Fixups to comments and flags for reversed Z rendering

src/render/render_context.c

@@ -1614,7 +1614,7 @@ void mjr_makeContext_offSize(const mjModel* m, mjrContext* con, int fontscale,
   con->readPixelFormat = GL_RGB;
 
   // set default depth mapping for mjr_readPixels
-  con->readDepthMapping = mjDM_ZEROTOONE;
+  con->readDepthMap = mjDEPTHMAP_01;
 }
 
 
@@ -1836,7 +1836,6 @@ MJAPI void mjr_resizeOffscreen(int width, int height, mjrContext* con) {
     glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, con->offWidth, con->offHeight);
   }
 
-
   glBindRenderbuffer(GL_RENDERBUFFER, con->offDepthStencil);
   if (con->offSamples) {
     glRenderbufferStorageMultisample(GL_RENDERBUFFER, con->offSamples, GL_DEPTH32F_STENCIL8,

src/render/render_gl2.c

@@ -115,7 +115,7 @@ void mjr_readPixels(unsigned char* rgb, float* depth,
     if (depth) {
       glReadPixels(viewport.left, viewport.bottom, viewport.width, viewport.height,
                    GL_DEPTH_COMPONENT, GL_FLOAT, depth);
-      if (con->readDepthMapping == mjDM_ZEROTOONE) {
+      if (con->readDepthMap == mjDEPTHMAP_01) {
         int N_pixels = viewport.width * viewport.height;
         for (int i = 0; i < N_pixels; i++) depth[i] = 1.0 - depth[i]; // Reverse the reversed Z buffer
       }
@@ -164,7 +164,7 @@ void mjr_readPixels(unsigned char* rgb, float* depth,
       glReadPixels(viewport.left, viewport.bottom, viewport.width, viewport.height,
                    GL_DEPTH_COMPONENT, GL_FLOAT, depth);
 
-      if (con->readDepthMapping == mjDM_ZEROTOONE) {
+      if (con->readDepthMap == mjDEPTHMAP_01) {
         int N_pixels = viewport.width * viewport.height;
         for (int i = 0; i < N_pixels; i++) depth[i] = 1.0 - depth[i]; // Reverse the reversed Z buffer
       }

src/render/render_gl3.c

@@ -601,9 +601,9 @@ static void setView(int view, mjrRect viewport, const mjvScene* scn, const mjrCo
   // set projection
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
-  // reverse Z rendering mapping (znear, zfar) -> (1, 0)
-  glTranslatef(0,0,0.5);
-  glScalef(1,1,-0.5);
+  // reverse Z rendering mapping [znear, zfar] -> [1, 0]
+  glTranslatef(0.0f, 0.0f, 0.5f);
+  glScalef(1.0f, 1.0f, -0.5f);
   glFrustum(cam.frustum_center - halfwidth,
             cam.frustum_center + halfwidth,
             cam.frustum_bottom,
@@ -682,7 +682,6 @@ void mjr_render(mjrRect viewport, mjvScene* scn, const mjrContext* con) {
     0.0f, 0.0f, 1.0f, 0.0f,
     0.5f, 0.5f, 0.0f, 1.0f
   };
-
   float tempMatrix[16], textureMatrix[16];
   mjvGeom *thisgeom, tempgeom;
   mjvLight *thislight;
@@ -1030,9 +1029,9 @@ void mjr_render(mjrRect viewport, mjvScene* scn, const mjrContext* con) {
           // set projection: from light viewpoint
           glMatrixMode(GL_PROJECTION);
           glLoadIdentity();
-          // reverse Z rendering mapping (znear, zfar) -> (1, 0)
-          glTranslatef(0,0,0.5);
-          glScalef(1,1,-0.5);
+          // reverse Z rendering mapping [znear, zfar] -> [1, 0]
+          glTranslatef(0.0f, 0.0f, 0.5f);
+          glScalef(1.0f , 1.0f, -0.5f);
           if (thislight->directional) {
             glOrtho(-con->shadowClip, con->shadowClip,
                     -con->shadowClip, con->shadowClip,