fg_geometry: GL2 fixed: glDrawElements' indices is byte offset, not element offset

git-svn-id: svn+ssh://svn.code.sf.net/p/freeglut/code/trunk/freeglut/freeglut@1278 7f0cb862-5218-0410-a997-914c9d46530a

diff --git a/src/fg_geometry.c b/src/fg_geometry.c
index 4811ee5..a19e41d 100644 (file)
--- a/src/fg_geometry.c
+++ b/src/fg_geometry.c
@@ -166,7 +166,8 @@ static void fghDrawGeometryWire20(GLfloat *vertices, GLfloat *normals, GLsizei n
     } else {
         fghBindBuffer(FGH_ELEMENT_ARRAY_BUFFER, ibo_elements);
         for (i=0; i<numParts; i++)
-            glDrawElements(vertexMode,numVertPerPart,GL_UNSIGNED_SHORT,(void*)(long)(i*numVertPerPart));
+            glDrawElements(vertexMode, numVertPerPart,
+                           GL_UNSIGNED_SHORT, (GLvoid*)(sizeof(vertIdxs[0])*i*numVertPerPart));
         /* Clean existing bindings before clean-up */
         /* Android showed instability otherwise */
         fghBindBuffer(FGH_ELEMENT_ARRAY_BUFFER, 0);
@@ -174,8 +175,13 @@ static void fghDrawGeometryWire20(GLfloat *vertices, GLfloat *normals, GLsizei n
 
     if (vertIdxs2) {
         fghBindBuffer(FGH_ELEMENT_ARRAY_BUFFER, ibo_elements2);
+        static float t2 = 0;
+        t2 += 0.1;
+        if (t2 >= numParts2)
+            t2 = 0;
         for (i=0; i<numParts2; i++)
-            glDrawElements(GL_LINE_LOOP,numVertPerPart2,GL_UNSIGNED_SHORT,(void*)(long)(i*numVertPerPart2));
+            glDrawElements(GL_LINE_LOOP, numVertPerPart2,
+                           GL_UNSIGNED_SHORT, (GLvoid*)(sizeof(vertIdxs2[0])*i*numVertPerPart2));
         /* Clean existing bindings before clean-up */
         /* Android showed instability otherwise */
         fghBindBuffer(FGH_ELEMENT_ARRAY_BUFFER, 0);
@@ -321,7 +327,7 @@ static void fghDrawGeometrySolid20(GLfloat *vertices, GLfloat *normals, GLushort
         fghBindBuffer(FGH_ELEMENT_ARRAY_BUFFER, ibo_elements);
         if (numParts>1) {
             for (i=0; i<numParts; i++) {
-                glDrawElements(GL_TRIANGLE_STRIP, numVertIdxsPerPart, GL_UNSIGNED_SHORT, (void*)(long)(i*numVertIdxsPerPart));
+                glDrawElements(GL_TRIANGLE_STRIP, numVertIdxsPerPart, GL_UNSIGNED_SHORT, (GLvoid*)(sizeof(vertIdxs[0])*i*numVertIdxsPerPart));
             }
         } else {
             glDrawElements(GL_TRIANGLES, numVertIdxsPerPart, GL_UNSIGNED_SHORT, 0);