diff --git a/src/renderer/gl_engine/tvgGlRenderer.cpp b/src/renderer/gl_engine/tvgGlRenderer.cpp
index 21323d49..d0aa744f 100644
--- a/src/renderer/gl_engine/tvgGlRenderer.cpp
+++ b/src/renderer/gl_engine/tvgGlRenderer.cpp
@@ -98,9 +98,36 @@ void GlRenderer::initShaders()
 {
     mPrograms.reserve((int)RT_None);
 
+#define COMMON_TOTAL_LENGTH strlen(STR_GRADIENT_FRAG_COMMON_VARIABLES) + \
+                            strlen(STR_GRADIENT_FRAG_COMMON_FUNCTIONS)
+
+#define LINEAR_TOTAL_LENGTH strlen(STR_LINEAR_GRADIENT_VARIABLES) + \
+                            strlen(STR_LINEAR_GRADIENT_MAIN) + \
+                            COMMON_TOTAL_LENGTH + 1
+
+#define RADIAL_TOTAL_LENGTH strlen(STR_RADIAL_GRADIENT_VARIABLES) + \
+                            strlen(STR_RADIAL_GRADIENT_MAIN) + \
+                            COMMON_TOTAL_LENGTH + 1
+
+    char linearGradientFragShader[LINEAR_TOTAL_LENGTH];
+    snprintf(linearGradientFragShader, LINEAR_TOTAL_LENGTH, "%s%s%s%s",
+        STR_GRADIENT_FRAG_COMMON_VARIABLES,
+        STR_LINEAR_GRADIENT_VARIABLES,
+        STR_GRADIENT_FRAG_COMMON_FUNCTIONS,
+        STR_LINEAR_GRADIENT_MAIN
+    );
+
+    char radialGradientFragShader[RADIAL_TOTAL_LENGTH];
+    snprintf(radialGradientFragShader, RADIAL_TOTAL_LENGTH, "%s%s%s%s",
+        STR_GRADIENT_FRAG_COMMON_VARIABLES,
+        STR_RADIAL_GRADIENT_VARIABLES,
+        STR_GRADIENT_FRAG_COMMON_FUNCTIONS,
+        STR_RADIAL_GRADIENT_MAIN
+    );
+
     mPrograms.push(new GlProgram(COLOR_VERT_SHADER, COLOR_FRAG_SHADER));
-    mPrograms.push(new GlProgram(GRADIENT_VERT_SHADER, LINEAR_GRADIENT_FRAG_SHADER));
-    mPrograms.push(new GlProgram(GRADIENT_VERT_SHADER, RADIAL_GRADIENT_FRAG_SHADER));
+    mPrograms.push(new GlProgram(GRADIENT_VERT_SHADER, linearGradientFragShader));
+    mPrograms.push(new GlProgram(GRADIENT_VERT_SHADER, radialGradientFragShader));
     mPrograms.push(new GlProgram(IMAGE_VERT_SHADER, IMAGE_FRAG_SHADER));
 
     // compose Renderer
diff --git a/src/renderer/gl_engine/tvgGlShaderSrc.cpp b/src/renderer/gl_engine/tvgGlShaderSrc.cpp
index 8243a058..d35d5a3f 100644
--- a/src/renderer/gl_engine/tvgGlShaderSrc.cpp
+++ b/src/renderer/gl_engine/tvgGlShaderSrc.cpp
@@ -20,7 +20,6 @@
  * SOFTWARE.
  */
 
-#include <string>
 #include "tvgGlShaderSrc.h"
 
 #define TVG_COMPOSE_SHADER(shader) #shader
@@ -75,12 +74,12 @@ const char* GRADIENT_VERT_SHADER = TVG_COMPOSE_SHADER(
 );
 
 
-std::string STR_GRADIENT_FRAG_COMMON_VARIABLES = TVG_COMPOSE_SHADER(
+const char* STR_GRADIENT_FRAG_COMMON_VARIABLES = TVG_COMPOSE_SHADER(
     const int MAX_STOP_COUNT = 16;                                                                          \n
     in vec2 vPos;                                                                                           \n
 );
 
-std::string STR_GRADIENT_FRAG_COMMON_FUNCTIONS = TVG_COMPOSE_SHADER(
+const char* STR_GRADIENT_FRAG_COMMON_FUNCTIONS = TVG_COMPOSE_SHADER(
     float gradientStep(float edge0, float edge1, float x)                                                   \n
     {                                                                                                       \n
         // linear                                                                                           \n
@@ -170,7 +169,7 @@ std::string STR_GRADIENT_FRAG_COMMON_FUNCTIONS = TVG_COMPOSE_SHADER(
     }                                                                                                       \n
 );
 
