Thu, 21 Mar 2024 22:23:00 +0100
add correct interleaving of opaque and transparent sprites
1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 * Copyright 2023 Mike Becker. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
26 */
28 #include "ascension/text.h"
29 #include "ascension/context.h"
30 #include "ascension/error.h"
31 #include "ascension/shader.h"
33 #include <GL/glew.h>
35 static void asc_text_draw(AscText const *node) {
36 if (node->color.alpha == 0 || node->hidden || node->tex_id == 0) {
37 return;
38 }
40 // Upload model matrix
41 glUniformMatrix4fv(ASC_SHADER_SPRITE.base.model, 1,
42 GL_FALSE, node->base.final_transform);
44 // Upload surface
45 glActiveTexture(GL_TEXTURE0);
46 glBindTexture(GL_TEXTURE_RECTANGLE, node->tex_id);
47 glUniform1i(ASC_SHADER_SPRITE.surface, 0);
49 // Apply depth
50 glUniform1f(ASC_SHADER_SPRITE.depth, (float)(node->base.depth));
52 // Draw mesh
53 asc_primitives_draw_plane();
54 }
56 static void asc_text_update_transform(AscText *node) {
57 asc_transform_scale2i(node->base.local_transform, node->dimension);
58 asc_transform_translate2i(node->base.world_transform, node->position);
59 }
61 static void asc_text_update(AscText *node) {
62 // short circuit if fully transparent or hidden, we don't need anything
63 if (node->color.alpha == 0 || node->hidden) {
64 return;
65 }
67 // Generate new texture, if required
68 if (node->tex_id == 0) {
69 glGenTextures(1, &node->tex_id);
70 glBindTexture(GL_TEXTURE_RECTANGLE, node->tex_id);
71 glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
72 glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
73 asc_dprintf("Generated new texture for text node: %u", node->tex_id);
74 }
76 // Render text onto a surface
77 SDL_Surface *surface = TTF_RenderUTF8_Blended_Wrapped(
78 asc_font_cache_validate(node->font)->ptr,
79 node->text,
80 asc_col_sdl(node->color),
81 node->max_width
82 );
83 if (surface == NULL) {
84 asc_error(SDL_GetError());
85 return;
86 }
87 node->dimension.width = surface->w;
88 node->dimension.height = surface->h;
89 asc_node_update_transform((AscSceneNode *) node);
91 // Transfer Image Data
92 // TODO: move the image data transfer to a separate function - we will need it more often
93 glBindTexture(GL_TEXTURE_RECTANGLE, node->tex_id);
94 glPixelStorei(GL_UNPACK_ROW_LENGTH, surface->pitch / surface->format->BytesPerPixel);
95 glTexImage2D(GL_TEXTURE_RECTANGLE, 0, GL_RGBA,
96 surface->w, surface->h,
97 0, GL_BGRA, GL_UNSIGNED_BYTE, surface->pixels);
99 // Free the surface
100 SDL_FreeSurface(surface);
101 }
103 AscSceneNode *asc_text(int x, int y, char const *text) {
104 AscText *node = calloc(1, sizeof(AscText));
105 if (node == NULL) {
106 asc_error("Out of memory.");
107 return NULL;
108 }
110 node->base.render_group = ASC_RENDER_GROUP_SPRITE_BLEND;
111 node->base.free_func = (asc_scene_free_func) asc_text_free;
112 node->base.update_func = (asc_scene_update_func) asc_text_update;
113 node->base.transform_update_func = (asc_scene_update_func) asc_text_update_transform;
114 node->base.draw_func = (asc_scene_draw_func) asc_text_draw;
116 node->position.x = x;
117 node->position.y = y;
118 node->font = asc_context.active_font;
119 node->color = asc_context.ink;
120 if (text != NULL) {
121 node->text = strdup(text);
122 }
124 // initialize
125 asc_text_update(node);
126 asc_text_update_transform(node);
128 return &node->base;
129 }
131 void asc_text_free(AscText *node) {
132 asc_dprintf("Release text node texture: %u", node->tex_id);
133 glDeleteTextures(1, &node->tex_id);
134 free(node->text);
135 free(node);
136 }