Implemented KRMat4::LookAt

KREngine object no longer requires a width and height passed into init.
KRCamera no longer requires a width and height passed into the constructor; it now automatically resizes its buffers to match the active render target.

--HG--
extra : convert_revision : svn%3A7752d6cf-9f14-4ad2-affc-04f1e67b81a5/trunk%40128

KREngine/KREngine/Classes/KRCamera.cpp

@@ -42,9 +42,9 @@
 #import "KRBoundingVolume.h"
 #import "KRStockGeometry.h"
 
-KRCamera::KRCamera(KRContext &context, GLint width, GLint height) : KRContextObject(context) {
+KRCamera::KRCamera(KRContext &context) : KRContextObject(context) {
-    backingWidth = width;
+    backingWidth = 0;
-    backingHeight = height;
+    backingHeight = 0;
     
     
     double const PI = 3.141592653589793f;
@@ -96,6 +96,12 @@ KRCamera::KRCamera(KRContext &context, GLint width, GLint height) : KRContextObj
     
     
     m_cShadowBuffers = 0;
+    compositeDepthTexture = 0;
+    compositeColorTexture = 0;
+    lightAccumulationTexture = 0;
+    compositeFramebuffer = 0;
+    lightAccumulationBuffer = 0;
+    
     
     memset(shadowFramebuffer, sizeof(GLuint) * 3, 0);
     memset(shadowDepthTexture, sizeof(GLuint) * 3, 0);
@@ -104,8 +110,6 @@ KRCamera::KRCamera(KRContext &context, GLint width, GLint height) : KRContextObj
     
     m_skyBoxName = "";
     m_pSkyBoxTexture = NULL;
-    
-    createBuffers();
 }
 
 KRCamera::~KRCamera() {
@@ -139,6 +143,8 @@ void KRCamera::renderFrame(KRScene &scene, KRMat4 &viewMatrix)
     GLint defaultFBO;
     GLDEBUG(glGetIntegerv(GL_FRAMEBUFFER_BINDING, &defaultFBO));
     
+    createBuffers();
+    
     m_pContext->rotateBuffers(true);
     KRMat4 invViewMatrix = viewMatrix;
     invViewMatrix.invert();
@@ -157,7 +163,7 @@ void KRCamera::renderFrame(KRScene &scene, KRMat4 &viewMatrix)
     
     lightDirection.normalize();
     
-    allocateShadowBuffers();
+    allocateShadowBuffers(m_cShadowBuffers);
     int iOffset=m_iFrame % m_cShadowBuffers;
     for(int iShadow2=iOffset; iShadow2 < m_cShadowBuffers + iOffset; iShadow2++) {
         int iShadow = iShadow2 % m_cShadowBuffers;
@@ -202,6 +208,7 @@ void KRCamera::renderFrame(KRScene &scene, KRMat4 &viewMatrix)
 
 
 void KRCamera::renderFrame(KRScene &scene, KRMat4 &viewMatrix, KRVector3 &lightDirection, KRVector3 &cameraPosition) {
+    
     setViewportSize(KRVector2(backingWidth, backingHeight));
     
     
@@ -497,6 +504,16 @@ void KRCamera::renderFrame(KRScene &scene, KRMat4 &viewMatrix, KRVector3 &lightD
 
 
 void KRCamera::createBuffers() {
+    GLint renderBufferWidth = 0, renderBufferHeight = 0;
+    GLDEBUG(glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &renderBufferWidth));
+    GLDEBUG(glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &renderBufferHeight));
+    
+    if(renderBufferWidth != backingWidth || renderBufferHeight != backingHeight) {
+        backingWidth = renderBufferWidth;
+        backingHeight = renderBufferHeight;
+
+        destroyBuffers();
+        
         // ===== Create offscreen compositing framebuffer object =====
         GLDEBUG(glGenFramebuffers(1, &compositeFramebuffer));
         GLDEBUG(glBindFramebuffer(GL_FRAMEBUFFER, compositeFramebuffer));
@@ -537,12 +554,13 @@ void KRCamera::createBuffers() {
         GLDEBUG(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, backingWidth, backingHeight, 0, GL_BGRA, GL_UNSIGNED_BYTE, NULL));
         GLDEBUG(glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, lightAccumulationTexture, 0));
         
-    allocateShadowBuffers();
+        allocateShadowBuffers(m_cShadowBuffers);
+    }
 }
 
-void KRCamera::allocateShadowBuffers() {
+void KRCamera::allocateShadowBuffers(int cBuffers) {
     // First deallocate buffers no longer needed
-    for(int iShadow = m_cShadowBuffers; iShadow < KRENGINE_MAX_SHADOW_BUFFERS; iShadow++) {
+    for(int iShadow = cBuffers; iShadow < KRENGINE_MAX_SHADOW_BUFFERS; iShadow++) {
         if (shadowDepthTexture[iShadow]) {
             GLDEBUG(glDeleteTextures(1, shadowDepthTexture + iShadow));
             shadowDepthTexture[iShadow] = 0;
@@ -555,7 +573,7 @@ void KRCamera::allocateShadowBuffers() {
     }
     
