+#define MAT4_MUL(dest_vec, src_mat, src_vec) \
+ "DP4 " dest_vec ".x, " src_mat "[0], " src_vec ";\n" \
+ "DP4 " dest_vec ".y, " src_mat "[1], " src_vec ";\n" \
+ "DP4 " dest_vec ".z, " src_mat "[2], " src_vec ";\n" \
+ "DP4 " dest_vec ".w, " src_mat "[3], " src_vec ";\n"
+
+#define MAT3_MUL(dest_vec, src_mat, src_vec) \
+ "DP3 " dest_vec ".x, " src_mat "[0], " src_vec ";\n" \
+ "DP3 " dest_vec ".y, " src_mat "[1], " src_vec ";\n" \
+ "DP3 " dest_vec ".z, " src_mat "[2], " src_vec ";\n"
+
+#define NORMALIZE(dest, src) \
+ "DP3 " dest ".w, " src ", " src ";\n" \
+ "RSQ " dest ".w, " dest ".w;\n" \
+ "MUL " dest ", " src ", " dest ".w;\n"
+
+/**
+ * Vertex program for shadow mapping.
+ */
+static const char vert_code[] =
+ "!!ARBvp1.0\n"
+ "ATTRIB iPos = vertex.position;\n"
+ "ATTRIB iNorm = vertex.normal;\n"
+
+ "PARAM mvinv[4] = { state.matrix.modelview.invtrans };\n"
+ "PARAM mvp[4] = { state.matrix.mvp };\n"
+ "PARAM mv[4] = { state.matrix.modelview };\n"
+ "PARAM texmat[4] = { state.matrix.texture[0] };\n"
+ "PARAM lightPos = state.light[0].position;\n"
+ "PARAM ambientCol = state.lightprod[0].ambient;\n"
+ "PARAM diffuseCol = state.lightprod[0].diffuse;\n"
+
+ "TEMP n, lightVec;\n"
+ "ALIAS V = lightVec;\n"
+ "ALIAS NdotL = n;\n"
+
+ "OUTPUT oPos = result.position;\n"
+ "OUTPUT oColor = result.color;\n"
+ "OUTPUT oTex = result.texcoord[0];\n"
+
+ /* Transform the vertex to clip coordinates. */
+ MAT4_MUL("oPos", "mvp", "iPos")
+
+ /* Transform the vertex to eye coordinates. */
+ MAT4_MUL("V", "mv", "iPos")
+
+ /* Transform the vertex to projected light coordinates. */
+ MAT4_MUL("oTex", "texmat", "iPos")
+
+ /* Transform the normal to eye coordinates. */
+ MAT3_MUL("n", "mvinv", "iNorm")
+
+ /* Calculate the vector from the vertex to the light in eye
+ * coordinates.
+ */
+ "SUB lightVec, lightPos, V;\n"
+ NORMALIZE("lightVec", "lightVec")
+
+ /* Compute diffuse lighting coefficient.
+ */
+ "DP3 NdotL.x, n, lightVec;\n"
+ "MAX NdotL.x, NdotL.x, {0.0};\n"
+ "MIN NdotL.x, NdotL.x, {1.0};\n"
+
+ /* Accumulate color contributions.
+ */
+ "MOV oColor, diffuseCol;\n"
+ "MAD oColor.xyz, NdotL.x, diffuseCol, ambientCol;\n"
+ "END\n"
+ ;
+
+static const char frag_code[] =
+ "!!ARBfp1.0\n"
+
+ "TEMP shadow, temp;\n"
+
+ "TXP shadow, fragment.texcoord[0], texture[0], 2D;\n"
+ "RCP temp.x, fragment.texcoord[0].w;\n"
+ "MUL temp.x, temp.x, fragment.texcoord[0].z;\n"
+ "SGE shadow, shadow.x, temp.x;\n"
+ "MUL result.color.rgb, fragment.color, shadow.x;\n"
+ "MOV result.color.a, fragment.color;\n"
+ "END\n"
+ ;
+
+static const char frag_shadow_code[] =
+ "!!ARBfp1.0\n"
+ "OPTION ARB_fragment_program_shadow;\n"
+
+ "TEMP shadow;\n"
+
+ "TXP shadow, fragment.texcoord[0], texture[0], SHADOW2D;\n"
+ "MUL result.color.rgb, fragment.color, shadow.x;\n"
+ "MOV result.color.a, fragment.color.a;\n"
+ "END\n"
+ ;
+