Fix blit shader in Android

Author: floppyhammer

demo/android/app/src/main/cpp/native_engine.cpp

@@ -67,7 +67,7 @@ void NativeEngine::init_app_common(Pathfinder::Vec2I window_size) {
     // Create app.
     pf_app = std::make_shared<App>(pf_device, pf_queue, window_size, svg_input, img_input);
 
-    pf_blit = std::make_shared<Blit>(pf_device, pf_queue, pf_swapchain->get_surface_format());
+    pf_blit = std::make_shared<Pathfinder::Blit>(pf_device, pf_queue, pf_swapchain->get_surface_format());
 
     auto dst_texture = pf_device->create_texture({window_size, Pathfinder::TextureFormat::Rgba8Unorm}, "dst texture");
 

demo/android/app/src/main/cpp/native_engine.h

@@ -26,7 +26,7 @@ class NativeEngine {
     android_app *mAppCtx;
 
     std::shared_ptr<App> pf_app;
-    std::shared_ptr<Blit> pf_blit;
+    std::shared_ptr<Pathfinder::Blit> pf_blit;
 
     std::shared_ptr<Pathfinder::WindowBuilder> window_builder;
     std::shared_ptr<Pathfinder::Window> pf_window;

pathfinder/gpu/gl/shader_module.cpp

@@ -13,7 +13,7 @@
 
 namespace Pathfinder {
 
-bool replace(std::string &str, const std::string &from, const std::string &to) {
+bool replaceFirst(std::string &str, const std::string &from, const std::string &to) {
     size_t start_pos = str.find(from);
     if (start_pos == std::string::npos) {
         return false;
@@ -22,6 +22,15 @@ bool replace(std::string &str, const std::string &from, const std::string &to) {
     return true;
 }
 
+void replaceAll(std::string &str, const std::string &from, const std::string &to) {
+    if (from.empty()) return;
+    size_t start_pos = 0;
+    while ((start_pos = str.find(from, start_pos)) != std::string::npos) {
+        str.replace(start_pos, from.length(), to);
+        start_pos += to.length();
+    }
+}
+
 ShaderModuleGl::ShaderModuleGl(const std::vector<char> &source_code,
                                ShaderStage shader_stage,
                                const std::string &label) {
@@ -48,9 +57,22 @@ ShaderModuleGl::ShaderModuleGl(const std::vector<char> &source_code,
 
 #ifdef PATHFINDER_MINIMUM_SHADER_VERSION_SUPPORT
     if (shader_stage == ShaderStage::Compute) {
-        replace(code_string, "#version 430", "#version 310 es");
+        replaceFirst(code_string, "#version 430", "#version 310 es");
     } else {
-        replace(code_string, "#version 310 es", "#version 300 es");
+        replaceFirst(code_string, "#version 310 es", "#version 300 es");
+    }
+
+    if (shader_stage == ShaderStage::Vertex) {
+        // 1. Find where "#version" is
+        size_t ver_pos = code_string.find("#version");
+        if (ver_pos != std::string::npos) {
+            // 2. Find the following line break
+            size_t nl_pos = code_string.find('\n', ver_pos);
+            if (nl_pos != std::string::npos) {
+                // 3. Add a new line
+                code_string.insert(nl_pos + 1, "#define gl_VertexIndex gl_VertexID\n");
+            }
+        }
     }
 #endif
 

pathfinder/gpu/gl/swap_chain.cpp

@@ -17,7 +17,7 @@ SwapChainGl::SwapChainGl(Vec2I size, EGLDisplay egl_display, EGLSurface egl_surf
     : SwapChain(size) {
     command_encoder_ = std::shared_ptr<CommandEncoderGl>(new CommandEncoderGl());
 
-    render_pass_ = std::shared_ptr<RenderPassGl>(new RenderPassGl(AttachmentLoadOp::Clear));
+    render_pass_ = std::shared_ptr<RenderPassGl>(new RenderPassGl(AttachmentLoadOp::Clear, "Swapchain Render Pass"));
 
     egl_display_ = egl_display;
     egl_surface_ = egl_surface;