texture: Fix get_ram_image_as() with 3D and multiview textures

Fixes #1277

panda/src/gobj/texture.cxx

@@ -1072,13 +1072,13 @@ set_ram_image_as(CPTA_uchar image, const string &supplied_format) {
     if (format == "A" && cdata->_num_components != 3) {
       // We can generally rely on alpha to be the last component.
       int component = cdata->_num_components - 1;
-      for (int p = 0; p < imgsize; ++p) {
+      for (size_t p = 0; p < imgsize; ++p) {
         newdata[component] = image[p];
       }
       do_set_ram_image(cdata, newdata);
       return;
     }
-    for (int p = 0; p < imgsize; ++p) {
+    for (size_t p = 0; p < imgsize; ++p) {
       for (uchar s = 0; s < format.size(); ++s) {
         signed char component = -1;
         if (format.at(s) == 'B' || (cdata->_num_components <= 2 && format.at(s) != 'A')) {
@@ -1110,7 +1110,7 @@ set_ram_image_as(CPTA_uchar image, const string &supplied_format) {
     do_set_ram_image(cdata, newdata);
     return;
   }
-  for (int p = 0; p < imgsize; ++p) {
+  for (size_t p = 0; p < imgsize; ++p) {
     for (uchar s = 0; s < format.size(); ++s) {
       signed char component = -1;
       if (format.at(s) == 'B' || (cdata->_num_components <= 2 && format.at(s) != 'A')) {
@@ -7405,7 +7405,8 @@ get_ram_image_as(const string &requested_format) {
     gobj_cat.error() << "Couldn't find an uncompressed RAM image!\n";
     return CPTA_uchar(get_class_type());
   }
-  int imgsize = cdata->_x_size * cdata->_y_size;
+  size_t imgsize = (size_t)cdata->_x_size * (size_t)cdata->_y_size *
+                   (size_t)cdata->_z_size * (size_t)cdata->_num_views;
   nassertr(cdata->_num_components > 0 && cdata->_num_components <= 4, CPTA_uchar(get_class_type()));
   nassertr(data.size() == (size_t)(cdata->_component_width * cdata->_num_components * imgsize), CPTA_uchar(get_class_type()));
 
@@ -7443,7 +7444,7 @@ get_ram_image_as(const string &requested_format) {
       const uint32_t *src = (const uint32_t *)data.p();
       uint32_t *dst = (uint32_t *)newdata.p();
 
-      for (int p = 0; p < imgsize; ++p) {
+      for (size_t p = 0; p < imgsize; ++p) {
         uint32_t v = *src++;
         *dst++ = ((v & 0xff00ff00u)) |
                  ((v & 0x00ff0000u) >> 16) |
@@ -7530,14 +7531,14 @@ get_ram_image_as(const string &requested_format) {
     }
     if (format == "A" && cdata->_num_components != 3) {
       // We can generally rely on alpha to be the last component.
-      for (int p = 0; p < imgsize; ++p) {
+      for (size_t p = 0; p < imgsize; ++p) {
         dst[p] = src[alpha];
         src += cdata->_num_components;
       }
       return newdata;
     }
     // Fallback case for other 8-bit-per-channel formats.
-    for (int p = 0; p < imgsize; ++p) {
+    for (size_t p = 0; p < imgsize; ++p) {
       for (size_t i = 0; i < format.size(); ++i) {
         if (format[i] == 'B' || (cdata->_num_components <= 2 && format[i] != 'A')) {
           *dst++ = src[0];
@@ -7563,7 +7564,7 @@ get_ram_image_as(const string &requested_format) {
   }
 
   // The slow and general case.
-  for (int p = 0; p < imgsize; ++p) {
+  for (size_t p = 0; p < imgsize; ++p) {
     for (size_t i = 0; i < format.size(); ++i) {
       int component = 0;
       if (format[i] == 'B' || (cdata->_num_components <= 2 && format[i] != 'A')) {