From 21a46ee15141d2c84f6a392afbd6db61c3c29582 Mon Sep 17 00:00:00 2001
From: Swung0x48 <swung0x48@outlook.com>
Date: Mon, 11 Aug 2025 16:47:18 +0800
Subject: [PATCH] [Feat] (MG_State/Program): glShaderSource, glUseProgram

---
 .../MG_Impl/GLImpl/Program/GL_Program.cpp     | 29 +++++++++++++++++--
 MobileGL/MG_State/GLState/Core.cpp            |  4 +++
 MobileGL/MG_State/GLState/Core.h              |  1 +
 .../GLState/ProgramState/ProgramState.cpp     |  8 +++++
 .../GLState/ProgramState/ProgramState.h       |  4 +++
 .../GLState/ProgramState/ShaderObject.cpp     |  4 +++
 .../GLState/ProgramState/ShaderObject.h       |  1 +
 7 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/MobileGL/MG_Impl/GLImpl/Program/GL_Program.cpp b/MobileGL/MG_Impl/GLImpl/Program/GL_Program.cpp
index d65a1db5..0e7cea03 100644
--- a/MobileGL/MG_Impl/GLImpl/Program/GL_Program.cpp
+++ b/MobileGL/MG_Impl/GLImpl/Program/GL_Program.cpp
@@ -203,11 +203,36 @@ namespace MobileGL {
         }
 
         void ShaderSource_State(GLuint shader, GLsizei count, const GLchar* const* string, const GLint* length) {
-            THROW_UNIMPL_EXCEPTION;
+            if (count < 0) {
+                MG_State::pGLContext->RecordError(
+                    ErrorCode::InvalidValue,
+                    MakeShared<GenericErrorInfo>("MG_Impl/GLImpl", __func__,
+                                             "`count` is less than 0."));
+            }
+
+            auto programObject = TryToGetShaderObject(shader);
+            if (!programObject)
+                return;
+
+            std::string src;
+            for (GLsizei i = 0; i < count; i++) {
+                src +=
+                    (length[i] <= 0) ? string[i] : std::string(string[i], length[i]);
+            }
+            programObject->SetShaderSource(Move(src));
         }
 
         void UseProgram_State(GLuint program) {
-            THROW_UNIMPL_EXCEPTION;
+            if (program == 0) {
+                MG_State::pGLContext->UseProgram(0);
+                return;
+            }
+
+            auto programObject = TryToGetProgramObject(program);
+            if (!programObject)
+                return;
+            MG_State::pGLContext->UseProgram(program);
+
         }
 
         void Uniform1f_State(GLint location, GLfloat v0) {
diff --git a/MobileGL/MG_State/GLState/Core.cpp b/MobileGL/MG_State/GLState/Core.cpp
index 92c190ea..3f28f6f4 100644
--- a/MobileGL/MG_State/GLState/Core.cpp
+++ b/MobileGL/MG_State/GLState/Core.cpp
@@ -187,6 +187,10 @@ namespace MobileGL {
             SharedPtr<ShaderObject> GLContext::GetShaderObject(const Uint index) {
                 return m_programState.GetShaderObject(index);
             }
+
+            void GLContext::UseProgram(Uint program) {
+                return m_programState.UseProgram(program);
+            }
         } // namespace GLState
 
         GLState::GLContext* pGLContext;
diff --git a/MobileGL/MG_State/GLState/Core.h b/MobileGL/MG_State/GLState/Core.h
index b3bb10c6..e57d0785 100644
--- a/MobileGL/MG_State/GLState/Core.h
+++ b/MobileGL/MG_State/GLState/Core.h
@@ -63,6 +63,7 @@ namespace MobileGL {
                 Bool ValidateShaderName(Uint index) const;
                 SharedPtr<ProgramObject> GetProgramObject(Uint index);
                 SharedPtr<ShaderObject> GetShaderObject(Uint index);
+                void UseProgram(Uint program);
             private:
                 // Error
                 ErrorState m_errorState;
diff --git a/MobileGL/MG_State/GLState/ProgramState/ProgramState.cpp b/MobileGL/MG_State/GLState/ProgramState/ProgramState.cpp
index a90a9457..6f290128 100644
--- a/MobileGL/MG_State/GLState/ProgramState/ProgramState.cpp
+++ b/MobileGL/MG_State/GLState/ProgramState/ProgramState.cpp
@@ -33,6 +33,14 @@ namespace MobileGL {
                 return CheckIndexAvail(program, m_programObjects) && m_programObjects[program] != nullptr;
             }
 
+            void ProgramState::UseProgram(Uint program) {
+                if (program == 0)
+                    m_currentProgram.reset();
+
+                if (!CheckIndexAvail(program, m_programObjects)) return;
+                m_currentProgram = m_programObjects[program];
+            }
+
             Uint ProgramState::CreateShader(ShaderStage stage) {
                 Uint shaderId = 0;
                 m_shaderIndexGenerator.Generate(1, &shaderId);
diff --git a/MobileGL/MG_State/GLState/ProgramState/ProgramState.h b/MobileGL/MG_State/GLState/ProgramState/ProgramState.h
index 85a653a0..ff981cb1 100644
--- a/MobileGL/MG_State/GLState/ProgramState/ProgramState.h
+++ b/MobileGL/MG_State/GLState/ProgramState/ProgramState.h
@@ -15,6 +15,8 @@ namespace MobileGL {
                 void MarkProgramObjectForDeletion(Uint program);
                 Bool ValidateProgramObject(Uint program) const;
 
+                void UseProgram(Uint program);
+
                 Uint CreateShader(ShaderStage stage);
                 SharedPtr<ShaderObject> GetShaderObject(Uint shader);
                 void MarkShaderObjectForDeletion(Uint shader);
@@ -38,6 +40,8 @@ namespace MobileGL {
 
                 IndexGenerator<Uint> m_shaderIndexGenerator;
                 Vector<SharedPtr<ShaderObject>> m_shaderObjects;
+
+                SharedPtr<ProgramObject> m_currentProgram;
             };
         } // namespace GLState
     } // namespace MG_State
diff --git a/MobileGL/MG_State/GLState/ProgramState/ShaderObject.cpp b/MobileGL/MG_State/GLState/ProgramState/ShaderObject.cpp
index fbbd93de..3345f025 100644
--- a/MobileGL/MG_State/GLState/ProgramState/ShaderObject.cpp
+++ b/MobileGL/MG_State/GLState/ProgramState/ShaderObject.cpp
@@ -8,6 +8,10 @@ namespace MobileGL {
                 m_source = source;
             }
 
+            void ShaderObject::SetShaderSource(std::string &&source) {
+                m_source = Move(source);
+            }
+
             void ShaderObject::Compile() {
                 using namespace MG_Util::ShaderTranspiler;
                 ShaderAttrib attrib{
diff --git a/MobileGL/MG_State/GLState/ProgramState/ShaderObject.h b/MobileGL/MG_State/GLState/ProgramState/ShaderObject.h
index c743a629..3d14af78 100644
--- a/MobileGL/MG_State/GLState/ProgramState/ShaderObject.h
+++ b/MobileGL/MG_State/GLState/ProgramState/ShaderObject.h
@@ -58,6 +58,7 @@ namespace MobileGL {
             public:
                 ShaderObject(const ShaderStage stage) : m_stage(stage) {}
                 void SetShaderSource(const std::string& source);
+                void SetShaderSource(std::string&& source);
                 void Compile();
                 void MarkAsDeleted();