pyramid: moved code around

6 files changed, 103 insertions, 82 deletions

diff --git a/sdl/GL_todo.txt b/sdl/GL_todo.txt
index 4466642..aea6032 100644
--- a/sdl/GL_todo.txt
+++ b/sdl/GL_todo.txt
@@ -11,3 +11,14 @@ todo:
 - obj loader
 - look at mesa's sources and borrow OSD stuff
 - GL error checking and extensions
+- split SDL
+
+notes:
+- texture matrix!?
+- texture filtering: process of calculating color fragments from a stretched or
+  shrunken texture map
+ 
+obj loader:
+- glGenTextures()
+- glBindTextures()
+
diff --git a/sdl/glframe.h b/sdl/glframe.h
index fa5c991..d83f9e4 100644
--- a/sdl/glframe.h
+++ b/sdl/glframe.h
@@ -11,11 +11,11 @@ typedef struct
 } GLFrame;
 
 /* function prototypes */
-void reset_glframe(GLFrame *frame);
-void get_camera_orientation(GLFrame *frame, M3DMatrix44f m);
-void apply_camera_transform(GLFrame *frame);
-void move_forward(GLFrame *frame, float delta);
-void rotate_local_y(GLFrame *frame, float angle);
+void reset_glframe(GLFrame *);
+void get_camera_orientation(GLFrame *, M3DMatrix44f);
+void apply_camera_transform(GLFrame *);
+void move_forward(GLFrame *, float);
+void rotate_local_y(GLFrame *, float);
 
 #endif
 
diff --git a/sdl/gltools.c b/sdl/gltools.c
index 350f3db..d6c518f 100644
--- a/sdl/gltools.c
+++ b/sdl/gltools.c
@@ -164,6 +164,77 @@ GLbyte *gltLoadTGA(const char *szFileName, GLint *iWidth, GLint *iHeight,
     return pBits;
 }
 
+void gltDrawTriangle(void)
+{
+    M3DVector3f vNormal;
+    M3DVector3f vCorners[5] = {
+        { 0.0f, 0.6f, 0.0f },       /* top           0 */
+        { -0.5f, -0.2f, -.50f },    /* back left     1 */
+        { 0.5f, -0.2f, -0.50f },    /* back right    2 */
+        { 0.5f, -0.2f, 0.5f },      /* front right   3 */
+        { -0.5f, -0.2f, 0.5f }      /* front left    4 */
+    };
+
+    glBegin(GL_TRIANGLES);
+        /* bottom section - two triangles */
+        glNormal3f(0.0f, -1.0f, 0.0f);
+
+        /* map texture to geometry */
+        glTexCoord2f(1.0f, 1.0f);
+        glVertex3fv(vCorners[2]);
+        glTexCoord2f(0.0f, 1.0f);
+        glVertex3fv(vCorners[4]);
+        glTexCoord2f(0.0f, 0.0f);
+        glVertex3fv(vCorners[1]);
+        glTexCoord2f(1.0f, 1.0f);
+        glVertex3fv(vCorners[2]);
+        glTexCoord2f(1.0f, 0.0f);
+        glVertex3fv(vCorners[3]);
+        glTexCoord2f(0.0f, 0.0f);
+        glVertex3fv(vCorners[4]);
+        
+        /* front face */
+        m3dFindNormalf(vNormal, vCorners[0], vCorners[4], vCorners[3]);
+        glNormal3fv(vNormal);
+        glTexCoord2f(0.5f, 1.0f);
+        glVertex3fv(vCorners[0]);
+        glTexCoord2f(0.0f, 0.0f);
+        glVertex3fv(vCorners[4]);
+        glTexCoord2f(1.0f, 0.0f);
+        glVertex3fv(vCorners[3]);
+        
+        /* left face */
+        m3dFindNormalf(vNormal, vCorners[0], vCorners[1], vCorners[4]);
+        glNormal3fv(vNormal);
+        glTexCoord2f(0.5f, 1.0f);
+        glVertex3fv(vCorners[0]);
+        glTexCoord2f(0.0f, 0.0f);
+        glVertex3fv(vCorners[1]);
+        glTexCoord2f(1.0f, 0.0f);
+        glVertex3fv(vCorners[4]);
+
+        /* back face */
+        m3dFindNormalf(vNormal, vCorners[0], vCorners[2], vCorners[1]);
+        glNormal3fv(vNormal);
+        glTexCoord2f(0.5f, 1.0f);
+        glVertex3fv(vCorners[0]);
+        glTexCoord2f(0.0f, 0.0f);
+        glVertex3fv(vCorners[2]);
+        glTexCoord2f(1.0f, 0.0f);
+        glVertex3fv(vCorners[1]);
+        
+        /* right face */
+        m3dFindNormalf(vNormal, vCorners[0], vCorners[3], vCorners[2]);
+        glNormal3fv(vNormal);
+        glTexCoord2f(0.5f, 1.0f);
+        glVertex3fv(vCorners[0]);
+        glTexCoord2f(0.0f, 0.0f);
+        glVertex3fv(vCorners[3]);
+        glTexCoord2f(1.0f, 0.0f);
+        glVertex3fv(vCorners[2]);
+    glEnd();
+}
+
 void gltDrawUnitAxes(void)
 {
     GLUquadricObj *pObj; /* temporary, used for quadrics */
@@ -276,7 +347,7 @@ void gltDrawTorus(GLfloat majorRadius, GLfloat minorRadius, GLint numMajor,
 
