Add basic compute shader and ssbo support in rlgl.

src/external/khrplatform.h

@@ -0,0 +1,290 @@
+#ifndef __khrplatform_h_
+#define __khrplatform_h_
+
+/*
+** Copyright (c) 2008-2018 The Khronos Group Inc.
+**
+** Permission is hereby granted, free of charge, to any person obtaining a
+** copy of this software and/or associated documentation files (the
+** "Materials"), to deal in the Materials without restriction, including
+** without limitation the rights to use, copy, modify, merge, publish,
+** distribute, sublicense, and/or sell copies of the Materials, and to
+** permit persons to whom the Materials are furnished to do so, subject to
+** the following conditions:
+**
+** The above copyright notice and this permission notice shall be included
+** in all copies or substantial portions of the Materials.
+**
+** THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+** MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
+*/
+
+/* Khronos platform-specific types and definitions.
+ *
+ * The master copy of khrplatform.h is maintained in the Khronos EGL
+ * Registry repository at https://github.com/KhronosGroup/EGL-Registry
+ * The last semantic modification to khrplatform.h was at commit ID:
+ *      67a3e0864c2d75ea5287b9f3d2eb74a745936692
+ *
+ * Adopters may modify this file to suit their platform. Adopters are
+ * encouraged to submit platform specific modifications to the Khronos
+ * group so that they can be included in future versions of this file.
+ * Please submit changes by filing pull requests or issues on
+ * the EGL Registry repository linked above.
+ *
+ *
+ * See the Implementer's Guidelines for information about where this file
+ * should be located on your system and for more details of its use:
+ *    http://www.khronos.org/registry/implementers_guide.pdf
+ *
+ * This file should be included as
+ *        #include <KHR/khrplatform.h>
+ * by Khronos client API header files that use its types and defines.
+ *
+ * The types in khrplatform.h should only be used to define API-specific types.
+ *
+ * Types defined in khrplatform.h:
+ *    khronos_int8_t              signed   8  bit
+ *    khronos_uint8_t             unsigned 8  bit
+ *    khronos_int16_t             signed   16 bit
+ *    khronos_uint16_t            unsigned 16 bit
+ *    khronos_int32_t             signed   32 bit
+ *    khronos_uint32_t            unsigned 32 bit
+ *    khronos_int64_t             signed   64 bit
+ *    khronos_uint64_t            unsigned 64 bit
+ *    khronos_intptr_t            signed   same number of bits as a pointer
+ *    khronos_uintptr_t           unsigned same number of bits as a pointer
+ *    khronos_ssize_t             signed   size
+ *    khronos_usize_t             unsigned size
+ *    khronos_float_t             signed   32 bit floating point
+ *    khronos_time_ns_t           unsigned 64 bit time in nanoseconds
+ *    khronos_utime_nanoseconds_t unsigned time interval or absolute time in
+ *                                         nanoseconds
+ *    khronos_stime_nanoseconds_t signed time interval in nanoseconds
+ *    khronos_boolean_enum_t      enumerated boolean type. This should
+ *      only be used as a base type when a client API's boolean type is
+ *      an enum. Client APIs which use an integer or other type for
+ *      booleans cannot use this as the base type for their boolean.
+ *
+ * Tokens defined in khrplatform.h:
+ *
+ *    KHRONOS_FALSE, KHRONOS_TRUE Enumerated boolean false/true values.
+ *
+ *    KHRONOS_SUPPORT_INT64 is 1 if 64 bit integers are supported; otherwise 0.
+ *    KHRONOS_SUPPORT_FLOAT is 1 if floats are supported; otherwise 0.
+ *
+ * Calling convention macros defined in this file:
+ *    KHRONOS_APICALL
+ *    KHRONOS_APIENTRY
+ *    KHRONOS_APIATTRIBUTES
+ *
+ * These may be used in function prototypes as:
+ *
+ *      KHRONOS_APICALL void KHRONOS_APIENTRY funcname(
+ *                                  int arg1,
+ *                                  int arg2) KHRONOS_APIATTRIBUTES;
+ */
+
+#if defined(__SCITECH_SNAP__) && !defined(KHRONOS_STATIC)
+#   define KHRONOS_STATIC 1
+#endif
+
+/*-------------------------------------------------------------------------
+ * Definition of KHRONOS_APICALL
+ *-------------------------------------------------------------------------
+ * This precedes the return type of the function in the function prototype.
+ */
+#if defined(KHRONOS_STATIC)
+    /* If the preprocessor constant KHRONOS_STATIC is defined, make the
+     * header compatible with static linking. */
+#   define KHRONOS_APICALL
+#elif defined(_WIN32)
+#   define KHRONOS_APICALL __declspec(dllimport)
+#elif defined (__SYMBIAN32__)
+#   define KHRONOS_APICALL IMPORT_C
+#elif defined(__ANDROID__)
+#   define KHRONOS_APICALL __attribute__((visibility("default")))
+#else
+#   define KHRONOS_APICALL
+#endif
+
+/*-------------------------------------------------------------------------
+ * Definition of KHRONOS_APIENTRY
+ *-------------------------------------------------------------------------
+ * This follows the return type of the function  and precedes the function
