Fallback for if ARB_depth_buffer_float is unavailable

aftersomemath · Oct 3, 2023 · b1e6728 · b1e6728
1 parent c6961b7
commit b1e6728
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Showing 2 changed files with 15 additions and 10 deletions.
diff --git a/src/render/render_context.c b/src/render/render_context.c
@@ -1126,11 +1126,13 @@ static void makeOff(mjrContext* con) {
     mju_error("Could not allocate offscreen depth and stencil buffer");
   }
   glBindRenderbuffer(GL_RENDERBUFFER, con->offDepthStencil);
+
+  GLenum depth_buffer_format = mjGLAD_GL_ARB_depth_buffer_float ? GL_DEPTH32F_STENCIL8 : GL_DEPTH24_STENCIL8;
   if (con->offSamples) {
-    glRenderbufferStorageMultisample(GL_RENDERBUFFER, con->offSamples, GL_DEPTH32F_STENCIL8,
+    glRenderbufferStorageMultisample(GL_RENDERBUFFER, con->offSamples, depth_buffer_format,
                                      con->offWidth, con->offHeight);
   } else {
-    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH32F_STENCIL8, con->offWidth, con->offHeight);
+    glRenderbufferStorage(GL_RENDERBUFFER, depth_buffer_format, con->offWidth, con->offHeight);
   }
   glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
                             GL_RENDERBUFFER, con->offDepthStencil);
@@ -1169,7 +1171,7 @@ static void makeOff(mjrContext* con) {
       mju_error("Could not allocate offscreen depth and stencil buffer_r");
     }
     glBindRenderbuffer(GL_RENDERBUFFER, con->offDepthStencil_r);
-    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH32F_STENCIL8, con->offWidth, con->offHeight);
+    glRenderbufferStorage(GL_RENDERBUFFER, depth_buffer_format, con->offWidth, con->offHeight);
     glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
                               GL_RENDERBUFFER, con->offDepthStencil_r);
 
@@ -1489,9 +1491,6 @@ void mjr_makeContext_offSize(const mjModel* m, mjrContext* con, int fontscale,
     if (!mjGLAD_GL_ARB_vertex_buffer_object) {
       mju_error("OpenGL ARB_vertex_buffer_object required");
     }
-    if (!mjGLAD_GL_ARB_depth_buffer_float) {
-      mju_error("OpenGL ARB_depth_buffer_float required");
-    }
     con->glInitialized = 1;
 
     // determine window availability (could be EGL-headless)

diff --git a/src/render/render_gl2.c b/src/render/render_gl2.c
@@ -119,8 +119,11 @@ void mjr_readPixels(unsigned char* rgb, float* depth,
         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
       }
-      else if (!mjGLAD_GL_ARB_clip_control) {
-        mju_warning("ARB_clip_control unavailable while mjDEPTH_ZEROFAR requested, depth accuracy will be limited");
+      if (con->readDepthMap == mjDEPTH_ZEROFAR && !mjGLAD_GL_ARB_clip_control) {
+        mju_warning("mjDEPTH_ZEROFAR requested but ARB_clip_control unavailable, depth accuracy will be limited");
+      }
+      if (con->readDepthMap == mjDEPTH_ZEROFAR) {
+        mju_warning("mjDEPTH_ZEROFAR requested but window depth buffer precision may be limited");
       }
     }
   }
@@ -170,8 +173,11 @@ void mjr_readPixels(unsigned char* rgb, float* depth,
         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
       }
-      else if (!mjGLAD_GL_ARB_clip_control) {
-        mju_warning("ARB_clip_control unavailable while mjDEPTH_ZEROFAR requested, depth accuracy will be limited");
+      if (con->readDepthMap == mjDEPTH_ZEROFAR && !mjGLAD_GL_ARB_clip_control) {
+        mju_warning("mjDEPTH_ZEROFAR requested but ARB_clip_control unavailable, depth accuracy will be limited");
+      }
+      if (con->readDepthMap == mjDEPTH_ZEROFAR && !mjGLAD_GL_ARB_depth_buffer_float) {
+        mju_warning("mjDEPTH_ZEROFAR requested but ARB_depth_buffer_float unavailable, depth accuracy will be limited");
       }
     }