile: file, encoding: String.Encoding.utf8)
let contentCString = content?.cString(using: .utf8)
var source = UnsafePointer<GLchar>(contentCString)
複製代碼
or緩存
let content = try? NSString(contentsOfFile: file, encoding: String.Encoding.utf8.rawValue)
var contentLength: GLint = GLint(Int32(content!.length))
var contentCString = content?.utf8String
複製代碼
頂點着色器代碼
attribute vec4 position;
attribute vec4 positionColor;
attribute vec2 textCoordinate;
uniform mat4 projectionMatrix;
uniform mat4 modelViewMatrix;
varying lowp vec2 varyTextCoord;
varying lowp vec4 varyColor;
void main() {
varyTextCoord = textCoordinate;
varyColor = positionColor;
vec4 vPos;
vPos = projectionMatrix * modelViewMatrix * position;
gl_Position = vPos;
}
複製代碼
片元着色器代碼
precision highp float;
varying lowp vec2 varyTextCoord;
varying lowp vec4 varyColor;
uniform sampler2D colorMap;
void main() {
vec4 cs = texture2D(colorMap,varyTextCoord);
vec4 cd = varyColor;
float s = 0.2;
float d = 0.5;
vec4 color = (cs * s) + (cd * d);
gl_FragColor = color;
}
複製代碼
第三方代碼
關於矩陣的操做使用到了kesalin封裝的一份代碼.bash
GLESMath.h
//
// GLESMath.h
//
// Created by kesalin@gmail.com on 12-11-26.
// Copyright (c) 2012. http://blog.csdn.net/kesalin/. All rights reserved.
//
#ifndef __GLESMATH_H__
#define __GLESMATH_H__
#import <OpenGLES/ES2/gl.h>
#include <math.h>
#ifndef M_PI
#define M_PI 3.1415926535897932384626433832795f
#endif
#define DEG2RAD( a ) (((a) * M_PI) / 180.0f)
#define RAD2DEG( a ) (((a) * 180.f) / M_PI)
// angle indexes
#define PITCH 0 // up / down
#define YAW 1 // left / right
#define ROLL 2 // fall over
typedef unsigned char byte;
typedef struct
{
GLfloat m[3][3];
} KSMatrix3;
typedef struct
{
GLfloat m[4][4];
} KSMatrix4;
typedef struct KSVec3 {
GLfloat x;
GLfloat y;
GLfloat z;
} KSVec3;
typedef struct KSVec4 {
GLfloat x;
GLfloat y;
GLfloat z;
GLfloat w;
} KSVec4;
typedef struct {
GLfloat r;
GLfloat g;
GLfloat b;
GLfloat a;
} KSColor;
#ifdef __cplusplus
extern "C" {
#endif
unsigned int ksNextPot(unsigned int n);
void ksCopyMatrix4(KSMatrix4 * target, const KSMatrix4 * src);
void ksMatrix4ToMatrix3(KSMatrix3 * target, const KSMatrix4 * src);
//
/// multiply matrix specified by result with a scaling matrix and return new matrix in result
/// result Specifies the input matrix. Scaled matrix is returned in result.
/// sx, sy, sz Scale factors along the x, y and z axes respectively
//
void ksScale(KSMatrix4 *result, GLfloat sx, GLfloat sy, GLfloat sz);
//
/// multiply matrix specified by result with a translation matrix and return new matrix in result
/// result Specifies the input matrix. Translated matrix is returned in result.
/// tx, ty, tz Scale factors along the x, y and z axes respectively
//
void ksTranslate(KSMatrix4 *result, GLfloat tx, GLfloat ty, GLfloat tz);
//
/// multiply matrix specified by result with a rotation matrix and return new matrix in result
/// result Specifies the input matrix. Rotated matrix is returned in result.
/// angle Specifies the angle of rotation, in degrees.
/// x, y, z Specify the x, y and z coordinates of a vector, respectively
//
void ksRotate(KSMatrix4 *result, GLfloat angle, GLfloat x, GLfloat y, GLfloat z);
//
/// perform the following operation - result matrix = srcA matrix * srcB matrix
/// result Returns multiplied matrix
/// srcA, srcB Input matrices to be multiplied
//
void ksMatrixMultiply(KSMatrix4 *result, const KSMatrix4 *srcA, const KSMatrix4 *srcB);
//
//// return an identity matrix
//// result returns identity matrix
//
void ksMatrixLoadIdentity(KSMatrix4 *result);
//
/// multiply matrix specified by result with a perspective matrix and return new matrix in result
/// result Specifies the input matrix. new matrix is returned in result.
/// fovy Field of view y angle in degrees
/// aspect Aspect ratio of screen
/// nearZ Near plane distance
/// farZ Far plane distance
//
void ksPerspective(KSMatrix4 *result, float fovy, float aspect, float nearZ, float farZ);
//
/// multiply matrix specified by result with a perspective matrix and return new matrix in result
/// result Specifies the input matrix. new matrix is returned in result.