+ * name in the function prototype.
+ */
+#if defined(_WIN32) && !defined(_WIN32_WCE) && !defined(__SCITECH_SNAP__)
+    /* Win32 but not WinCE */
+#   define KHRONOS_APIENTRY __stdcall
+#else
+#   define KHRONOS_APIENTRY
+#endif
+
+/*-------------------------------------------------------------------------
+ * Definition of KHRONOS_APIATTRIBUTES
+ *-------------------------------------------------------------------------
+ * This follows the closing parenthesis of the function prototype arguments.
+ */
+#if defined (__ARMCC_2__)
+#define KHRONOS_APIATTRIBUTES __softfp
+#else
+#define KHRONOS_APIATTRIBUTES
+#endif
+
+/*-------------------------------------------------------------------------
+ * basic type definitions
+ *-----------------------------------------------------------------------*/
+#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) || defined(__GNUC__) || defined(__SCO__) || defined(__USLC__)
+
+
+/*
+ * Using <stdint.h>
+ */
+#include <stdint.h>
+typedef int32_t                 khronos_int32_t;
+typedef uint32_t                khronos_uint32_t;
+typedef int64_t                 khronos_int64_t;
+typedef uint64_t                khronos_uint64_t;
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#elif defined(__VMS ) || defined(__sgi)
+
+/*
+ * Using <inttypes.h>
+ */
+#include <inttypes.h>
+typedef int32_t                 khronos_int32_t;
+typedef uint32_t                khronos_uint32_t;
+typedef int64_t                 khronos_int64_t;
+typedef uint64_t                khronos_uint64_t;
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#elif defined(_WIN32) && !defined(__SCITECH_SNAP__)
+
+/*
+ * Win32
+ */
+typedef __int32                 khronos_int32_t;
+typedef unsigned __int32        khronos_uint32_t;
+typedef __int64                 khronos_int64_t;
+typedef unsigned __int64        khronos_uint64_t;
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#elif defined(__sun__) || defined(__digital__)
+
+/*
+ * Sun or Digital
+ */
+typedef int                     khronos_int32_t;
+typedef unsigned int            khronos_uint32_t;
+#if defined(__arch64__) || defined(_LP64)
+typedef long int                khronos_int64_t;
+typedef unsigned long int       khronos_uint64_t;
+#else
+typedef long long int           khronos_int64_t;
+typedef unsigned long long int  khronos_uint64_t;
+#endif /* __arch64__ */
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#elif 0
+
+/*
+ * Hypothetical platform with no float or int64 support
+ */
+typedef int                     khronos_int32_t;
+typedef unsigned int            khronos_uint32_t;
+#define KHRONOS_SUPPORT_INT64   0
+#define KHRONOS_SUPPORT_FLOAT   0
+
+#else
+
+/*
+ * Generic fallback
+ */
+#include <stdint.h>
+typedef int32_t                 khronos_int32_t;
+typedef uint32_t                khronos_uint32_t;
+typedef int64_t                 khronos_int64_t;
+typedef uint64_t                khronos_uint64_t;
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#endif
+
+
+/*
+ * Types that are (so far) the same on all platforms
+ */
+typedef signed   char          khronos_int8_t;
+typedef unsigned char          khronos_uint8_t;
+typedef signed   short int     khronos_int16_t;
+typedef unsigned short int     khronos_uint16_t;
+
+/*
+ * Types that differ between LLP64 and LP64 architectures - in LLP64,
+ * pointers are 64 bits, but 'long' is still 32 bits. Win64 appears
+ * to be the only LLP64 architecture in current use.
+ */
+#ifdef _WIN64
+typedef signed   long long int khronos_intptr_t;
+typedef unsigned long long int khronos_uintptr_t;
+typedef signed   long long int khronos_ssize_t;
+typedef unsigned long long int khronos_usize_t;
+#else
+typedef signed   long  int     khronos_intptr_t;
+typedef unsigned long  int     khronos_uintptr_t;
+typedef signed   long  int     khronos_ssize_t;
+typedef unsigned long  int     khronos_usize_t;
+#endif
+
+#if KHRONOS_SUPPORT_FLOAT
+/*
+ * Float type
+ */
+typedef          float         khronos_float_t;
+#endif
+
+#if KHRONOS_SUPPORT_INT64
+/* Time types
+ *
+ * These types can be used to represent a time interval in nanoseconds or
+ * an absolute Unadjusted System Time.  Unadjusted System Time is the number
+ * of nanoseconds since some arbitrary system event (e.g. since the last
+ * time the system booted).  The Unadjusted System Time is an unsigned
+ * 64 bit value that wraps back to 0 every 584 years.  Time intervals
+ * may be either signed or unsigned.
+ */
+typedef khronos_uint64_t       khronos_utime_nanoseconds_t;
+typedef khronos_int64_t        khronos_stime_nanoseconds_t;
+#endif
+
+/*
+ * Dummy value used to pad enum types to 32 bits.
+ */
+#ifndef KHRONOS_MAX_ENUM
+#define KHRONOS_MAX_ENUM 0x7FFFFFFF
+#endif
+
+/*
+ * Enumerated boolean type
+ *
+ * Values other than zero should be considered to be true.  Therefore
+ * comparisons should not be made against KHRONOS_TRUE.
+ */
+typedef enum {
+    KHRONOS_FALSE = 0,
+    KHRONOS_TRUE  = 1,
+    KHRONOS_BOOLEAN_ENUM_FORCE_SIZE = KHRONOS_MAX_ENUM
+} khronos_boolean_enum_t;
+
+#endif /* __khrplatform_h_ */