 /* this function just specifically draws the jet */
 /* FIXME: needs to accepts parameters of location and lightning */
-void DrawJet(int nShadow)
+void gltDrawJet(int nShadow)
 {
     M3DVector3f vNormal;
 
diff --git a/sdl/gltools.h b/sdl/gltools.h
index b960abd..9d5b819 100644
--- a/sdl/gltools.h
+++ b/sdl/gltools.h
@@ -24,9 +24,10 @@ typedef struct
 /* function prototypes */
 GLint gltWriteTGA(const char *);
 GLbyte *gltLoadTGA(const char *, GLint *, GLint *, GLint *, GLenum *);
+void gltDrawTriangle(void);
 void gltDrawUnitAxes(void);
 void gltDrawTorus(GLfloat, GLfloat, GLint, GLint);
-void DrawJet(int);
+void gltDrawJet(int);
 
 #endif
 
diff --git a/sdl/math3d.h b/sdl/math3d.h
index 510c017..c337195 100644
--- a/sdl/math3d.h
+++ b/sdl/math3d.h
@@ -24,13 +24,12 @@ typedef float M3DVector2f[2];   /* vector of 2 floats */
 /* math function prototypes */
 void m3dFindNormalf(M3DVector3f, const M3DVector3f, const M3DVector3f, 
                    const M3DVector3f);
-void m3dLoadIdentity33f(M3DMatrix33f m);
+void m3dLoadIdentity33f(M3DMatrix33f);
 void m3dLoadIdentity44f(M3DMatrix44f);
-void m3dGetPlaneEquationf(M3DVector4f planeEq, const M3DVector3f p1,
-                         const M3DVector3f p2, const M3DVector3f p3);
+void m3dGetPlaneEquationf(M3DVector4f, const M3DVector3f,
+                         const M3DVector3f, const M3DVector3f);
 void m3dRotationMatrix44f(M3DMatrix44f, float, float, float, float);
-void m3dMakePlanarShadowMatrixf(M3DMatrix44f proj, const M3DVector4f planeEq,
-                               const M3DVector3f vLightPos);
+void m3dMakePlanarShadowMatrixf(M3DMatrix44f, const M3DVector4f, const M3DVector3f);
 void m3dMatrixMultiply44f(M3DMatrix44f, const M3DMatrix44f, const M3DMatrix44f);
 
 static inline void m3dCrossProductf(M3DVector3f result, const M3DVector3f u, 
diff --git a/sdl/pyramid.c b/sdl/pyramid.c
index fa78477..fded7c5 100644
--- a/sdl/pyramid.c
+++ b/sdl/pyramid.c
@@ -108,12 +108,18 @@ static void SetupRC()
                  GL_UNSIGNED_BYTE, pBytes);
     free(pBytes);
     