/// left, right Coordinates for the left and right vertical clipping planes
/// bottom, top Coordinates for the bottom and top horizontal clipping planes
/// nearZ, farZ Distances to the near and far depth clipping planes. These values are negative if plane is behind the viewer
//
void ksOrtho(KSMatrix4 *result, float left, float right, float bottom, float top, float nearZ, float farZ);
//
// multiply matrix specified by result with a perspective matrix and return new matrix in result
/// result Specifies the input matrix. new matrix is returned in result.
/// left, right Coordinates for the left and right vertical clipping planes
/// bottom, top Coordinates for the bottom and top horizontal clipping planes
/// nearZ, farZ Distances to the near and far depth clipping planes. Both distances must be positive.
//
void ksFrustum(KSMatrix4 *result, float left, float right, float bottom, float top, float nearZ, float farZ);
#ifdef __cplusplus
}
#endif
#endif // __GLESMATH_H__
複製代碼
GLESMath.c
//
// GLESMath.c
//
// Created by kesalin@gmail.com on 12-11-26.
// Copyright (c) 2012 ƒÍ http://blog.csdn.net/kesalin/. All rights reserved.
//
#include "GLESMath.h"
#include <stdlib.h>
#include <math.h>
void * memcpy(void *, const void *, size_t);
void * memset(void *, int, size_t);
//
// Matrix math utils
//
void ksScale(KSMatrix4 *result, GLfloat sx, GLfloat sy, GLfloat sz)
{
result->m[0][0] *= sx;
result->m[0][1] *= sx;
result->m[0][2] *= sx;
result->m[0][3] *= sx;
result->m[1][0] *= sy;
result->m[1][1] *= sy;
result->m[1][2] *= sy;
result->m[1][3] *= sy;
result->m[2][0] *= sz;
result->m[2][1] *= sz;
result->m[2][2] *= sz;
result->m[2][3] *= sz;
}
void ksTranslate(KSMatrix4 *result, GLfloat tx, GLfloat ty, GLfloat tz)
{
result->m[3][0] += (result->m[0][0] * tx + result->m[1][0] * ty + result->m[2][0] * tz);
result->m[3][1] += (result->m[0][1] * tx + result->m[1][1] * ty + result->m[2][1] * tz);
result->m[3][2] += (result->m[0][2] * tx + result->m[1][2] * ty + result->m[2][2] * tz);
result->m[3][3] += (result->m[0][3] * tx + result->m[1][3] * ty + result->m[2][3] * tz);
}
void ksRotate(KSMatrix4 *result, GLfloat angle, GLfloat x, GLfloat y, GLfloat z)
{
GLfloat sinAngle, cosAngle;
GLfloat mag = sqrtf(x * x + y * y + z * z);
sinAngle = sinf ( angle * M_PI / 180.0f );
cosAngle = cosf ( angle * M_PI / 180.0f );
if ( mag > 0.0f )
{
GLfloat xx, yy, zz, xy, yz, zx, xs, ys, zs;
GLfloat oneMinusCos;
KSMatrix4 rotMat;
x /= mag;
y /= mag;
z /= mag;
xx = x * x;
yy = y * y;
zz = z * z;
xy = x * y;
yz = y * z;
zx = z * x;
xs = x * sinAngle;
ys = y * sinAngle;
zs = z * sinAngle;
oneMinusCos = 1.0f - cosAngle;
rotMat.m[0][0] = (oneMinusCos * xx) + cosAngle;
rotMat.m[0][1] = (oneMinusCos * xy) - zs;
rotMat.m[0][2] = (oneMinusCos * zx) + ys;
rotMat.m[0][3] = 0.0F;
rotMat.m[1][0] = (oneMinusCos * xy) + zs;
rotMat.m[1][1] = (oneMinusCos * yy) + cosAngle;
rotMat.m[1][2] = (oneMinusCos * yz) - xs;
rotMat.m[1][3] = 0.0F;
rotMat.m[2][0] = (oneMinusCos * zx) - ys;
rotMat.m[2][1] = (oneMinusCos * yz) + xs;
rotMat.m[2][2] = (oneMinusCos * zz) + cosAngle;
rotMat.m[2][3] = 0.0F;
rotMat.m[3][0] = 0.0F;
rotMat.m[3][1] = 0.0F;
rotMat.m[3][2] = 0.0F;
rotMat.m[3][3] = 1.0F;
