Draw Manager: basic text overlay support

1 files changed, 199 insertions, 0 deletions

diff --git a/source/blender/draw/intern/draw_manager_text.c b/source/blender/draw/intern/draw_manager_text.c
new file mode 100644
index 00000000000..56255af98ce
--- /dev/null
+++ b/source/blender/draw/intern/draw_manager_text.c
@@ -0,0 +1,199 @@
+/*
+ * Copyright 2016, Blender Foundation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+/** \file blender/draw/intern/draw_manager_text.c
+ *  \ingroup draw
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_listbase.h"
+#include "BLI_string.h"
+#include "BLI_math.h"
+
+#include "BIF_gl.h"
+
+#include "GPU_matrix.h"
+
+#include "ED_screen.h"
+#include "ED_view3d.h"
+
+#include "UI_resources.h"
+#include "UI_interface.h"
+
+#include "WM_api.h"
+#include "BLF_api.h"
+
+#include "draw_manager_text.h"
+
+typedef struct ViewCachedString {
+	struct ViewCachedString *next, *prev;
+	float vec[3];
+	union {
+		unsigned char ub[4];
+		int pack;
+	} col;
+	short sco[2];
+	short xoffs;
+	short flag;
+	int str_len;
+
+	/* str is allocated past the end */
+	char str[0];
+} ViewCachedString;
+
+typedef struct DRWTextStore {
+	ListBase list;
+} DRWTextStore;
+
+DRWTextStore *DRW_text_cache_create(void)
+{
+	DRWTextStore *dt = MEM_callocN(sizeof(*dt), __func__);
+	return dt;
+}
+
+void DRW_text_cache_destroy(struct DRWTextStore *dt)
+{
+	BLI_freelistN(&dt->list);
+	MEM_freeN(dt);
+}
+
+void DRW_text_cache_add(
+        DRWTextStore *dt,
+        const float co[3],
+        const char *str, const int str_len,
+        short xoffs, short flag,
+        const unsigned char col[4])
+{
+	int alloc_len;
+	ViewCachedString *vos;
+
+	if (flag & DRW_TEXT_CACHE_STRING_PTR) {
+		BLI_assert(str_len == strlen(str));
+		alloc_len = sizeof(void *);
+	}
+	else {
+		alloc_len = str_len + 1;
+	}
+
+	vos = MEM_mallocN(sizeof(ViewCachedString) + alloc_len, __func__);
+
+	BLI_addtail(&dt->list, vos);
+
+	copy_v3_v3(vos->vec, co);
+	copy_v4_v4_uchar(vos->col.ub, col);
+	vos->xoffs = xoffs;
+	vos->flag = flag;
+	vos->str_len = str_len;
+
+	/* allocate past the end */
+	if (flag & DRW_TEXT_CACHE_STRING_PTR) {
+		memcpy(vos->str, &str, alloc_len);
+	}
+	else {
+		memcpy(vos->str, str, alloc_len);
+	}
+}
+
+void DRW_text_cache_draw(
+        DRWTextStore *dt,
+        View3D *v3d, ARegion *ar, bool depth_write)
+{
+	RegionView3D *rv3d = ar->regiondata;
+	ViewCachedString *vos;
+	int tot = 0;
+
+	/* project first and test */
+	for (vos = dt->list.first; vos; vos = vos->next) {
+		if (ED_view3d_project_short_ex(
+		        ar,
+		        (vos->flag & DRW_TEXT_CACHE_GLOBALSPACE) ? rv3d->persmat : rv3d->persmatob,
+		        (vos->flag & DRW_TEXT_CACHE_LOCALCLIP) != 0,
+		        vos->vec, vos->sco,
+		        V3D_PROJ_TEST_CLIP_BB | V3D_PROJ_TEST_CLIP_WIN | V3D_PROJ_TEST_CLIP_NEAR) == V3D_PROJ_RET_OK)
+		{
+			tot++;
+		}
+		else {
+			vos->sco[0] = IS_CLIPPED;
+		}
+	}
+
+	if (tot) {
+		int col_pack_prev = 0;
+
+		if (rv3d->rflag & RV3D_CLIPPING) {
+			ED_view3d_clipping_disable();
+		}
+
+		float original_proj[4][4];
+		gpuGetProjectionMatrix(original_proj);
+		wmOrtho2_region_pixelspace(ar);
+
+		gpuPushMatrix();
+		gpuLoadIdentity();
+
+		if (depth_write) {
+			if (v3d->zbuf) glDisable(GL_DEPTH_TEST);
+		}
+		else {
+			glDepthMask(GL_FALSE);
+		}
+
+		const int font_id = BLF_default();
+
+		const uiStyle *style = UI_style_get();
+
+		BLF_size(font_id, style->widget.points * U.pixelsize, U.dpi);
+
+		for (vos = dt->list.first; vos; vos = vos->next) {
+			if (vos->sco[0] != IS_CLIPPED) {
+				if (col_pack_prev != vos->col.pack) {
+					BLF_color4ubv(font_id, vos->col.ub);
+					col_pack_prev = vos->col.pack;
+				}
+
+				BLF_position(
+				        font_id,
+				        (float)(vos->sco[0] + vos->xoffs), (float)(vos->sco[1]), (depth_write) ? 0.0f : 2.0f);
+
+				((vos->flag & DRW_TEXT_CACHE_ASCII) ?
+				 BLF_draw_ascii :
+				 BLF_draw
+				 )(font_id,
+				   (vos->flag & DRW_TEXT_CACHE_STRING_PTR) ? *((const char **)vos->str) : vos->str,
+				   vos->str_len);
+			}
+		}
+
+		if (depth_write) {
+			if (v3d->zbuf) glEnable(GL_DEPTH_TEST);
+		}
+		else {
+			glDepthMask(GL_TRUE);
+		}
+
+		gpuPopMatrix();
+		gpuLoadProjectionMatrix(original_proj);
+
+		if (rv3d->rflag & RV3D_CLIPPING) {
+			ED_view3d_clipping_enable();
+		}
+	}
+}