src/rlgl.h

@@ -243,6 +243,22 @@
 #define RL_UNSIGNED_BYTE                        0x1401      // GL_UNSIGNED_BYTE
 #define RL_FLOAT                                0x1406      // GL_FLOAT
 
+// Buffer usage hint
+#define RL_STREAM_DRAW                          0x88E0      // GL_STREAM_DRAW
+#define RL_STREAM_READ                          0x88E1      // GL_STREAM_READ
+#define RL_STREAM_COPY                          0x88E2      // GL_STREAM_COPY
+#define RL_STATIC_DRAW                          0x88E4      // GL_STATIC_DRAW
+#define RL_STATIC_READ                          0x88E5      // GL_STATIC_READ
+#define RL_STATIC_COPY                          0x88E6      // GL_STATIC_COPY
+#define RL_DYNAMIC_DRAW                         0x88E8      // GL_DYNAMIC_DRAW
+#define RL_DYNAMIC_READ                         0x88E9      // GL_DYNAMIC_READ
+#define RL_DYNAMIC_COPY                         0x88EA      // GL_DYNAMIC_COPY
+
+// GL Shader type
+#define RL_FRAGMENT_SHADER                      0x8B30      // GL_FRAGMENT_SHADER
+#define RL_VERTEX_SHADER                        0x8B31      // GL_VERTEX_SHADER
+#define RL_COMPUTE_SHADER                       0x91B9      // GL_COMPUTE_SHADER
+
 //----------------------------------------------------------------------------------
 // Types and Structures Definition
 //----------------------------------------------------------------------------------
@@ -619,7 +635,7 @@ RLAPI void rlUnloadFramebuffer(unsigned int id);                          // Del
 