ksMatrixMultiply( result, &rotMat, result );
}
}
void ksMatrixMultiply(KSMatrix4 *result, const KSMatrix4 *srcA, const KSMatrix4 *srcB)
{
KSMatrix4 tmp;
int i;
for (i=0; i<4; i++)
{
tmp.m[i][0] = (srcA->m[i][0] * srcB->m[0][0]) +
(srcA->m[i][1] * srcB->m[1][0]) +
(srcA->m[i][2] * srcB->m[2][0]) +
(srcA->m[i][3] * srcB->m[3][0]) ;
tmp.m[i][1] = (srcA->m[i][0] * srcB->m[0][1]) +
(srcA->m[i][1] * srcB->m[1][1]) +
(srcA->m[i][2] * srcB->m[2][1]) +
(srcA->m[i][3] * srcB->m[3][1]) ;
tmp.m[i][2] = (srcA->m[i][0] * srcB->m[0][2]) +
(srcA->m[i][1] * srcB->m[1][2]) +
(srcA->m[i][2] * srcB->m[2][2]) +
(srcA->m[i][3] * srcB->m[3][2]) ;
tmp.m[i][3] = (srcA->m[i][0] * srcB->m[0][3]) +
(srcA->m[i][1] * srcB->m[1][3]) +
(srcA->m[i][2] * srcB->m[2][3]) +
(srcA->m[i][3] * srcB->m[3][3]) ;
}
memcpy(result, &tmp, sizeof(KSMatrix4));
}
void ksCopyMatrix4(KSMatrix4 * target, const KSMatrix4 * src)
{
memcpy(target, src, sizeof(KSMatrix4));
}
void ksMatrix4ToMatrix3(KSMatrix3 * t, const KSMatrix4 * src)
{
t->m[0][0] = src->m[0][0];
t->m[0][1] = src->m[0][1];
t->m[0][2] = src->m[0][2];
t->m[1][0] = src->m[1][0];
t->m[1][1] = src->m[1][1];
t->m[1][2] = src->m[1][2];
t->m[2][0] = src->m[2][0];
t->m[2][1] = src->m[2][1];
t->m[2][2] = src->m[2][2];
}
void ksMatrixLoadIdentity(KSMatrix4 *result)
{
memset(result, 0x0, sizeof(KSMatrix4));
result->m[0][0] = 1.0f;
result->m[1][1] = 1.0f;
result->m[2][2] = 1.0f;
result->m[3][3] = 1.0f;
}
void ksFrustum(KSMatrix4 *result, float left, float right, float bottom, float top, float nearZ, float farZ)
{
float deltaX = right - left;
float deltaY = top - bottom;
float deltaZ = farZ - nearZ;
KSMatrix4 frust;
if ( (nearZ <= 0.0f) || (farZ <= 0.0f) ||
(deltaX <= 0.0f) || (deltaY <= 0.0f) || (deltaZ <= 0.0f) )
return;
frust.m[0][0] = 2.0f * nearZ / deltaX;
frust.m[0][1] = frust.m[0][2] = frust.m[0][3] = 0.0f;
frust.m[1][1] = 2.0f * nearZ / deltaY;
frust.m[1][0] = frust.m[1][2] = frust.m[1][3] = 0.0f;
frust.m[2][0] = (right + left) / deltaX;
frust.m[2][1] = (top + bottom) / deltaY;
frust.m[2][2] = -(nearZ + farZ) / deltaZ;
frust.m[2][3] = -1.0f;
frust.m[3][2] = -2.0f * nearZ * farZ / deltaZ;
frust.m[3][0] = frust.m[3][1] = frust.m[3][3] = 0.0f;
ksMatrixMultiply(result, &frust, result);
}
void ksPerspective(KSMatrix4 *result, float fovy, float aspect, float nearZ, float farZ)
{
GLfloat frustumW, frustumH;
frustumH = tanf( fovy / 360.0f * M_PI ) * nearZ;
frustumW = frustumH * aspect;
ksFrustum( result, -frustumW, frustumW, -frustumH, frustumH, nearZ, farZ );
}
void ksOrtho(KSMatrix4 *result, float left, float right, float bottom, float top, float nearZ, float farZ)
{
float deltaX = right - left;
float deltaY = top - bottom;
float deltaZ = farZ - nearZ;
KSMatrix4 ortho;
if ( (deltaX == 0.0f) || (deltaY == 0.0f) || (deltaZ == 0.0f) )
return;
ksMatrixLoadIdentity(&ortho);
ortho.m[0][0] = 2.0f / deltaX;
ortho.m[3][0] = -(right + left) / deltaX;
ortho.m[1][1] = 2.0f / deltaY;
ortho.m[3][1] = -(top + bottom) / deltaY;
ortho.m[2][2] = -2.0f / deltaZ;
ortho.m[3][2] = -(nearZ + farZ) / deltaZ;
ksMatrixMultiply(result, &ortho, result);
}
複製代碼
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效果
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每日一句
-
每一个你不满意的现在，都有一个你没有努力的曾经。