     // Allocate newly required buffers
-    for(int iShadow = 0; iShadow < m_cShadowBuffers; iShadow++) {
+    for(int iShadow = 0; iShadow < cBuffers; iShadow++) {
         if(!shadowDepthTexture[iShadow]) {
             shadowValid[iShadow] = false;
             
@@ -580,8 +598,7 @@ void KRCamera::allocateShadowBuffers() {
 
 void KRCamera::destroyBuffers()
 {
-    m_cShadowBuffers = 0;
+    allocateShadowBuffers(0);
-    allocateShadowBuffers();
     
     if (compositeDepthTexture) {
         GLDEBUG(glDeleteTextures(1, &compositeDepthTexture));

KREngine/KREngine/Classes/KRCamera.h

@@ -52,7 +52,7 @@ class KRContext;
 
 class KRCamera : public KRContextObject {
 public:
-    KRCamera(KRContext &context, GLint width, GLint height);
+    KRCamera(KRContext &context);
     virtual ~KRCamera();
     
     GLint backingWidth, backingHeight;
@@ -60,7 +60,7 @@ public:
     void renderFrame(KRScene &scene, KRMat4 &viewMatrix);
     void renderShadowBuffer(KRScene &scene, int iShadow);
     void invalidateShadowBuffers();
-    void allocateShadowBuffers();
+    void allocateShadowBuffers(int cBuffers);
     void createBuffers();
     
     KRVector3 getPosition() const;

KREngine/KREngine/Classes/KREngine.h

@@ -50,7 +50,7 @@ typedef enum KREngineParameterType {KRENGINE_PARAMETER_INT, KRENGINE_PARAMETER_F
 @property(nonatomic, assign) KRCamera *camera;
 @property(nonatomic, retain) NSString *debug_text;
 
-- (id)initForWidth: (GLuint)width Height: (GLuint)height;
+- (id)init;
 - (BOOL)loadResource:(NSString *)path;
 
 // Parameter enumeration interface

KREngine/KREngine/Classes/KREngine.mm

@@ -51,13 +51,13 @@ using namespace std;
 @synthesize debug_text = _debug_text;
 double const PI = 3.141592653589793f;
 
-- (id)initForWidth: (GLuint)width Height: (GLuint)height
+- (id)init
 {
     _camera = NULL;
     _context = NULL;
     if ((self = [super init])) {
         _context = new KRContext();
-        _camera = new KRCamera(*_context, width, height);
+        _camera = new KRCamera(*_context);
         _parameter_names = [@{
             @"camera_fov" : @0,
             @"shadow_quality" : @1,

KREngine/KREngine/Classes/KRMat4.cpp

@@ -303,3 +303,31 @@ KRVector3 KRMat4::DotWDiv(const KRMat4 &m, const KRVector3 &v) {
     r /= DotW(m, v);
     return r;
 }
+
+KRMat4 KRMat4::LookAt(const KRVector3 &cameraPos, const KRVector3 &lookAtPos, const KRVector3 &upDirection)
+{
+    KRMat4 matLookat;
+    KRVector3 lookat_z_axis = lookAtPos - cameraPos;
+    lookat_z_axis.normalize();
+    KRVector3 lookat_x_axis = KRVector3::Cross(upDirection, lookat_z_axis);
+    lookat_x_axis.normalize();
+    KRVector3 lookat_y_axis = KRVector3::Cross(lookat_z_axis, lookat_x_axis);
+    
+    matLookat.getPointer()[0] = lookat_x_axis.x;
+    matLookat.getPointer()[1] = lookat_y_axis.x;
+    matLookat.getPointer()[2] = lookat_z_axis.x;
+    
+    matLookat.getPointer()[4] = lookat_x_axis.y;
+    matLookat.getPointer()[5] = lookat_y_axis.y;
+    matLookat.getPointer()[6] = lookat_z_axis.y;
+    
+    matLookat.getPointer()[8] = lookat_x_axis.z;
+    matLookat.getPointer()[9] = lookat_y_axis.z;
+    matLookat.getPointer()[10] = lookat_z_axis.z;
+    
+    matLookat.getPointer()[12] = -KRVector3::Dot(lookat_x_axis, cameraPos);
+    matLookat.getPointer()[13] = -KRVector3::Dot(lookat_y_axis, cameraPos);
+    matLookat.getPointer()[14] = -KRVector3::Dot(lookat_z_axis, cameraPos);
+    
+    return matLookat;
+}

KREngine/KREngine/Classes/KRMat4.h

@@ -105,6 +105,8 @@ public:
     static KRVector3 Dot(const KRMat4 &m, const KRVector3 &v);
     static float DotW(const KRMat4 &m, const KRVector3 &v);
     static KRVector3 DotWDiv(const KRMat4 &m, const KRVector3 &v);
+    
+    static KRMat4 LookAt(const KRVector3 &cameraPos, const KRVector3 &lookAtPos, const KRVector3 &upDirection);
 };
 
 #endif // KRMAT4_I