1 files changed, 113 insertions, 0 deletions
diff --git a/system/GLESv2_enc/IOStream2.cpp b/system/GLESv2_enc/IOStream2.cpp
new file mode 100644
index 00000000..1362d3e1
--- /dev/null
+++ b/system/GLESv2_enc/IOStream2.cpp
@@ -0,0 +1,113 @@
+#include "IOStream.h"
+
+#include "GL2Encoder.h"
+
+#include <GLES3/gl31.h>
+
+#include <vector>
+
+#include <assert.h>
+
+void IOStream::readbackPixels(void* context, int width, int height, unsigned int format, unsigned int type, void* pixels) {
+    GL2Encoder *ctx = (GL2Encoder *)context;
+    assert (ctx->state() != NULL);
+
+    int startOffset = 0;
+    int pixelRowSize = 0;
+    int totalRowSize = 0;
+    int skipRows = 0;
+
+    ctx->state()->getPackingOffsets2D(width, height, format, type,
+                                      &startOffset,
+                                      &pixelRowSize,
+                                      &totalRowSize,
+                                      &skipRows);
+
+    size_t pixelDataSize =
+        ctx->state()->pixelDataSize(
+            width, height, 1, format, type, 1 /* is pack */);
+
+    if (startOffset == 0 &&
+        pixelRowSize == totalRowSize) {
+        // fast path
+        readback(pixels, pixelDataSize);
+    } else if (pixelRowSize == totalRowSize) {
+        // fast path but with skip in the beginning
+        std::vector<char> paddingToDiscard(startOffset, 0);
+        readback(&paddingToDiscard[0], startOffset);
+        readback((char*)pixels + startOffset, pixelDataSize - startOffset);
+    } else {
+        int totalReadback = 0;
+
+        if (startOffset > 0) {
+            std::vector<char> paddingToDiscard(startOffset, 0);
+            readback(&paddingToDiscard[0], startOffset);
+            totalReadback += startOffset;
+        }
+        // need to read back row by row
+        size_t paddingSize = totalRowSize - pixelRowSize;
+        std::vector<char> paddingToDiscard(paddingSize, 0);
+
+        char* start = (char*)pixels + startOffset;
+
+        for (int i = 0; i < height; i++) {
+            readback(start, pixelRowSize);
+            totalReadback += pixelRowSize;
+            readback(&paddingToDiscard[0], paddingSize);
+            totalReadback += paddingSize;
+            start += totalRowSize;
+        }
+    }
+}
+
+void IOStream::uploadPixels(void* context, int width, int height, unsigned int format, unsigned int type, const void* pixels) {
+    GL2Encoder *ctx = (GL2Encoder *)context;
+    assert (ctx->state() != NULL);
+
+    int startOffset = 0;
+    int pixelRowSize = 0;
+    int totalRowSize = 0;
+    int skipRows = 0;
+
+    ctx->state()->getUnpackingOffsets2D(width, height, format, type,
+                                        &startOffset,
+                                        &pixelRowSize,
+                                        &totalRowSize,
+                                        &skipRows);
+
+    size_t pixelDataSize =
+        ctx->state()->pixelDataSize(
+            width, height, 1, format, type, 0 /* is unpack */);
+
+    if (startOffset == 0 &&
+        pixelRowSize == totalRowSize) {
+        // fast path
+        writeFully(pixels, pixelDataSize);
+    } else if (pixelRowSize == totalRowSize) {
+        // fast path but with skip in the beginning
+        std::vector<char> paddingToDiscard(startOffset, 0);
+        writeFully(&paddingToDiscard[0], startOffset);
+        writeFully((char*)pixels + startOffset, pixelDataSize - startOffset);
+    } else {
+        int totalReadback = 0;
+
+        if (startOffset > 0) {
+            std::vector<char> paddingToDiscard(startOffset, 0);
+            writeFully(&paddingToDiscard[0], startOffset);
+            totalReadback += startOffset;
+        }
+        // need to upload row by row
+        size_t paddingSize = totalRowSize - pixelRowSize;
+        std::vector<char> paddingToDiscard(paddingSize, 0);
+
+        char* start = (char*)pixels + startOffset;
+
+        for (int i = 0; i < height; i++) {
+            writeFully(start, pixelRowSize);
+            totalReadback += pixelRowSize;
+            writeFully(&paddingToDiscard[0], paddingSize);
+            totalReadback += paddingSize;
+            start += totalRowSize;
+        }
+    }
+}