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copied!<p>With OpenGL up to version not including 3 you can replace it with the following:</p> <pre><code>void GL2_SetTransform(float x, float y, float dx, float dy, float rot, float hscale, float vscale) { glMatrixMode(GL_MODELVIEW); glLoadIdentity(); // we start off a identity matrix // Instead of testing for 0, you should test for some // threshold, to increase numerical stability if( fabs(vscale) >= 1e-7 ) { glTranslatef(-x, -y, 0.0f); glScalef(hscale, vscale, 1.0f); glRotatef(-rot, 0., 0., 1.); glTranslatef(x+dx, y+dy, 0.0f); } } </code></pre> <p>OpenGL-3 deprecated the matrix manipulation functions, so the code looks almost identical to the DirectX version (I changed a few things to improve stability):</p> <pre><code>typedef float mat4x4[4][4]; // OpenGL uses column major mode, so the first // index selects column, the second row - this is // opposite to the usual C notation. // The following functions must be implemented as well. // But they're easy enough. // function to set the matrix to identity void mat4x4_identity(mat4x4 *M); // those functions transform the matrix in-place, // i.e. no temporaries needed. void mat4x4_rotX(mat4x4 *M, float angle); void mat4x4_rotY(mat4x4 *M, float angle); void mat4x4_rotZ(mat4x4 *M, float angle); void mat4x4_scale(mat4x4 *M, float x, float y, float z); void mat4x4_translate(mat4x4 *M, float x, float y, float z); void GL3_SetTransform(float x, float y, float dx, float dy, float rot, float hscale, float vscale) { mat4x4 view; mat4x4_identity(view); if( fabs(vscale) >= 1e-8 ) { mat4x4_translate(view, -x, -y, 0.0f); mat4x4_scale(view, hscale, vscale, 1.0f); mat4x4_rotZ(view, -rot); mat4x4_translate(view, x+dx, y+dy, 0.0f); } _render_batch(); // get_view_uniform_location returns the handle for the currently loaded // shader's modelview matrix' location. Application specific, so you've to // come up with that yourself. glUniformMatrix4fv(get_view_uniform_locaton(), 1, false, view); } </code></pre> <p>I put up source code for the matrix manipulation functions up here: <a href="http://pastebin.com/R0PHTW0M" rel="nofollow">http://pastebin.com/R0PHTW0M</a> They're not using exactly the same naming scheme, though.</p>

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