Move texture upload behavior to TextureState

Change-Id: If1cb32bbc04f437fa0d079084de832de9fd777c2
diff --git a/libs/hwui/renderstate/TextureState.cpp b/libs/hwui/renderstate/TextureState.cpp
index 987d4cd..1f50f71 100644
--- a/libs/hwui/renderstate/TextureState.cpp
+++ b/libs/hwui/renderstate/TextureState.cpp
@@ -15,6 +15,14 @@
  */
 #include "renderstate/TextureState.h"
 
+#include "Caches.h"
+#include "utils/TraceUtils.h"
+
+#include <GLES3/gl3.h>
+#include <memory>
+#include <SkCanvas.h>
+#include <SkBitmap.h>
+
 namespace android {
 namespace uirenderer {
 
@@ -26,6 +34,134 @@
     GL_TEXTURE3
 };
 
+static void uploadToTexture(bool resize, GLenum format, GLenum type, GLsizei stride, GLsizei bpp,
+        GLsizei width, GLsizei height, const GLvoid * data) {
+
+    glPixelStorei(GL_UNPACK_ALIGNMENT, bpp);
+    const bool useStride = stride != width
+            && Caches::getInstance().extensions().hasUnpackRowLength();
+    if ((stride == width) || useStride) {
+        if (useStride) {
+            glPixelStorei(GL_UNPACK_ROW_LENGTH, stride);
+        }
+
+        if (resize) {
+            glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, type, data);
+        } else {
+            glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, type, data);
+        }
+
+        if (useStride) {
+            glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
+        }
+    } else {
+        //  With OpenGL ES 2.0 we need to copy the bitmap in a temporary buffer
+        //  if the stride doesn't match the width
+
+        GLvoid * temp = (GLvoid *) malloc(width * height * bpp);
+        if (!temp) return;
+
+        uint8_t * pDst = (uint8_t *)temp;
+        uint8_t * pSrc = (uint8_t *)data;
+        for (GLsizei i = 0; i < height; i++) {
+            memcpy(pDst, pSrc, width * bpp);
+            pDst += width * bpp;
+            pSrc += stride * bpp;
+        }
+
+        if (resize) {
+            glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, type, temp);
+        } else {
+            glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, type, temp);
+        }
+
+        free(temp);
+    }
+}
+
+static void uploadSkBitmapToTexture(const SkBitmap& bitmap,
+        bool resize, GLenum format, GLenum type) {
+    uploadToTexture(resize, format, type, bitmap.rowBytesAsPixels(), bitmap.bytesPerPixel(),
+            bitmap.width(), bitmap.height(), bitmap.getPixels());
+}
+
+void TextureState::generateTexture(const SkBitmap* bitmap, Texture* texture, bool regenerate) {
+    SkAutoLockPixels alp(*bitmap);
+
+    if (!bitmap->readyToDraw()) {
+        ALOGE("Cannot generate texture from bitmap");
+        return;
+    }
+
+    ATRACE_FORMAT("Upload %ux%u Texture", bitmap->width(), bitmap->height());
+
+    // We could also enable mipmapping if both bitmap dimensions are powers
+    // of 2 but we'd have to deal with size changes. Let's keep this simple
+    const bool canMipMap = Caches::getInstance().extensions().hasNPot();
+
+    // If the texture had mipmap enabled but not anymore,
+    // force a glTexImage2D to discard the mipmap levels
+    const bool resize = !regenerate || bitmap->width() != int(texture->width) ||
+            bitmap->height() != int(texture->height) ||
+            (regenerate && canMipMap && texture->mipMap && !bitmap->hasHardwareMipMap());
+
+    if (!regenerate) {
+        glGenTextures(1, &texture->id);
+    }
+
+    texture->generation = bitmap->getGenerationID();
+    texture->width = bitmap->width();
+    texture->height = bitmap->height();
+
+    bindTexture(texture->id);
+
+    switch (bitmap->colorType()) {
+    case kAlpha_8_SkColorType:
+        uploadSkBitmapToTexture(*bitmap, resize, GL_ALPHA, GL_UNSIGNED_BYTE);
+        texture->blend = true;
+        break;
+    case kRGB_565_SkColorType:
+        uploadSkBitmapToTexture(*bitmap, resize, GL_RGB, GL_UNSIGNED_SHORT_5_6_5);
+        texture->blend = false;
+        break;
+    case kN32_SkColorType:
+        uploadSkBitmapToTexture(*bitmap, resize, GL_RGBA, GL_UNSIGNED_BYTE);
+        // Do this after calling getPixels() to make sure Skia's deferred
+        // decoding happened
+        texture->blend = !bitmap->isOpaque();
+        break;
+    case kARGB_4444_SkColorType:
+    case kIndex_8_SkColorType: {
+        SkBitmap rgbaBitmap;
+        rgbaBitmap.allocPixels(SkImageInfo::MakeN32(texture->width, texture->height,
+                bitmap->alphaType()));
+        rgbaBitmap.eraseColor(0);
+
+        SkCanvas canvas(rgbaBitmap);
+        canvas.drawBitmap(*bitmap, 0.0f, 0.0f, nullptr);
+
+        uploadSkBitmapToTexture(rgbaBitmap, resize, GL_RGBA, GL_UNSIGNED_BYTE);
+        texture->blend = !bitmap->isOpaque();
+        break;
+    }
+    default:
+        ALOGW("Unsupported bitmap colorType: %d", bitmap->colorType());
+        break;
+    }
+
+    if (canMipMap) {
+        texture->mipMap = bitmap->hasHardwareMipMap();
+        if (texture->mipMap) {
+            glGenerateMipmap(GL_TEXTURE_2D);
+        }
+    }
+
+    if (!regenerate) {
+        texture->setFilter(GL_NEAREST);
+        texture->setWrap(GL_CLAMP_TO_EDGE);
+    }
+}
+
 TextureState::TextureState()
         : mTextureUnit(0) {
     glActiveTexture(kTextureUnits[0]);