 // Shaders management
 RLAPI unsigned int rlLoadShaderCode(const char *vsCode, const char *fsCode);    // Load shader from code strings
-RLAPI unsigned int rlCompileShader(const char *shaderCode, int type);           // Compile custom shader and return shader id (type: GL_VERTEX_SHADER, GL_FRAGMENT_SHADER)
+RLAPI unsigned int rlCompileShader(const char *shaderCode, int type);           // Compile custom shader and return shader id (type: RL_VERTEX_SHADER, RL_FRAGMENT_SHADER, RL_COMPUTE_SHADER)
 RLAPI unsigned int rlLoadShaderProgram(unsigned int vShaderId, unsigned int fShaderId); // Load custom shader program
 RLAPI void rlUnloadShaderProgram(unsigned int id);                              // Unload shader program
 RLAPI int rlGetLocationUniform(unsigned int shaderId, const char *uniformName); // Get shader location uniform
@@ -629,6 +645,21 @@ RLAPI void rlSetUniformMatrix(int locIndex, Matrix mat);                      //
 RLAPI void rlSetUniformSampler(int locIndex, unsigned int textureId);           // Set shader value sampler
 RLAPI void rlSetShader(unsigned int id, int *locs);                             // Set shader currently active (id and locations)
 
+// Compute shader management
+RLAPI unsigned int rlLoadComputeShaderProgram(int shaderId);
+RLAPI void rlComputeShaderDispatch(unsigned int groupX, unsigned int groupY, unsigned int groupZ);
+
+// Shader buffer storage object management (ssbo)
+RLAPI unsigned int rlLoadShaderBuffer(unsigned long long size, const void *data, int usageHint);
+RLAPI void rlUnloadShaderBuffer(unsigned int ssboId);
+RLAPI void rlUpdateShaderBufferElements(unsigned int id, const void *data, unsigned long long dataSize, unsigned long long offset);
+RLAPI unsigned long long rlGetShaderBufferSize(unsigned int id);
+RLAPI void rlReadShaderBufferElements(unsigned int id, void *dest, unsigned long long count, unsigned long long offset);
+RLAPI void rlBindShaderBuffer(unsigned int id, unsigned int index);
+
+// Buffer management
+RLAPI void rlCopyBuffersElements(unsigned int destId, unsigned int srcId, unsigned long long destOffset, unsigned long long srcOffset, unsigned long long count);
+
 // Matrix state management
 RLAPI Matrix rlGetMatrixModelview(void);                                  // Get internal modelview matrix
 RLAPI Matrix rlGetMatrixProjection(void);                                 // Get internal projection matrix
@@ -688,8 +719,8 @@ RLAPI void rlLoadDrawQuad(void);     // Load and draw a quad
         #define GLAD_REALLOC RL_REALLOC
         #define GLAD_FREE RL_FREE
 
-        #define GLAD_IMPLEMENTATION
+        #include "external/glad.c"      // GLAD extensions loading library, includes OpenGL headers
-        #include "external/glad.h"      // GLAD extensions loading library, includes OpenGL headers
+        #include "external/glad.h"
     #endif
 #endif
 
@@ -888,6 +919,8 @@ typedef struct rlglData {
         bool texCompASTC;                   // ASTC texture compression support (GL_KHR_texture_compression_astc_hdr, GL_KHR_texture_compression_astc_ldr)
         bool texMirrorClamp;                // Clamp mirror wrap mode supported (GL_EXT_texture_mirror_clamp)
         bool texAnisoFilter;                // Anisotropic texture filtering support (GL_EXT_texture_filter_anisotropic)
+        bool computeShader;                 // Compute shaders support (GL_ARB_compute_shader)    
+        bool ssbo;                          // Shader storage buffer object support (GL_ARB_shader_storage_buffer_object)
 