+    /* texture filtering, we modify deafult values since we don't have mipmaps */
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     
+    /* how OpenGL combines the colors from texels with the color of the underlying
+     * geometry is controlled by the texture environment mode */
     glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+    
+    /* once texture is loaded and enabled, it will applied to every primitive
+     * that specifies coordinates */
     glEnable(GL_TEXTURE_2D);
     
     /* set the camera to <0,0,0> */
@@ -241,16 +247,7 @@ static void draw_ground(void)
 }
 
 static void render(void)
-{
-    M3DVector3f vNormal;
-    M3DVector3f vCorners[5] = {
-        { 0.0f, 0.6f, 0.0f },       /* top           0 */
-        { -0.5f, -0.2f, -.50f },    /* back left     1 */
-        { 0.5f, -0.2f, -0.50f },    /* back right    2 */
-        { 0.5f, -0.2f, 0.5f },      /* front right   3 */
-        { -0.5f, -0.2f, 0.5f }      /* front left    4 */
-    };
-                              
+{                              
     /* clear the window with current clearing color */
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
@@ -267,66 +264,8 @@ static void render(void)
         glRotatef(yRot, 0.0f, 1.0f, 0.0f);
 
         /* draw the pyramid */
-        glColor3f(1.0f, 1.0f, 1.0f);
-        glBegin(GL_TRIANGLES);
-        
-            /* bottom section - two triangles */
-            glNormal3f(0.0f, -1.0f, 0.0f);
-
-            /* map texture to geometry */
-            glTexCoord2f(1.0f, 1.0f);
-            glVertex3fv(vCorners[2]);
-            glTexCoord2f(0.0f, 1.0f);
-            glVertex3fv(vCorners[4]);
-            glTexCoord2f(0.0f, 0.0f);
-            glVertex3fv(vCorners[1]);
-            glTexCoord2f(1.0f, 1.0f);
-            glVertex3fv(vCorners[2]);
-            glTexCoord2f(1.0f, 0.0f);
-            glVertex3fv(vCorners[3]);
-            glTexCoord2f(0.0f, 0.0f);
-            glVertex3fv(vCorners[4]);
-            
-            /* front face */
-            m3dFindNormalf(vNormal, vCorners[0], vCorners[4], vCorners[3]);
-            glNormal3fv(vNormal);
-            glTexCoord2f(0.5f, 1.0f);
-            glVertex3fv(vCorners[0]);
-            glTexCoord2f(0.0f, 0.0f);
-            glVertex3fv(vCorners[4]);
-            glTexCoord2f(1.0f, 0.0f);
-            glVertex3fv(vCorners[3]);
-            
-            /* left face */
-            m3dFindNormalf(vNormal, vCorners[0], vCorners[1], vCorners[4]);
-            glNormal3fv(vNormal);
-            glTexCoord2f(0.5f, 1.0f);
-            glVertex3fv(vCorners[0]);
-            glTexCoord2f(0.0f, 0.0f);
-            glVertex3fv(vCorners[1]);
-            glTexCoord2f(1.0f, 0.0f);
-            glVertex3fv(vCorners[4]);
-
-            /* back face */
-            m3dFindNormalf(vNormal, vCorners[0], vCorners[2], vCorners[1]);
-            glNormal3fv(vNormal);
-            glTexCoord2f(0.5f, 1.0f);
-            glVertex3fv(vCorners[0]);
-            glTexCoord2f(0.0f, 0.0f);
-            glVertex3fv(vCorners[2]);
-            glTexCoord2f(1.0f, 0.0f);
-            glVertex3fv(vCorners[1]);
-            
-            /* right face */
-            m3dFindNormalf(vNormal, vCorners[0], vCorners[3], vCorners[2]);
-            glNormal3fv(vNormal);
-            glTexCoord2f(0.5f, 1.0f);
-            glVertex3fv(vCorners[0]);
-            glTexCoord2f(0.0f, 0.0f);
-            glVertex3fv(vCorners[3]);
-            glTexCoord2f(1.0f, 0.0f);
-            glVertex3fv(vCorners[2]);
-        glEnd();
+        glColor3f(1.0f, 1.0f, 1.0f);   
+        gltDrawTriangle();
     
     /* restore the matrix state */
     glPopMatrix();