Manually transpose matricies in shader

Since GLES2 doesn't do this for us, it seems, on all platforms.

render/gles2/renderer.c

@@ -142,7 +142,7 @@ static bool wlr_gles2_render_surface(struct wlr_renderer_state *state,
 	}
 	gles2_flush_errors();
 	wlr_surface_bind(surface);
-	GL_CALL(glUniformMatrix4fv(0, 1, GL_TRUE, *matrix));
+	GL_CALL(glUniformMatrix4fv(0, 1, GL_FALSE, *matrix));
 	draw_quad();
 	return true;
 }

render/gles2/shaders.c

@@ -9,8 +9,22 @@ const GLchar quad_vertex_src[] =
 "attribute vec2 texcoord;"
 "varying vec4 v_color;"
 "varying vec2 v_texcoord;"
+"mat4 transpose(in mat4 inMatrix) {"
+"    vec4 i0 = inMatrix[0];"
+"    vec4 i1 = inMatrix[1];"
+"    vec4 i2 = inMatrix[2];"
+"    vec4 i3 = inMatrix[3];"
+"    mat4 outMatrix = mat4("
+"                 vec4(i0.x, i1.x, i2.x, i3.x),"
+"                 vec4(i0.y, i1.y, i2.y, i3.y),"
+"                 vec4(i0.z, i1.z, i2.z, i3.z),"
+"                 vec4(i0.w, i1.w, i2.w, i3.w)"
+"                 );"
+""
+"    return outMatrix;"
+"}"
 "void main() {"
-"  gl_Position = proj * vec4(pos, 0.0, 1.0);"
+"  gl_Position = transpose(proj) * vec4(pos, 0.0, 1.0);"
 "  v_color = color;"
 "  v_texcoord = texcoord;"
 "}";
@@ -41,8 +55,22 @@ const GLchar vertex_src[] =
 "attribute vec2 pos;"
 "attribute vec2 texcoord;"
 "varying vec2 v_texcoord;"
+"mat4 transpose(in mat4 inMatrix) {"
+"    vec4 i0 = inMatrix[0];"
+"    vec4 i1 = inMatrix[1];"
+"    vec4 i2 = inMatrix[2];"
+"    vec4 i3 = inMatrix[3];"
+"    mat4 outMatrix = mat4("
+"                 vec4(i0.x, i1.x, i2.x, i3.x),"
+"                 vec4(i0.y, i1.y, i2.y, i3.y),"
+"                 vec4(i0.z, i1.z, i2.z, i3.z),"
+"                 vec4(i0.w, i1.w, i2.w, i3.w)"
+"                 );"
+""
+"    return outMatrix;"
+"}"
 "void main() {"
-"	gl_Position = proj * vec4(pos, 0.0, 1.0);"
+"	gl_Position = transpose(proj) * vec4(pos, 0.0, 1.0);"
 "	v_texcoord = texcoord;"
 "}";