         float maxAnisotropyLevel;           // Maximum anisotropy level supported (minimum is 2.0f)
         int maxDepthBits;                   // Maximum bits for depth component
@@ -1896,6 +1929,8 @@ void rlLoadExtensions(void *loader)
     RLGL.ExtSupported.maxDepthBits = 32;
     RLGL.ExtSupported.texAnisoFilter = true;
     RLGL.ExtSupported.texMirrorClamp = true;
+    if (GLAD_GL_ARB_compute_shader) RLGL.ExtSupported.computeShader = true;
+    if (GLAD_GL_ARB_shader_storage_buffer_object) RLGL.ExtSupported.ssbo = true;    
     #if !defined(__APPLE__)
     // NOTE: With GLAD, we can check if an extension is supported using the GLAD_GL_xxx booleans
     if (GLAD_GL_EXT_texture_compression_s3tc) RLGL.ExtSupported.texCompDXT = true;  // Texture compression: DXT
@@ -2077,6 +2112,8 @@ void rlLoadExtensions(void *loader)
     if (RLGL.ExtSupported.texCompETC2) TRACELOG(RL_LOG_INFO, "GL: ETC2/EAC compressed textures supported");
     if (RLGL.ExtSupported.texCompPVRT) TRACELOG(RL_LOG_INFO, "GL: PVRT compressed textures supported");
     if (RLGL.ExtSupported.texCompASTC) TRACELOG(RL_LOG_INFO, "GL: ASTC compressed textures supported");
+    if (RLGL.ExtSupported.computeShader) TRACELOG(RL_LOG_INFO, "GL: Compute shaders supported");
+    if (RLGL.ExtSupported.ssbo) TRACELOG(RL_LOG_INFO, "GL: Shader storage buffer objects supported");
 #endif  // SUPPORT_GL_DETAILS_INFO
 
 #endif  // GRAPHICS_API_OPENGL_33 || GRAPHICS_API_OPENGL_ES2
@@ -3507,7 +3544,7 @@ unsigned int rlCompileShader(const char *shaderCode, int type)
             case GL_VERTEX_SHADER: TRACELOG(RL_LOG_WARNING, "SHADER: [ID %i] Failed to compile vertex shader code", shader); break;
             case GL_FRAGMENT_SHADER: TRACELOG(RL_LOG_WARNING, "SHADER: [ID %i] Failed to compile fragment shader code", shader); break;
             //case GL_GEOMETRY_SHADER:
-            //case GL_COMPUTE_SHADER:
+            case GL_COMPUTE_SHADER: TRACELOG(RL_LOG_WARNING, "SHADER: [ID %i] Failed to compile compute shader code", shader); break;
             default: break;
         }
 
@@ -3530,7 +3567,7 @@ unsigned int rlCompileShader(const char *shaderCode, int type)
             case GL_VERTEX_SHADER: TRACELOG(RL_LOG_INFO, "SHADER: [ID %i] Vertex shader compiled successfully", shader); break;
             case GL_FRAGMENT_SHADER: TRACELOG(RL_LOG_INFO, "SHADER: [ID %i] Fragment shader compiled successfully", shader); break;
             //case GL_GEOMETRY_SHADER:
-            //case GL_COMPUTE_SHADER:
+            case GL_COMPUTE_SHADER: TRACELOG(RL_LOG_INFO, "SHADER: [ID %i] Compute shader compiled successfully", shader); break;
             default: break;
         }
     }
@@ -3719,6 +3756,123 @@ void rlSetShader(unsigned int id, int *locs)
 #endif
 }
 
