Makefile: build all backends with optional HDR output

Makefile

@@ -5,6 +5,7 @@ LDLIBS ?= -lm
 ENABLE_PNG ?= 1
 SPACETIME ?= minkowski
 BUILD_TYPE ?= Release
+ENABLE_HDR ?= 0
 
 ifeq ($(BUILD_TYPE),Release)
 BUILD_CFLAGS := -O2 -DNDEBUG
@@ -27,16 +28,16 @@ endif
 COMMON_SOURCES := $(filter-out src/main.c src/spacetime_minkowski.c src/spacetime_schwarzschild.c,$(wildcard src/*.c))
 PROVIDER_SOURCE := src/spacetime_$(SPACETIME).c
 BUILD_DIR := build/$(BUILD_TYPE)
-TARGET := $(BUILD_DIR)/$(SPACETIME)_sky
+TARGET_BASENAME := $(SPACETIME)_sky
+OBJECT_DIR := $(BUILD_DIR)/obj/$(SPACETIME)
 CORE_MINKOWSKI_SOURCES := $(COMMON_SOURCES) src/spacetime_minkowski.c
 TEST_TARGET := $(BUILD_DIR)/test_geodesic
 FRAME_TEST_TARGET := $(BUILD_DIR)/test_frame
 SCHWARZSCHILD_TEST_TARGET := $(BUILD_DIR)/test_schwarzschild
 OBSERVER_TRACK_TEST_TARGET := $(BUILD_DIR)/test_observer_track
 CATALOG_PREFETCH_TEST_TARGET := $(BUILD_DIR)/test_catalog_prefetch
-PSF_HDR_TEST_TARGET := $(BUILD_DIR)/minkowski_psf_hdr_test
 
-.PHONY: all clean run test minkowski schwarzschild psf-hdr-test
+.PHONY: all backend clean run test minkowski schwarzschild FORCE
 
 ifeq ($(SPACETIME),minkowski)
 BACKEND_CPPFLAGS := -DSPACETIME_MINKOWSKI
@@ -46,10 +47,48 @@ else
 $(error Unknown SPACETIME '$(SPACETIME)'; choose minkowski or schwarzschild)
 endif
 
-all: $(TARGET)
+ifeq ($(ENABLE_HDR),1)
+HDR_CPPFLAGS := -DENABLE_HDR_OUTPUT $(shell pkg-config --cflags cfitsio)
+HDR_LDLIBS := $(shell pkg-config --libs cfitsio)
+HDR_BUILD_TAG := hdr
+else ifeq ($(ENABLE_HDR),0)
+HDR_BUILD_TAG := standard
+else
+$(error Unknown ENABLE_HDR '$(ENABLE_HDR)'; choose 0 or 1)
+endif
 
-$(TARGET): $(COMMON_SOURCES) $(PROVIDER_SOURCE) src/main.c | $(BUILD_DIR)
-	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(BACKEND_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $^ $(LDLIBS) -o $@
+TARGET := $(BUILD_DIR)/$(TARGET_BASENAME)
+RENDER_SOURCES := $(COMMON_SOURCES) $(PROVIDER_SOURCE) src/main.c
+RENDER_OBJECTS := $(patsubst %.c,$(OBJECT_DIR)/$(HDR_BUILD_TAG)/%.o,$(RENDER_SOURCES))
+RENDER_DEPS := $(RENDER_OBJECTS:.o=.d)
+
+# With no explicit backend choice, all means every currently supported
+# production spacetime backend. An explicit SPACETIME selects that backend,
+# so `make SPACETIME=schwarzschild` remains the direct build command.
+ifneq ($(filter command\ line environment environment\ override,$(origin SPACETIME)),)
+all: backend
+else
+all: minkowski schwarzschild
+endif
+
+minkowski:
+	$(MAKE) SPACETIME=minkowski ENABLE_HDR=$(ENABLE_HDR) backend
+
+schwarzschild:
+	$(MAKE) SPACETIME=schwarzschild ENABLE_HDR=$(ENABLE_HDR) backend
+
+# Build exactly the selected backend/configuration, e.g.
+# make SPACETIME=schwarzschild ENABLE_HDR=1 backend
+backend: $(TARGET)
+
+$(TARGET): $(RENDER_OBJECTS) FORCE | $(BUILD_DIR)
+	$(CC) $(BUILD_CFLAGS) $(OPENMP_FLAGS) $(RENDER_OBJECTS) $(LDLIBS) $(HDR_LDLIBS) -o $@
+
+FORCE:
+
+$(OBJECT_DIR)/$(HDR_BUILD_TAG)/%.o: %.c
+	@mkdir -p $(dir $@)
+	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(BACKEND_CPPFLAGS) $(HDR_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc -MMD -MP -c $< -o $@
 
 $(BUILD_DIR):
 	mkdir -p $@
@@ -58,18 +97,6 @@ run: $(TARGET)
 	mkdir -p output/imgs
 	./$(TARGET) --catalog assets/sky_grid_5deg.csv --output output/imgs/$(SPACETIME)_sky.$(IMAGE_EXT)
 
-minkowski:
-	$(MAKE) SPACETIME=minkowski all
-
-schwarzschild:
-	$(MAKE) SPACETIME=schwarzschild all
-
-# Deliberately separate from the production binary: enables --hdr-output FITS.
-$(PSF_HDR_TEST_TARGET): $(COMMON_SOURCES) src/spacetime_minkowski.c src/main.c | $(BUILD_DIR)
-	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) -DENABLE_HDR_DEBUG -DSPACETIME_MINKOWSKI $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $^ $(LDLIBS) $(shell pkg-config --libs cfitsio) -o $@
-
-psf-hdr-test: $(PSF_HDR_TEST_TARGET)
-
 $(TEST_TARGET): tests/test_geodesic.c $(CORE_MINKOWSKI_SOURCES) | $(BUILD_DIR)
 	$(CC) $(CPPFLAGS) $(BUILD_CPPFLAGS) $(CFLAGS) $(BUILD_CFLAGS) $(OPENMP_FLAGS) -Isrc $^ $(LDLIBS) -o $@
 
