-/*
- * Apply the alpha test to a span of pixels.
- * In: rgba - array of pixels
- * In/Out: span -
- * Return: 0 = all pixels in the span failed the alpha test.
- * 1 = one or more pixels passed the alpha test.
+#define ALPHA_TEST(ALPHA, LOOP_CODE) \
+do { \
+ switch (ctx->Color.AlphaFunc) { \
+ case GL_LESS: \
+ for (i = 0; i < n; i++) { \
+ mask[i] &= (ALPHA < ref); \
+ LOOP_CODE; \
+ } \
+ break; \
+ case GL_LEQUAL: \
+ for (i = 0; i < n; i++) { \
+ mask[i] &= (ALPHA <= ref); \
+ LOOP_CODE; \
+ } \
+ break; \
+ case GL_GEQUAL: \
+ for (i = 0; i < n; i++) { \
+ mask[i] &= (ALPHA >= ref); \
+ LOOP_CODE; \
+ } \
+ break; \
+ case GL_GREATER: \
+ for (i = 0; i < n; i++) { \
+ mask[i] &= (ALPHA > ref); \
+ LOOP_CODE; \
+ } \
+ break; \
+ case GL_NOTEQUAL: \
+ for (i = 0; i < n; i++) { \
+ mask[i] &= (ALPHA != ref); \
+ LOOP_CODE; \
+ } \
+ break; \
+ case GL_EQUAL: \
+ for (i = 0; i < n; i++) { \
+ mask[i] &= (ALPHA == ref); \
+ LOOP_CODE; \
+ } \
+ break; \
+ default: \
+ _mesa_problem(ctx, "Invalid alpha test in _swrast_alpha_test" ); \
+ return 0; \
+ } \
+} while (0)
+
+
+
+/**
+ * Perform the alpha test for an array of pixels.
+ * For pixels that fail the test, mask[i] will be set to 0.
+ * \return 0 if all pixels in the span failed the alpha test,
+ * 1 if one or more pixels passed the alpha test.