+unsigned int rlLoadComputeShaderProgram(int shaderId)
+{
+    unsigned int program = 0;
+
+#if defined(GRAPHICS_API_OPENGL_33)
+    GLint success = 0;
+    program = glCreateProgram();
+    glAttachShader(program, shaderId);
+    glLinkProgram(program);
+
+    // NOTE: All uniform variables are intitialised to 0 when a program links
+
+    glGetProgramiv(program, GL_LINK_STATUS, &success);
+
+    if (success == GL_FALSE)
+    {
+        TRACELOG(RL_LOG_WARNING, "SHADER: [ID %i] Failed to link compute shader program", program);
+
+        int maxLength = 0;
+        glGetProgramiv(program, GL_INFO_LOG_LENGTH, &maxLength);
+
+        if (maxLength > 0)
+        {
+            int length = 0;
+            char *log = RL_CALLOC(maxLength, sizeof(char));
+            glGetProgramInfoLog(program, maxLength, &length, log);
+            TRACELOG(RL_LOG_WARNING, "SHADER: [ID %i] Link error: %s", program, log);
+            RL_FREE(log);
+        }
+
+        glDeleteProgram(program);
+
+        program = 0;
+    }
+    else
+    {
+        // Get the size of compiled shader program (not available on OpenGL ES 2.0)
+        // NOTE: If GL_LINK_STATUS is GL_FALSE, program binary length is zero.
+        //GLint binarySize = 0;
+        //glGetProgramiv(id, GL_PROGRAM_BINARY_LENGTH, &binarySize);
+
+        TRACELOG(RL_LOG_INFO, "SHADER: [ID %i] Compute shader program loaded successfully", program);
+    }
+#endif
+    return program;
+}
+
+void rlComputeShaderDispatch(unsigned int groupX, unsigned int groupY, unsigned int groupZ)
+{
+#if defined(GRAPHICS_API_OPENGL_33)
+    glDispatchCompute(groupX, groupY, groupZ);
+#endif
+}
+
+unsigned int rlLoadShaderBuffer(unsigned long long size, const void *data, int usageHint)
+{
+    unsigned int ssbo = 0;
+#if defined(GRAPHICS_API_OPENGL_33)
+    glGenBuffers(1, &ssbo);
+    glBindBuffer(GL_SHADER_STORAGE_BUFFER, ssbo);
+    glBufferData(GL_SHADER_STORAGE_BUFFER, size, data, usageHint? usageHint : RL_STREAM_COPY);
+#endif
+    return ssbo;
+}
+
+void rlUnloadShaderBuffer(unsigned int ssboId)
+{
+#if defined(GRAPHICS_API_OPENGL_33)
+    glDeleteBuffers(1, &ssboId);
+#endif
+}
+
+void rlUpdateShaderBufferElements(unsigned int id, const void *data, unsigned long long dataSize, unsigned long long offset)
+{
+#if defined(GRAPHICS_API_OPENGL_33)
+    glBindBuffer(GL_SHADER_STORAGE_BUFFER, id);
+    glBufferSubData(GL_SHADER_STORAGE_BUFFER, offset, dataSize, data);
+#endif
+}
+
+unsigned long long rlGetShaderBufferSize(unsigned int id)
+{
+    khronos_int64_t size = 0;
+
+#if defined(GRAPHICS_API_OPENGL_33)
+    glBindBuffer(GL_SHADER_STORAGE_BUFFER, id);
+    glGetInteger64v(GL_SHADER_STORAGE_BUFFER_SIZE, &size);
+#endif
+
+    return (size > 0) ? size : 0;
+}
+
+void rlReadShaderBufferElements(unsigned int id, void *dest, unsigned long long count, unsigned long long offset)
+{
+#if defined(GRAPHICS_API_OPENGL_33)
+    glBindBuffer(GL_SHADER_STORAGE_BUFFER, id);
+    glGetBufferSubData(GL_SHADER_STORAGE_BUFFER, offset, count, dest);
+#endif
+}
+
+void rlBindShaderBuffer(unsigned int id, unsigned int index)
+{
+#if defined(GRAPHICS_API_OPENGL_33)
+    glBindBufferBase(GL_SHADER_STORAGE_BUFFER, index, id);
+#endif
+}
+
+void rlCopyBuffersElements(unsigned int destId, unsigned int srcId, unsigned long long destOffset, unsigned long long srcOffset, unsigned long long count)
+{
+#if defined(GRAPHICS_API_OPENGL_33)
+    glBindBuffer(GL_COPY_READ_BUFFER, srcId);
+    glBindBuffer(GL_COPY_WRITE_BUFFER, destId);
+    glCopyBufferSubData(GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER, srcOffset, destOffset, count);
+#endif
+}
+
+
 // Matrix state management
 //-----------------------------------------------------------------------------------------
 // Get internal modelview matrix