Experimental support for explicit mip levels

Source/Main.cpp

@@ -41,20 +41,20 @@ const std::map<std::string, std::tuple<std::string, int, vk::Format>> formats =
   {"BC7_SRGB", {"8 bit RGBA - Good general purpose. 16 bytes per block.", 16, vk::Format::eBc7SrgbBlock}}
 };
 
-const std::string usage = "[cube|array] <input> [input2, input3...] <output> <format> [fast|normal|slow|veryslow]";
+const std::string usage = "[cube|array] <input> [input2, input3...] <output> <format> [fast|normal|slow|veryslow] [explicitmips]";
 
 int main(int argc, char ** argv)
 {
   ISPCInit();
 
   if (argc < 4) {
-    std::cout << "Usage: " << argv[0] << " " << usage << std::endl;
+    std::cerr << "Usage: " << argv[0] << " " << usage << std::endl;
-    std::cout << "Formats:" << std::endl;
+    std::cerr << "Formats:" << std::endl;
     for (auto & formatName : formatOrder) {
       auto format = formats.at(formatName);
-      std::cout << "  " << formatName << " - " << std::get<0>(format) << std::endl;
+      std::cerr << "  " << formatName << " - " << std::get<0>(format) << std::endl;
     }
-    return 1;
+    return -1;
   }
 
   int numInputs = argc - 3;
@@ -72,10 +72,19 @@ int main(int argc, char ** argv)
   std::string speedString(argv[argc - 1]);
   std::string formatString;
   int speed = 2;
+  bool explicitmips = false;
+
+  int formatPosition = -1;
+
+  if (speedString == "explicitmips") {
+    speedString = std::string(argv[argc - 2]);
+    numInputs -= 1;
+    explicitmips = true;
+  }
 
   if (speedString == "fast" || speedString == "normal" || speedString == "slow" || speedString == "veryslow") {
-    formatString = std::string(argv[argc - 2]);
     numInputs -= 1;
+    formatPosition -= 1;
 
     if (speedString == "slow") {
       speed = 1;
@@ -86,29 +95,34 @@ int main(int argc, char ** argv)
     } else {
       speed = 2;
     }
-  } else {
-    formatString = std::string(argv[argc - 1]);
   }
 
+  formatString = std::string(argv[argc + formatPosition]);
+
   if (numInputs < 1) {
-    std::cout << "Usage: " << argv[0] << usage << " " << std::endl;
+    std::cerr << "Usage: " << argv[0] << usage << " " << std::endl;
-    return 1;
+    return -1;
   }
 
   if (option == "cube" && numInputs != 6) {
-    std::cout << "Cube maps must have 6 inputs." << std::endl;
+    std::cerr << "Cube maps must have 6 inputs." << std::endl;
-    return 1;
+    return -1;
   }
 
   if (option == "array" && numInputs < 2) {
-    std::cout << "Array maps must have at least 2 inputs." << std::endl;
+    std::cerr << "Array maps must have at least 2 inputs." << std::endl;
-    return 1;
+    return -1;
+  }
+
+  if (option == "array" && explicitmips) {
+    std::cerr << "Explicit mips are not supported for arrays." << std::endl;
+    return -1;
   }
 
   if (formats.find(formatString) == formats.end()) {
-    std::cout << "Invalid format: " << formatString << std::endl;
+    std::cerr << "Invalid format: " << formatString << std::endl;
-    std::cout << usage << std::endl;
+    std::cerr << usage << std::endl;
-    std::cout << "Formats:" << std::endl;
+    std::cerr << "Formats:" << std::endl;
     for (auto & formatName : formatOrder) {
       auto format = formats.at(formatName);
       std::cout << "  " << formatName << " - " << std::get<0>(format) << std::endl;
@@ -190,6 +204,40 @@ int main(int argc, char ** argv)
 
   uint32_t levelCount;
 
+  if (explicitmips) {
+    int levelWidth = 0, levelHeight = 0;
+
+    for (int input = 0; input < numInputs; input++) {
+      std::cout << "Loading/scaling " << input << ": " << inputs[input] << std::endl;      
+
+      if (hdr) {
+        hdrBufferA = stbi_loadf(inputs[input].c_str(), &width, &height, &channels, forcedChannels);
+      } else {
+        ldrBufferA = stbi_load(inputs[input].c_str(), &width, &height, &channels, forcedChannels);
+      }
+
+      if (input == 0) {
+        levelWidth = width;
+        levelHeight = height;
+      } else {
+        if (width != levelWidth || height != levelHeight) {
+          std::cout << "Input " << inputs[input] << " for level " << input << ", dimensions " << width << "x" << height << " do not match expected " << levelWidth << "x" << levelHeight << std::endl;
+          return -1;
+        }
+      }
+
+      if (hdr) {
+        hdrLevels[input].push_back(std::vector<float>(hdrBufferA, hdrBufferA + width * height * forcedChannels));
+        stbi_image_free(hdrBufferA);
+      } else {
+        ldrLevels[input].push_back(std::vector<uint8_t>(ldrBufferA, ldrBufferA + width * height * forcedChannels));
+        stbi_image_free(ldrBufferA);
+      }
+
+      levelWidth = std::max(1, (int)floorf((float)levelWidth / 2));
+      levelHeight = std::max(1, (int)floorf((float)levelHeight / 2));
+    }
+  } else {
     for (int input = 0; input < numInputs; input++) {
       int level = 0;
 
@@ -278,6 +326,7 @@ int main(int argc, char ** argv)
         delete[] ldrBufferB;
       }
     }
+  }
 
   bc6h_enc_settings bc6henc;
   bc7_enc_settings bc7enc;
@@ -401,7 +450,6 @@ int main(int argc, char ** argv)
       level++;
     }
 
-
     /* Compress */
     levelBlocksCompressed[input].resize(levelCount);
     for (unsigned int l = 0; l < levelCount; l++) {