@@ -94,3 +121,5 @@ test: $(TEST_TARGET) $(FRAME_TEST_TARGET) $(SCHWARZSCHILD_TEST_TARGET) $(OBSERVE
 
 clean:
 	rm -rf build
+
+-include $(RENDER_DEPS)

README.md

@@ -253,11 +253,13 @@ count and each time slab's activation and terminal-ray summary.
 Movie renders always print one summary per time slab; `--verbose` also prints
 the ray counts before each slab is loaded.
 
-For PSF validation only, `make psf-hdr-test` builds
-`build/minkowski_psf_hdr_test`, a separate binary with a `--hdr-output PATH`
-option.  It writes the pre-tone-mapping RGB framebuffer as a three-plane,
-32-bit float FITS image.  Values remain linear HDR at the renderer's arbitrary
-scale; no tone mapping or per-frame normalization is applied.  The ordinary
+To preserve a render for later exposure and tone-mapping work, build the desired
+backend with `ENABLE_HDR=1`, for example `make SPACETIME=schwarzschild
+ENABLE_HDR=1`. This produces `build/Release/schwarzschild_sky`,
+which accepts `--hdr-output PATH`. It writes the pre-tone-mapping RGB
+framebuffer as a three-plane, 32-bit float FITS image. Values remain linear HDR
+at the renderer's arbitrary scale; no tone mapping or per-frame normalization
+is applied. The ordinary
 binaries do not contain this option or writer.
 
 The FITS header describes a synthetic 8640-by-5760, 36-by-24 mm full-frame

src/main.c

@@ -31,7 +31,7 @@ typedef struct {
   const char *catalog_path;
   const char *all_sky_catalog_path;
   const char *output_path;
-#ifdef ENABLE_HDR_DEBUG
+#ifdef ENABLE_HDR_OUTPUT
   const char *hdr_output_path;
 #endif
   const char *observer_track_path;
@@ -189,7 +189,7 @@ static int parse_args(int argc, char **argv, Settings *s,
       s->all_sky_catalog_path = argv[++i];
     else if (!strcmp(argv[i], "--output") && i + 1 < argc)
       s->output_path = argv[++i];
-#ifdef ENABLE_HDR_DEBUG
+#ifdef ENABLE_HDR_OUTPUT
     else if (!strcmp(argv[i], "--hdr-output") && i + 1 < argc)
       s->hdr_output_path = argv[++i];
 #endif
@@ -449,7 +449,7 @@ static int render_observer_frame(const Settings *s, StarCatalog *catalog,
                             &progress});
   if (s->draw_mesh)
     frame_draw_mesh(&mesh, hdr, s->width, s->height, 0.5, 0.5);
-#ifdef ENABLE_HDR_DEBUG
+#ifdef ENABLE_HDR_OUTPUT
   if (s->hdr_output_path != NULL &&
       write_hdr_fits(s->hdr_output_path, hdr, s->width, s->height,
                      s->horizontal_fov_deg)) {
@@ -666,7 +666,7 @@ int main(int argc, char **argv) {
             "[--psf-fwhm-pixels N] [--psf-moffat-beta N] "
             "[--max-magnification M] [--max-cache-psf-flux F] "
             "[--psf-direct] [--verbose] "
-#ifdef ENABLE_HDR_DEBUG
+#ifdef ENABLE_HDR_OUTPUT
             "[--hdr-output PATH] "
 #endif
             "[--coarse-cell-pixels N] [--refine-max-level N "
@@ -692,7 +692,7 @@ int main(int argc, char **argv) {
     return write_minkowski_accel_track(&settings) == 0
                ? 0
                : (perror(settings.write_minkowski_accel_track_path), 1);
-#ifdef ENABLE_HDR_DEBUG
+#ifdef ENABLE_HDR_OUTPUT
   if (settings.frames_dir != NULL && settings.hdr_output_path != NULL) {
     fputs("--hdr-output is available only for a single-frame render.\n", stderr);
     return 2;

src/optics.c

@@ -8,7 +8,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-#ifdef ENABLE_HDR_DEBUG
+#ifdef ENABLE_HDR_OUTPUT
 #include <fitsio.h>
 #endif
 
@@ -457,7 +457,7 @@ int write_tonemapped_image(const char *path, const double *hdr, int width, int h
 #endif
 }
 
-#ifdef ENABLE_HDR_DEBUG
+#ifdef ENABLE_HDR_OUTPUT
 int write_hdr_fits(const char *path, const double *hdr, int width, int height,
                    double horizontal_fov_deg)
 {

src/optics.h

@@ -58,8 +58,8 @@ int splat_moffat_cached(double *hdr, int width, int height, double x, double y,
 /* Writes PNG when built with libpng; non-libpng builds use PPM fallback. */
 int write_tonemapped_image(const char *path, const double *hdr, int width,
                            int height);
-#ifdef ENABLE_HDR_DEBUG
-/* Test-build-only: writes the pre-tone-mapping framebuffer as 32-bit RGB FITS. */
+#ifdef ENABLE_HDR_OUTPUT
+/* Writes the pre-tone-mapping framebuffer as a 32-bit RGB FITS image. */
 int write_hdr_fits(const char *path, const double *hdr, int width, int height,
                    double horizontal_fov_deg);
 #endif