[core] convert LineAtlas to use managed texture handling

2 files changed, 30 insertions, 66 deletions

diff --git a/src/mbgl/geometry/line_atlas.cpp b/src/mbgl/geometry/line_atlas.cpp
index 50e82cc015..5e11fe5c49 100644
--- a/src/mbgl/geometry/line_atlas.cpp
+++ b/src/mbgl/geometry/line_atlas.cpp
@@ -11,10 +11,8 @@
 
 namespace mbgl {
 
-LineAtlas::LineAtlas(uint16_t w, uint16_t h)
-    : width(w),
-      height(h),
-      data(std::make_unique<char[]>(w * h)),
+LineAtlas::LineAtlas(const Size size)
+    : image(size),
       dirty(true) {
 }
 
@@ -40,11 +38,11 @@ LinePatternPos LineAtlas::getDashPosition(const std::vector<float>& dasharray,
 }
 
 LinePatternPos LineAtlas::addDash(const std::vector<float>& dasharray, LinePatternCap patternCap) {
-    int n = patternCap == LinePatternCap::Round ? 7 : 0;
-    int dashheight = 2 * n + 1;
+    const uint8_t n = patternCap == LinePatternCap::Round ? 7 : 0;
+    const uint8_t dashheight = 2 * n + 1;
     const uint8_t offset = 128;
 
-    if (nextRow + dashheight > height) {
+    if (nextRow + dashheight > image.size.height) {
         Log::Warning(Event::OpenGL, "line atlas bitmap overflow");
         return LinePatternPos();
     }
@@ -54,7 +52,7 @@ LinePatternPos LineAtlas::addDash(const std::vector<float>& dasharray, LinePatte
         length += part;
     }
 
-    float stretch = width / length;
+    float stretch = image.size.width / length;
     float halfWidth = stretch * 0.5;
     // If dasharray has an odd length, both the first and last parts
     // are dashes and should be joined seamlessly.
@@ -62,7 +60,7 @@ LinePatternPos LineAtlas::addDash(const std::vector<float>& dasharray, LinePatte
 
     for (int y = -n; y <= n; y++) {
         int row = nextRow + n + y;
-        int index = width * row;
+        int index = image.size.width * row;
 
         float left = 0;
         float right = dasharray[0];
@@ -72,7 +70,7 @@ LinePatternPos LineAtlas::addDash(const std::vector<float>& dasharray, LinePatte
             left -= dasharray.back();
         }
 
-        for (int x = 0; x < width; x++) {
+        for (uint32_t x = 0; x < image.size.width; x++) {
 
             while (right < x / stretch) {
                 left = right;
@@ -104,13 +102,13 @@ LinePatternPos LineAtlas::addDash(const std::vector<float>& dasharray, LinePatte
                 signedDistance = int((inside ? 1 : -1) * dist);
             }
 
-            data[index + x] = fmax(0, fmin(255, signedDistance + offset));
+            image.data[index + x] = fmax(0, fmin(255, signedDistance + offset));
         }
     }
 
     LinePatternPos position;
-    position.y = (0.5 + nextRow + n) / height;
-    position.height = (2.0 * n) / height;
+    position.y = (0.5 + nextRow + n) / image.size.height;
+    position.height = (2.0 * n) / image.size.height;
     position.width = length;
 
     nextRow += dashheight;
@@ -120,59 +118,24 @@ LinePatternPos LineAtlas::addDash(const std::vector<float>& dasharray, LinePatte
     return position;
 }
 
-void LineAtlas::upload(gl::Context& context, gl::TextureUnit unit) {
-    if (dirty) {
-        bind(context, unit);
-    }
+Size LineAtlas::getSize() const {
+    return image.size;
 }
 
-void LineAtlas::bind(gl::Context& context, gl::TextureUnit unit) {
-    bool first = false;
+void LineAtlas::upload(gl::Context& context, gl::TextureUnit unit) {
     if (!texture) {
-        texture = context.createTexture();
-        context.activeTexture = unit;
-        context.texture[unit] = *texture;
-        MBGL_CHECK_ERROR(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
-        MBGL_CHECK_ERROR(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
-        MBGL_CHECK_ERROR(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT));
-        MBGL_CHECK_ERROR(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE));
-        first = true;
-    } else if (context.texture[unit] != *texture) {
-        context.activeTexture = unit;
-        context.texture[unit] = *texture;
+        texture = context.createTexture(image, unit);
+    } else if (dirty) {
+        context.updateTexture(*texture, image, unit);
     }
 
-    if (dirty) {
-        context.activeTexture = unit;
-        if (first) {
-            MBGL_CHECK_ERROR(glTexImage2D(
-                GL_TEXTURE_2D, // GLenum target
-                0, // GLint level
-                GL_ALPHA, // GLint internalformat
-                width, // GLsizei width
-                height, // GLsizei height
-                0, // GLint border
-                GL_ALPHA, // GLenum format
-                GL_UNSIGNED_BYTE, // GLenum type
-                data.get() // const GLvoid * data
-            ));
-        } else {
-            MBGL_CHECK_ERROR(glTexSubImage2D(
-                GL_TEXTURE_2D, // GLenum target
-                0, // GLint level
-                0, // GLint xoffset
-                0, // GLint yoffset
-                width, // GLsizei width
-                height, // GLsizei height
-                GL_ALPHA, // GLenum format
-                GL_UNSIGNED_BYTE, // GLenum type
-                data.get() // const GLvoid *pixels
-            ));
-        }
-
+    dirty = false;
+}
 
-        dirty = false;
-    }
+void LineAtlas::bind(gl::Context& context, gl::TextureUnit unit) {
+    upload(context, unit);
+    context.bindTexture(*texture, unit, gl::TextureFilter::Linear, gl::TextureMipMap::No,
+                        gl::TextureWrap::Repeat, gl::TextureWrap::Clamp);
 }
 
 } // namespace mbgl
diff --git a/src/mbgl/geometry/line_atlas.hpp b/src/mbgl/geometry/line_atlas.hpp
index 66a2343a42..b1e7a670c1 100644
--- a/src/mbgl/geometry/line_atlas.hpp
+++ b/src/mbgl/geometry/line_atlas.hpp
@@ -1,6 +1,8 @@
 #pragma once
 
+#include <mbgl/gl/texture.hpp>
 #include <mbgl/gl/object.hpp>
+#include <mbgl/util/image.hpp>
 #include <mbgl/util/optional.hpp>
 
 #include <vector>
@@ -27,7 +29,7 @@ enum class LinePatternCap : bool {
 
 class LineAtlas {
 public:
-    LineAtlas(uint16_t width, uint16_t height);
+    LineAtlas(Size);
     ~LineAtlas();
 
     // Binds the atlas texture to the GPU, and uploads data if it is out of date.
@@ -40,14 +42,13 @@ public:
     LinePatternPos getDashPosition(const std::vector<float>&, LinePatternCap);
     LinePatternPos addDash(const std::vector<float>& dasharray, LinePatternCap);
 
-    const uint16_t width;
-    const uint16_t height;
+    Size getSize() const;
 
 private:
-    const std::unique_ptr<char[]> data;
+    const AlphaImage image;
     bool dirty;
-    mbgl::optional<gl::UniqueTexture> texture;
-    int nextRow = 0;
+    mbgl::optional<gl::Texture> texture;
+    uint32_t nextRow = 0;
     std::unordered_map<size_t, LinePatternPos> positions;
 };