backend updates

pd-3ds:
Add support for RGB565 textures
pd-desktop:
Add support for A8 textures
Add glfw callback chain to not break other libs using the same callback

backends/3ds/source/bknd-gfx.cpp

@@ -95,6 +95,11 @@ void FragCfg(GPU_TEXCOLOR clr) {
       C3D_TexEnvFunc(env, C3D_RGB, GPU_REPLACE);
       C3D_TexEnvFunc(env, C3D_Alpha, GPU_MODULATE);
       break;
+    case GPU_RGB565:
+      C3D_TexEnvSrc(env, C3D_Alpha, GPU_TEXTURE0);
+      C3D_TexEnvFunc(env, C3D_RGB, GPU_MODULATE);
+      C3D_TexEnvFunc(env, C3D_Alpha, GPU_REPLACE);
+      break;
 
     default:
       C3D_TexEnvSrc(env, C3D_Both, GPU_TEXTURE0);

backends/desktop/include/pd-desktop/bknd-gfx.hpp

@@ -57,6 +57,7 @@ class GfxGL2 : public GfxDriver {
   GLuint Shader;
   GLuint pLocProjection;
   GLuint pLocTex;
+  GLuint pLocAlfa;
   GLuint VBO, IBO;
 };
 }  // namespace PD

backends/desktop/include/pd-desktop/bknd-hid.hpp

@@ -64,6 +64,7 @@ class HidGLFW : public HidDriver {
   GLFWwindow* Window;
   int PrevState;
   std::unordered_map<int, int> PrevStates;
+  static GLFWcharfun pOldTextCB;
   static std::string* pText;
   bool pInTextMode = false;
   PD::u64 pLastUpdate = 0;

backends/desktop/source/bknd-gfx.cpp

@@ -53,10 +53,15 @@ const char* frag_shader = R"(
   varying vec4 oColor;
   
   uniform sampler2D tex;
+  uniform bool alfa;
       
   void main() {
-      vec4 tc = texture2D(tex, oUV);
-      gl_FragColor = tc*oColor;
+    vec4 tc = texture2D(tex, oUV);
+    if (alfa) {
+      gl_FragColor = vec4(oColor.rgb, tc.a * oColor.a);
+    } else {
+      gl_FragColor = tc * oColor;
+    }
   }
   )";
 
@@ -138,6 +143,7 @@ void GfxGL2::Init() {
   glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IBO);
 
   pLocTex = glGetUniformLocation(Shader, "tex");
+  pLocAlfa = glGetUniformLocation(Shader, "alfa");
   pLocProjection = glGetUniformLocation(Shader, "projection");
 
   glBindBuffer(GL_ARRAY_BUFFER, 0);
@@ -172,6 +178,9 @@ void GfxGL2::BindTex(PD::Li::TexAddress addr) {
   glActiveTexture(GL_TEXTURE0);
   glBindTexture(GL_TEXTURE_2D, (GLuint)addr);
   glUniform1i(pLocTex, 0);
+  GLint fmt = 0;
+  glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_INTERNAL_FORMAT, &fmt);
+  glUniform1i(pLocAlfa, fmt == GL_ALPHA);
 }
 
 void GfxGL2::RenderDrawData(const std::vector<PD::Li::Command::Ref>& Commands) {

backends/desktop/source/bknd-hid.cpp

@@ -24,11 +24,21 @@ SOFTWARE.
 
 #include <pd-desktop/bknd-hid.hpp>
 namespace PD {
-std::string* HidGLFW::pText;
+std::string* HidGLFW::pText = nullptr;
+GLFWcharfun HidGLFW::pOldTextCB = nullptr;
 // Default Call back (If no Text input is requsted)
-void NullTextCB(GLFWwindow* win, unsigned int c) {}
+void NullTextCB(GLFWwindow* win, unsigned int c) {
+  // Chain
+  if (HidGLFW::pOldTextCB) {
+    HidGLFW::pOldTextCB(win, c);
+  }
+}
 // Text callback if requested
 void TextCB(GLFWwindow* win, unsigned int c) {
+  // Chain
+  if (HidGLFW::pOldTextCB) {
+    HidGLFW::pOldTextCB(win, c);
+  }
   if (!HidGLFW::pText) {
     return;
   }
@@ -36,7 +46,7 @@ void TextCB(GLFWwindow* win, unsigned int c) {
 }
 HidGLFW::HidGLFW(GLFWwindow* win) : HidDriver("HidGLFW") {
   Window = win;
-  glfwSetCharCallback(Window, NullTextCB);
+  HidGLFW::pOldTextCB = glfwSetCharCallback(Window, NullTextCB);
   Flags |= Flags_HasKeyboard;
   Flags |= Flags_HasMouse;
   pBinds[GLFW_MOUSE_BUTTON_LEFT] = Touch;