-std::string STR_LINEAR_GRADIENT_VARIABLES = TVG_COMPOSE_SHADER(
+const char* STR_LINEAR_GRADIENT_VARIABLES = TVG_COMPOSE_SHADER(
     layout(std140) uniform GradientInfo {                                                                   \n
         vec4  nStops;                                                                                       \n
         vec2  gradStartPos;                                                                                 \n
@@ -180,7 +179,7 @@ std::string STR_LINEAR_GRADIENT_VARIABLES = TVG_COMPOSE_SHADER(
     } uGradientInfo;                                                                                        \n
 );
 
-std::string STR_LINEAR_GRADIENT_MAIN = TVG_COMPOSE_SHADER(
+const char* STR_LINEAR_GRADIENT_MAIN = TVG_COMPOSE_SHADER(
     out vec4 FragColor;                                                                                     \n
     void main()                                                                                             \n
     {                                                                                                       \n
@@ -195,7 +194,7 @@ std::string STR_LINEAR_GRADIENT_MAIN = TVG_COMPOSE_SHADER(
     }                                                                                                       \n
 );
 
-std::string STR_RADIAL_GRADIENT_VARIABLES = TVG_COMPOSE_SHADER(
+const char* STR_RADIAL_GRADIENT_VARIABLES = TVG_COMPOSE_SHADER(
     layout(std140) uniform GradientInfo {                                                                   \n
         vec4  nStops;                                                                                       \n
         vec4  centerPos;                                                                                    \n
@@ -205,7 +204,7 @@ std::string STR_RADIAL_GRADIENT_VARIABLES = TVG_COMPOSE_SHADER(
     } uGradientInfo ;                                                                                       \n
 );
 
-std::string STR_RADIAL_GRADIENT_MAIN = TVG_COMPOSE_SHADER(
+const char* STR_RADIAL_GRADIENT_MAIN = TVG_COMPOSE_SHADER(
     out vec4 FragColor;                                                                                     \n
                                                                                                             \n
     mat3 radial_matrix(vec2 p0, vec2 p1)                                                                    \n
@@ -314,23 +313,6 @@ std::string STR_RADIAL_GRADIENT_MAIN = TVG_COMPOSE_SHADER(
     }
 );
 
-std::string STR_LINEAR_GRADIENT_FRAG_SHADER =
-STR_GRADIENT_FRAG_COMMON_VARIABLES +
-STR_LINEAR_GRADIENT_VARIABLES +
-STR_GRADIENT_FRAG_COMMON_FUNCTIONS +
-STR_LINEAR_GRADIENT_MAIN;
-
-const char* LINEAR_GRADIENT_FRAG_SHADER = STR_LINEAR_GRADIENT_FRAG_SHADER.c_str();
-
-std::string STR_RADIAL_GRADIENT_FRAG_SHADER =
-STR_GRADIENT_FRAG_COMMON_VARIABLES +
-STR_RADIAL_GRADIENT_VARIABLES +
-STR_GRADIENT_FRAG_COMMON_FUNCTIONS +
-STR_RADIAL_GRADIENT_MAIN;
-
-const char* RADIAL_GRADIENT_FRAG_SHADER = STR_RADIAL_GRADIENT_FRAG_SHADER.c_str();
-
-
 const char* IMAGE_VERT_SHADER = TVG_COMPOSE_SHADER(
     uniform float uDepth;                                                                   \n
     layout (location = 0) in vec2 aLocation;                                                \n
diff --git a/src/renderer/gl_engine/tvgGlShaderSrc.h b/src/renderer/gl_engine/tvgGlShaderSrc.h
index 94716751..bc793168 100644
--- a/src/renderer/gl_engine/tvgGlShaderSrc.h
+++ b/src/renderer/gl_engine/tvgGlShaderSrc.h
@@ -26,8 +26,12 @@
 extern const char* COLOR_VERT_SHADER;
 extern const char* COLOR_FRAG_SHADER;
 extern const char* GRADIENT_VERT_SHADER;
-extern const char* LINEAR_GRADIENT_FRAG_SHADER;
-extern const char* RADIAL_GRADIENT_FRAG_SHADER;
+extern const char* STR_GRADIENT_FRAG_COMMON_VARIABLES;
+extern const char* STR_GRADIENT_FRAG_COMMON_FUNCTIONS;
+extern const char* STR_LINEAR_GRADIENT_VARIABLES;
+extern const char* STR_LINEAR_GRADIENT_MAIN;
+extern const char* STR_RADIAL_GRADIENT_VARIABLES;
+extern const char* STR_RADIAL_GRADIENT_MAIN;
 extern const char* IMAGE_VERT_SHADER;
 extern const char* IMAGE_FRAG_SHADER;
 extern const char* MASK_VERT_SHADER;